# Twilio Documentation

> Reference documentation for all Twilio products. Code snippets, tutorials, and sample apps for common use cases and communications solutions.

## Authy: 2FA and Passwordless Login

* [Authy: 2FA and Passwordless Login](/docs/authy.md): Easily add two-factor authentication and passwordless logins via API or with our SDKs. Protect logins and step-up transactions with SMS, Voice, PushAuthentications, and TOTP through a simple API. Reduce fraud and increase user trust - follow these guides, reference docs, and tutorials.

## Building with AI

* [Building with AI](/docs/ai.md): Integrate Twilio APIs with AI coding agents using MCP servers, or use AI-powered communication products. Build faster with intelligent tools.
* [Twilio MCP server](/docs/ai/mcp.md): Connect AI coding agents to Twilio's API documentation with the Model Context Protocol server. Search over 1,800 endpoints and retrieve schemas on demand.
* [Twilio Skills for AI coding agents](/docs/ai/skills.md): Install Twilio Skills to teach AI coding agents which Twilio products to use, proven architecture patterns, and how to avoid common mistakes. Works with Claude Code, Cursor, Codex, and other Agent Skills-compatible tools.

## Conversation Intelligence (classic)

* [AI Nutrition Fact Labels](/docs/conversation-intelligence-classic/ai-nutrition-fact-labels.md): View AI Nutrition Fact Labels for the Twilio Conversation Intelligence (classic) Base Models.
* [Conversation Intelligence (classic) API Overview](/docs/conversation-intelligence-classic/api.md): Learn how to use the Twilio Conversation Intelligence (classic) API to analyze and extract actionable insights from conversations using AI and machine learning.
* [Conversation Intelligence (classic) - Service Resource](/docs/conversation-intelligence-classic/api/service-resource.md): Learn how to create, fetch, list, update, and delete a Service with Twilio's Conversation Intelligence (classic) API. Access detailed API reference and code samples.
* [Conversation Intelligence (classic) - Transcript Resource](/docs/conversation-intelligence-classic/api/transcript-resource.md): API reference for the Conversation Intelligence (classic) API Transcript resource, which represents a voice conversation that has automatically been converted to text through Twilio's transcription engine.
* [Conversation Intelligence (classic) - Transcript Sentence Subresource](/docs/conversation-intelligence-classic/api/transcript-sentence-subresource.md): Full API reference for the Transcript Sentence subresource in the Twilio Conversation Intelligence (classic) API. Sample code shows how to list the Sentences of a Transcript.
* [Conversation Relay integration for AI agent observability](/docs/conversation-intelligence-classic/conversation-relay-integration.md): Built-in AI agent observability with AI-powered language analysis
* [Customize Your Conversation Intelligence (classic) Configuration](/docs/conversation-intelligence-classic/customize.md): Learn more advanced concepts and implementations for Conversation Intelligence (classic), including using transcript sources outside of Twilio.
* [Generative Custom Operators](/docs/conversation-intelligence-classic/generative-custom-operators.md): LLM-backed Language Operators provide flexible and powerful conversational analysis supporting a wide range of sophisticated natural language understanding use cases.
* [Conversation Intelligence (classic)](/docs/conversation-intelligence-classic.md): Conversation Intelligence (classic) turns the content of your voice calls and messages into structured information to help you enrich customer profiles, optimize lead generation campaigns, address compliance issues, and assess agent performance across every conversation.
* [Language Operators](/docs/conversation-intelligence-classic/language-operators.md): Discover AI-powered Language Operators to analyze conversations and gain valuable insights. Learn about Pre-built and Custom Operators.
* [Conversation Intelligence (classic) onboarding guide](/docs/conversation-intelligence-classic/onboarding.md): Learn the basic concepts and how to configure Conversation Intelligence (classic) for AI insights from conversations. Set up via API or Twilio Console for seamless integration.
* [Pre-built Language Operators](/docs/conversation-intelligence-classic/pre-built-operators.md): Explore Pre-built Language Operators for Twilio Conversation Intelligence (classic), designed to classify, summarize, and extract key insights from conversation transcripts.

## Elastic SIP Trunking

* [Emergency Calling for SIP Trunking API](/docs/sip-trunking/api/emergency-calling.md): Twilio's Emergency Address registration enables emergency call routing to Public Safety Answering Points (PSAPs) in the US, Canada and the UK.
* [Elastic SIP Trunking REST API Reference](/docs/sip-trunking/api.md): Learn how to get started with Twilio Elastic SIP Trunking and view the REST API reference.
* [PhoneNumber Resource](/docs/sip-trunking/api/phonenumber-resource.md): Full API reference for the SIP Trunking PhoneNumber resource in the Twilio API. Learn how to create, read (list), and delete PhoneNumbers for SIP Trunks.
* [Trunk Resource](/docs/sip-trunking/api/trunk-resource.md): Full API reference for the SIP Trunking Trunk resource in the Twilio API. Learn how to create, read (list), and delete SIP Trunks.
* [Call Transfer via SIP REFER](/docs/sip-trunking/call-transfer.md): Learn how to transfer an active call with Twilio Elastic SIP Trunking using SIP REFER, including call flow, caller ID, call logs, and pricing details.
* [Elastic SIP Trunking Codecs](/docs/sip-trunking/codecs.md): Learn about supported codecs for Elastic SIP Trunking, including origination, termination, and codec priority.
* [Configure your Trunk using Twilio Interconnect](/docs/sip-trunking/configure-with-interconnect.md): Configure your SIP Trunk with Twilio Interconnect, allowing you to connect your SIP infrastructure using a private connection to an Elastic SIP Trunk.
* [Calls per Second (CPS) — Trunking Termination](/docs/sip-trunking/cps-trunk-termination.md): Learn about trunk-level Calls Per Second (CPS), parent account CPS, and debugger alerts for CPS limits.
* [Emergency Calling for SIP Trunking](/docs/sip-trunking/emergency-calling.md): Enable and configure Twilio's Emergency Calling, enabling emergency call routing to Public Safety Answering Points using Elastic SIP Trunking.
* [Extended Call Duration](/docs/sip-trunking/extended-call-duration.md): Extend the maximum call duration on Twilio Elastic SIP Trunking calls from 4 hours to 24 hours so your business can support conversations that run longer.
* [Elastic SIP Trunking](/docs/sip-trunking.md): Global pay-as-you-go connectivity for VoIP infrastructure with Twilio's Elastic SIP Trunking. Learn how to configure, troubleshoot, and connect your SBC or PBX SIP infrastructure to a Twilio Elastic SIP Trunk with our API reference documentation, tutorials, and usage guides.
* [IP Addresses for Elastic SIP Trunking Services](/docs/sip-trunking/ip-addresses.md): A complete list of Twilio's Gateway IP address ranges and ports, required for SIP signaling and RTP media traffic when using Elastic SIP Trunking.
* [Elastic SIP Trunking Configuration Guides](/docs/sip-trunking/sample-configuration.md): Use these Configuration Guides to help you connect your SIP Infrastructure (IP-PBX, SBC, etc) to a Twilio Elastic SIP Trunk.
* [Twilio SIP Trunking Scale and Limits](/docs/sip-trunking/scale-and-limits.md): This guide outlines the SIP Trunking limits you should be aware of when building with Twilio for standard accounts and when working with trial accounts.
* [SIP Header Manipulation](/docs/sip-trunking/sip-header-manipulation.md): Use SIP Header Manipulation to automatically modify phone numbers and user fields in SIP INVITE requests for Twilio Elastic SIP Trunking termination and origination calls.
* [Elastic SIP Trunking — Solution Blueprints](/docs/sip-trunking/solution-blueprints.md): Solution blueprints for your Twilio Elastic SIP Trunk including a list of contact centers, unified communications, and session border controllers.
* [Troubleshooting your Trunk](/docs/sip-trunking/troubleshooting.md): Troubleshoot your SIP Trunk, use the Twilio debugger, and explore common issues and possible solutions around SIP termination, origination, and audio issues.
* [Test your Elastic SIP Trunk](/docs/sip-trunking/trunk-verification.md): Read how to test your SIP Trunk for termination, origination, and emergency calling, as well as how to diagnose common problems.
* [Configure a 3CX PBX to use Twilio SIP Trunking](/docs/sip-trunking/trunking-3cx-pbx.md): Connect a 3CX PBX to Twilio Elastic SIP Trunking. Configure termination, origination, phone numbers, dialing routes, DID extensions, and emergency calling.
* [Protect your account with Voice Dialing Geographic Permissions](/docs/sip-trunking/voice-dialing-geographic-permissions.md): Protect your account with Voice Dialing Geographic Permissions - prevent IRSF toll-fraud

## Event Streams

* [Event Streams](/docs/events.md): Learn what you can do with Event Streams, an API that allows you to tap into a unified stream of every interaction sent or received on Twilio's network.

## Flex

* [Core concepts: Chat and Messaging](/docs/flex/admin-guide/core-concepts/chat-and-messaging.md): Understand how chat and messaging works within Flex.
* [Core concepts: Conversations](/docs/flex/admin-guide/core-concepts/conversations.md): Explore Flex Conversations, a feature supporting various asynchronous channels for both inbound and outbound communications using Flex UI 2.x.x and the Interactions API.
* [Core concepts: Flex UI](/docs/flex/admin-guide/core-concepts/flex-ui.md): Learn the core concepts and structure of Twilio Flex UI, including different user views, settings, SSO, themes, and plugins.
* [Core concepts](/docs/flex/admin-guide/core-concepts.md): Explore key concepts and building blocks for Twilio Flex.
* [Core concepts introduction](/docs/flex/admin-guide/core-concepts/introduction.md): This introduces Flex administrators to core concepts and products that Flex leverages to build your contact center.
* [Core concepts: Numbers](/docs/flex/admin-guide/core-concepts/numbers.md): This core concepts guide covers the various number types available to your Flex applications and includes provisioning and porting numbers.
* [Core concepts: Routing](/docs/flex/admin-guide/core-concepts/routing.md): Learn how Flex uses Taskrouter to route tasks to workers in your contact center workspace.
* [Core concepts: Studio Flows, Functions, Assets, TwiML](/docs/flex/admin-guide/core-concepts/studio-flows-functions-assets-twiml.md): Learn about the relationship of Studio Flows, REST API v2, Functions & Assets, and TwiML for Voice and SMS with Twilio Flex.
* [Core concepts: Voice](/docs/flex/admin-guide/core-concepts/voice.md): Learn about Flex voice features, including conferencing, secure payment options, and access to real-time audio streams.
* [Manage Flex Mobile (public beta)](/docs/flex/admin-guide/flex-mobile.md): Flex Mobile is a pre-built mobile app you can add to your existing Flex instance with no additional development effort.
* [Integrate Flex with Alvaria WFM](/docs/flex/admin-guide/integrations/alvaria.md): Learn how to integrate Alvaria Workforce Management with Twilio Flex for efficient contact center operations. Alvaria WFM enables you to efficiently forecast staff scheduling, schedule individual agents, and monitor schedule adherence.
* [Integrate Flex with Calabrio ONE WFM](/docs/flex/admin-guide/integrations/calabrio.md): Learn how Twilio Flex integrates with Calabrio ONE and how the workforce optimization solution can enhance contact center planning and operations.
* [Integrate Flex with Glance Cobrowse](/docs/flex/admin-guide/integrations/glance.md): Learn how to integrate Twilio Flex with Glance Cobrowse. This integration enables agents to launch a Cobrowse session to instantly join customers in viewing your app or website.
* [Google Dialogflow CX integration in Flex for virtual agents](/docs/flex/admin-guide/integrations/google-dialogflow-cx-native-integration.md): You can use Google Dialogflow CX Virtual Agent in Flex to handle incoming calls and conversations and route them to a live agent.
* [Integrate Flex with Lionbridge Language Cloud](/docs/flex/admin-guide/integrations/lionbridge-language-cloud.md): Explore Lionbridge Language Cloud for real-time translation in over 110 languages. Lionbridge Language Cloud is a real-time language translation solution that enables your agents and customers to each send and receive messages in their own native languages.
* [Integrate Mindful Feedback with Flex](/docs/flex/admin-guide/integrations/mindful-feedback.md): Explore Mindful Feedback, a tool that automatically collects customer feedback after any Flex interaction. View customer feedback within Flex UI on the integrated real-time reporting dashboard available for agents, supervisors and managers.
* [Integrate the Mindful platform With Flex](/docs/flex/admin-guide/integrations/mindful.md): Integrate Flex and Mindful for efficient customer callbacks. Learn to set up a SIP domain and trunk and to configure return call priority.
* [Integrate Flex with Puzzel WFM](/docs/flex/admin-guide/integrations/puzzel-wfm.md): Learn how to integrate Puzzel WFM with Twilio Flex. Puzzel WFM provides a simple, cloud-based platform that enables forecasting, scheduling, and adherence monitoring for your Twilio Flex workforce.
* [Set up Salesforce Service Cloud Voice (SCV) with Twilio](/docs/flex/admin-guide/integrations/salesforce-service-cloud-voice.md): Learn how to integrate Salesforce Service Cloud Voice to use Twilio as the Partner Telephony Provider.
* [Manage Flex-Salesforce call flows](/docs/flex/admin-guide/integrations/salesforce/call-flows.md): Learn how to accept incoming calls from new and existing contacts and make outgoing calls from your Flex-Salesforce integration.
* [Customize your Flex-Salesforce Integration](/docs/flex/admin-guide/integrations/salesforce/customize.md): Learn how to customize your Flex-Salesforce integration experience and call flows.
* [Integrate Flex with Salesforce](/docs/flex/admin-guide/integrations/salesforce.md): Use the Flex and Salesforce consoles to integrate your call center with Salesforce.
* [Upgrade Guide for Flex-Salesforce](/docs/flex/admin-guide/integrations/salesforce/upgrade-guide.md): Migrate your Flex-Salesforce Integration to use Native Outbound Dialing. Native Outbound Dialing enables you to take advantage of the increased stability and scale of the Flex platform and to gain access to additional features as they become available.
* [Integrate Flex with Spoke Phone (UCaaS)](/docs/flex/admin-guide/integrations/spoke-phone-ucaas.md): Explore Spoke Phone, a Unified Communications solution integrated with Twilio and Flex. Spoke Phone can serve as a full PBX replacement, enhancing connectivity.
* [Integrate Flex with Veridas Voice Biometrics](/docs/flex/admin-guide/integrations/veridas-voice-biometrics.md): Explore Veridas Voice Biometrics for a digital authentication solution. Validate the identity of your customers with just 3 seconds of their voice, in any language, and without the need of making them repeat any given sentence.
* [Manage Flex-Zendesk Call Flows](/docs/flex/admin-guide/integrations/zendesk/call-flows.md): Manage incoming and outgoing call flows in your Twilio Flex-Zendesk integration, including screen pop, interaction logging, custom tags, and click-to-dial.
* [Customize your Flex-Zendesk Integration](/docs/flex/admin-guide/integrations/zendesk/customize.md): Learn how to customize your Flex-Zendesk integration experience and call flows.
* [Integrate Flex with Zendesk](/docs/flex/admin-guide/integrations/zendesk.md): Use Twilio Flex and Zendesk together to offer an omnichannel and personalised experience to your Customers
* [Flex-Zendesk integration release notes](/docs/flex/admin-guide/integrations/zendesk/release-notes.md): Release notes for the Twilio Flex-Zendesk integration, covering added features, fixes, and changes across each plugin version.
* [Upgrade Guide for Flex-Zendesk](/docs/flex/admin-guide/integrations/zendesk/upgrade-guide.md): Upgrade your Flex-Zendesk integration to use Native Outbound Dialing.
* [Set up your Twilio Flex instance](/docs/flex/admin-guide/setup/account-creation.md): Sign up for Twilio and set up a cloud-hosted Twilio Flex contact center instance in minutes, then test the sample voice, SMS, and chat experience.
* [Alerts for contact center metrics in Flex (public beta)](/docs/flex/admin-guide/setup/alerts/alerts-contact-center-metrics.md): Configure alerts and notifications for real-time contact center metrics in Twilio Flex, including thresholds, webhooks, email, and browser push.
* [Configure pre-agent workflow with Studio](/docs/flex/admin-guide/setup/configure-pre-agent-workflow-with-studio.md): Use Twilio Studio to build pre-agent workflows for Flex, including IVR menus, chatbots, call deflection, and intelligent routing with Unified Profiles.
* [Manage Twilio Console users](/docs/flex/admin-guide/setup/console-users.md): Add and modify Flex users with administrator, developer, billing manager, or support roles in the Twilio Console.
* [Send Application-to-Person SMS in the US](/docs/flex/admin-guide/setup/conversations/a2p-10dlc.md): Register for an A2P use case, create a messaging service, and associate your A2P phone numbers with Flex Conversations.
* [Subscribe to Interactions events](/docs/flex/admin-guide/setup/conversations/configure-interactions-webhook.md): Create an Interactions API webhook and subscribe to events to get details when those events occur during Flex Conversations.
* [Configure with a Messaging Service (advanced)](/docs/flex/admin-guide/setup/conversations/configure-with-messaging-service-advanced.md): These advanced, optional steps to configure messaging are available to help customers with accounts created during or before December 2021.
* [Turn on content templates for Flex Conversations](/docs/flex/admin-guide/setup/conversations/content-templates.md): Learn how to turn on content templates so that agents can send predefined content in Flex Conversations.
* [Flex Conversations Roles](/docs/flex/admin-guide/setup/conversations/conversations-roles.md): Learn how Flex Conversations uses Conversations API roles to manage participant permissions at the Service and Conversation level, and the default roles Flex creates.
* [Leave and pause options for Conversations](/docs/flex/admin-guide/setup/conversations/leave-and-pause-for-conversations.md): Conversations in Flex provides a leave option that enables agents to temporarily close a conversation and move on to other tasks. If you want the pause and leave options to be available to agents, you must turn them on.
* [Manage Conversations Chat Addresses](/docs/flex/admin-guide/setup/conversations/manage-conversations-chat-addresses.md): Create a Flex Conversations Chat address in the Twilio Console and test it with the demo app.
* [Manage Conversations Addresses for Facebook Messenger (Public Beta)](/docs/flex/admin-guide/setup/conversations/manage-conversations-fbmessenger-addresses.md): Manage inbound Facebook messages by connecting your Facebook Business Page to Flex Conversations.
* [Manage Conversations SMS Addresses](/docs/flex/admin-guide/setup/conversations/manage-conversations-sms-addresses.md): Manage and configure your Flex phone number for the SMS channel in Flex Conversations. Test sending and receiving an SMS.
* [Manage Conversations WhatsApp Addresses](/docs/flex/admin-guide/setup/conversations/manage-conversations-whatsapp-addresses.md): Create a Flex Conversations WhatsApp address using the Twilio Console or the API. Set up a WhatsApp Sandbox to work with Flex Conversations.
* [Turn on messaging transfers for Conversations](/docs/flex/admin-guide/setup/conversations/messaging-transfers.md): When you turn on messaging transfers, agents can transfer a message (including the conversation history) to another agent or to a queue.
* [Overview of Address Management](/docs/flex/admin-guide/setup/conversations/overview-of-address-management.md): Learn how Flex Conversations uses Addresses to handle and connect new Conversations across SMS, WhatsApp, Chat, and Facebook Messenger channels.
* [Configure Agent Copilot (public beta)](/docs/flex/admin-guide/setup/copilot/configure.md): Agent Copilot uses generative AI to assist agents with wrap-up.
* [Agent Copilot: Configure customer highlights (public beta)](/docs/flex/admin-guide/setup/copilot/highlights.md): This guide describes how to configure customer highlights for Agent Copilot.
* [Agent Copilot for administrators (public beta)](/docs/flex/admin-guide/setup/copilot.md): Agent Copilot uses generative AI to assist agents.
* [Knowledge for Agent Copilot (public beta)](/docs/flex/admin-guide/setup/copilot/knowledge.md): Learn how to configure knowledge sources for Agent Copilot.
* [Agent Copilot: Enable additional languages for wrap-up notes (public beta)](/docs/flex/admin-guide/setup/copilot/languages.md): Agent Copilot uses generative AI to assist agents with wrap-up.
* [Agent Copilot: Known issues and limitations (public beta)](/docs/flex/admin-guide/setup/copilot/limitations.md): This page describes limitations of Agent Copilot.
* [AI Nutrition Facts for Agent Copilot (public beta)](/docs/flex/admin-guide/setup/copilot/nutritionfacts.md): Agent Copilot's AI qualities are outlined in the following Nutrition Facts label.
* [Configure real time-assist features for Agent Copilot (public beta)](/docs/flex/admin-guide/setup/copilot/real-time-assist.md): Learn how to configure real time-assist features for Agent Copilot to enhance agent productivity and customer interactions.
* [Agent Copilot: Configure wrap-up notes (public beta)](/docs/flex/admin-guide/setup/copilot/setup.md): This guide describes how to configure wrap-up notes for Agent Copilot.
* [Turn on a ringtone for inbound tasks](/docs/flex/admin-guide/setup/default-ringtone.md): Learn how to turn on a ringtone to play for inbound tasks in Twilio Flex.
* [Create email addresses](/docs/flex/admin-guide/setup/email/address-creation.md): Configure email addresses in Twilio Flex Console, choose a Studio Flow or webhook integration, and set a friendly from name so customers can email your contact center.
* [Add and authenticate email domains](/docs/flex/admin-guide/setup/email/domains.md): To prove that you own the domains you will use for Flex, you must add and authenticate your email domains in Twilio.
* [Enable Email in Flex](/docs/flex/admin-guide/setup/email/enable-email-in-flex.md): Learn to enable email as a channel in Twilio Flex.
* [Prepare your Flex account for email](/docs/flex/admin-guide/setup/email/flex-account-preparation.md): Before you can use email in Flex, you must prepare your Flex account.
* [Email in Flex for administrators](/docs/flex/admin-guide/setup/email.md): Learn to set up email in Twilio Flex.
* [Set up outbound email](/docs/flex/admin-guide/setup/email/outbound.md): Set up the email address that is used in the Flex UI when an agent starts a new outbound conversation.
* [Warm up an IP address for Email in Flex](/docs/flex/admin-guide/setup/email/warm-up-an-ip-address-for-email-in-flex.md): Warming up your IP allows you to gradually send more emails over your new IP to establish a good sender reputation.
* [Turn on language selection for agents (Public Beta)](/docs/flex/admin-guide/setup/enable-language-selection.md): Turn on language selection to give agents the option to set their display language.
* [Manage Flex UI users](/docs/flex/admin-guide/setup/flex-ui-users.md): Learn about Flex UI users (TaskRouter Workers), including available user roles, and how to view, create, and delete users.
* [Read-only Admin role](/docs/flex/admin-guide/setup/flex-ui-users/read-only-admin-role.md): As a Read-only Admin, you can enter Flex to view and troubleshoot issues.
* [Manage Flex logout settings](/docs/flex/admin-guide/setup/logout-settings.md): Specify when and how Flex UI users are automatically logged out when they become unavailable.
* [Test legacy SMS and chat](/docs/flex/admin-guide/setup/messaging/test-channels.md): Test sample experiences for legacy Voice, SMS, and Chat in Twilio Flex.
* [Securely embed Flex as an iframe](/docs/flex/admin-guide/setup/secure-iframe.md): Register and update your Allowed URLs list in the Twilio Console if you are embedding flex.twilio.com as an iframe.
* [Configure Auth0 IdP with Twilio Flex](/docs/flex/admin-guide/setup/sso-configuration/auth0.md): Auth0 single sign-on helps your users safely sign into Twilio Flex through the Auth0 sign-in. Learn how to configure Auth0 SSO with Flex.
* [Pass custom Entra ID attributes as Twilio Flex SAML claims](/docs/flex/admin-guide/setup/sso-configuration/azure-ad/custom-azure-ad-attributes-as-saml-claims.md): Use Microsoft Graph Explorer to pass custom Entra ID attributes as claims to your Flex application in the SAML response.
* [Configure Microsoft Entra ID with Flex](/docs/flex/admin-guide/setup/sso-configuration/azure-ad.md): Configure Entra ID as an identity provider for your Flex application.
* [Configure Google Single Sign-On (SSO) with Twilio Flex](/docs/flex/admin-guide/setup/sso-configuration/google.md): Google Single Sign-On helps your users safely sign into Twilio Flex via Google sign-in. Learn how to configure Google SSO with Twilio Flex here.
* [Configuring SSO and IdP in Flex](/docs/flex/admin-guide/setup/sso-configuration.md): Learn how to configure single sign-on (SSO) and identity provider (IdP) in Twilio Flex for popular identity providers.
* [Flex Insights User Roles](/docs/flex/admin-guide/setup/sso-configuration/insights-user-roles.md): Provision users and assign roles in Flex Insights using Okta. Learn about the roles and access to analytical dashboards that you can enable in Flex Insights.
* [Flex SSO URL Migration Guide](/docs/flex/admin-guide/setup/sso-configuration/migration-guide.md): Learn how to migrate your Flex SSO to a solution with enhanced security using OAuth 2.0.
* [Configure Okta IdP with Flex](/docs/flex/admin-guide/setup/sso-configuration/okta.md): Have your agents log in to Twilio Flex using Okta. Learn how to integrate Okta with Twilio Flex as a SAML 2.0 identity provider with this step-by-step guide.
* [Configure Salesforce SSO with Flex](/docs/flex/admin-guide/setup/sso-configuration/salesforce.md): Step-by-step instructions for setting up Salesforce single sign-on (SSO) with Twilio Flex as a SAML 2.0 identity provider, including certificate setup.
* [Self-hosted Flex: additional SSO configuration](/docs/flex/admin-guide/setup/sso-configuration/self-hosted-sso.md): Learn about the additional SSO configuration needed for self-hosted Flex deployments.
* [System checkup](/docs/flex/admin-guide/setup/system-checkup.md): System checkup detects common issues with your Flex configuration.
* [Teams in Flex (Public Beta)](/docs/flex/admin-guide/setup/teams.md): Group Flex users together for easier user management, reporting, and oversight.
* [Topics, subtopics, and disposition codes (Public Beta)](/docs/flex/admin-guide/setup/topics.md): Use topics to automatically categorize customer conversations.
* [Add Flex customer history (Public Beta)](/docs/flex/admin-guide/setup/unified-profiles/customer-history-and-interaction.md): Learn how to configure Flex customer history and interaction data in Unified Profiles.
* [Enrich profiles with Flex interaction data](/docs/flex/admin-guide/setup/unified-profiles/enrichment.md): Enrich Segment profiles with Flex customer interaction data. Flex sends engagement events and updates profile traits after each interaction.
* [Confirm or update your customer identifier settings (Public Beta)](/docs/flex/admin-guide/setup/unified-profiles/identifiers.md): Unified Profiles uses customer identifiers to search for customer profiles. You can configure these identifiers.
* [Unified Profiles in Flex for administrators (Public Beta)](/docs/flex/admin-guide/setup/unified-profiles.md): Provide your teams with information about each customer to enhance their understanding of customer intent and enable them to personalize every conversation.
* [Known issues and limitations in Unified Profiles in Flex (Public Beta)](/docs/flex/admin-guide/setup/unified-profiles/limitations.md): Review known issues and limitations in Unified Profiles in Flex, including phone number formats, Flex UI version requirements, and common sync errors.
* [Connect your Segment space (Public Beta)](/docs/flex/admin-guide/setup/unified-profiles/segment-space.md): Learn how to connect your Segment space to work with Unified Profiles.
* [Set up and configure Unified Profiles in Flex (Public Beta)](/docs/flex/admin-guide/setup/unified-profiles/setup.md): Learn how to set up and configure Unified Profiles in Flex.
* [Configure customer details (Public Beta)](/docs/flex/admin-guide/setup/unified-profiles/setup/configure-ui/customer-details.md): Enable the customer details component to display customer profile information to your agents in Flex.
* [Customer highlights (Public Beta)](/docs/flex/admin-guide/setup/unified-profiles/setup/configure-ui/customer-highlights.md): Set up and configure customer highlights in Flex to show agents an AI-generated summary of a customer's profile before and during a task.
* [Configure customer history (Public Beta)](/docs/flex/admin-guide/setup/unified-profiles/setup/configure-ui/customer-history.md): Enable the customer history component to display customer events to your agents in Flex UI.
* [Configure customer header and search (Public Beta)](/docs/flex/admin-guide/setup/unified-profiles/setup/configure-ui/header-search.md): Configure the customer header and profile search in Flex to control what agents see at a glance and which identifiers agents can search by.
* [Configure Flex UI components (Public Beta)](/docs/flex/admin-guide/setup/unified-profiles/setup/configure-ui.md): Configure how customer profile data is shown to agents in your contact center.
* [Wrap-up notes (Public Beta)](/docs/flex/admin-guide/setup/unified-profiles/setup/configure-ui/wrap-up-notes.md): Enable the Flex wrap-up notes component to show agents an AI-generated conversation summary, predicted customer sentiment, and a disposition code.
* [Configure the Flex Dialpad](/docs/flex/admin-guide/setup/voice/dialpad-configure.md): Enable and configure outbound dialing in Flex using Flex Dialpad.
* [Enable the Flex Dialpad](/docs/flex/admin-guide/setup/voice/dialpad/enable.md): Flex Dialpad allows agents to place outbound calls within the Flex UI. This page explains how to enable Flex Dialpad.
* [Flex Dialpad Overview](/docs/flex/admin-guide/setup/voice/dialpad.md): Get started with the Flex Dialpad and review the resources available for developers and administrators.
* [Flex on Azure Virtual Desktop or Windows 365 Cloud PC](/docs/flex/admin-guide/setup/voice/flex-azure-vdi.md): Overview and setup for Flex on Azure Virtual Desktop or Windows 365 Cloud PC
* [Flex on Citrix VDI](/docs/flex/admin-guide/setup/voice/flex-citrix-vdi.md): Overview and setup for Flex Citrix VDI.
* [Test Voice](/docs/flex/admin-guide/setup/voice/test.md): Test the voice experience in Flex UI 1.x.x by answering a test voice call. 
* [Build an IVR for Flex with Twilio Studio](/docs/flex/admin-guide/tutorials/ivr.md): Learn to route calls with an IVR menu in Twilio Studio as part of the Flex system, reducing agent calls and enhancing efficiency.
* [Routing Part 2: Set Up Queues and Skills-based Routing](/docs/flex/admin-guide/tutorials/queues-and-skills-based-routing.md): Set up task queues for your Twilio Flex contact center and enable skills-based routing by creating your TaskRouter Workflows and Studio Flows for Flex.
* [Routing Part 1: Assign skills to your Flex agents](/docs/flex/admin-guide/tutorials/skills-assignment.md): Configure skills in the Twilio Flex Admin UI and assign them to your agents to enable skills-based routing in your Flex contact center.
* [Manage legacy SMS addresses](/docs/flex/admin-guide/tutorials/sms-setup.md): Set up a new legacy SMS address to route incoming SMS messages for a phone number into Flex. Learn to manage SMS addresses, create new conversations, and sync with Flex Proxy Service.
* [Handle a Voice Contact](/docs/flex/admin-guide/tutorials/voice-setup.md): Purchase a new Twilio number, configure it with a Studio Flow for handling calls, and test the voice experience on your Flex account.
* [What is Twilio Flex?](/docs/flex/admin-guide/what-is-twilio-flex.md): Twilio Flex is a digital engagement center for Sales and Service that provides a single UI and native channels to manage omnichannel customer experiences.
* [AI overview (Public Beta)](/docs/flex/ai.md): Twilio's AI capabilities combine the power of large language models (LLMs) with real-time customer and communications data to power Unified Profiles and Agent Copilot in Flex.
* [Checklist for setting up Twilio Flex](/docs/flex/building-checklist.md): Plan and set up Flex efficiently by following this checklist.
* [Get Started with Flex Conversations](/docs/flex/conversations.md): Get started with Flex Conversations, which uses next-generation architecture for async channel capabilities in Flex.
* [Flex alerts: Rules API (public beta)](/docs/flex/developer/alerts/alerts-insights-api.md): REST API reference for Flex alerts Insights rules. Create, list, fetch, update, and delete alert rules and thresholds for contact center metrics.
* [Flex alerts: Notification configuration API (public beta)](/docs/flex/developer/alerts/notifications-api.md): REST API reference for Flex alerts notification configurations. Create, fetch, edit, and delete in-app, webhook, and email notification settings.
* [The appConfig.js object](/docs/flex/developer/config/appconfigjs.md): Learn how to manage your self-hosted Flex UI app configuration.
* [Flex Configuration REST API](/docs/flex/developer/config/flex-configuration-rest-api.md): Manage and modify your Flex Configuration properties via REST API. Oversee, retrieve, and update API Configuration resources efficiently.
* [Known issue: Self-hosted Flex 2.7.0 and later requires specific react-scripts version](/docs/flex/developer/config/known-issue-react-scripts-version.md): If you use self-hosted Flex and your custom application uses react-scripts v5, you must apply a workaround to use Flex UI 2.7.0 or later due to a react-scripts issue. Without the workaround, Flex will fail to initialize.
* [Best Practices](/docs/flex/developer/conversations/best-practices.md): Follow these best practices for setting up Twilio Flex Conversations.
* [Conversations FAQ and Troubleshooting](/docs/flex/developer/conversations/faq-and-troubleshooting.md): Read answers to frequently asked questions about building with Flex Conversations.
* [Flex Conversations](/docs/flex/developer/conversations.md): Dive into the architectural overview, inbound and outbound flows on a messaging channel when using Flex Conversations in Flex UI 2.x.x.
* [Integrate a Custom Chat Client with Flex](/docs/flex/developer/conversations/integrate-a-custom-chat-client-with-flex.md): Integrate custom chat with Flex UI 2.x.x and hand off incoming Conversation messages to your agents.
* [Integrate the Twilio Webchat React app with Flex](/docs/flex/developer/conversations/integrate-twilio-webchat-react-app.md): Explore an open-source React demo of a webchat widget that you can integrate with Flex UI 2.x.x.
* [Channels Subresource](/docs/flex/developer/conversations/interactions-api/channels-subresource.md): Fetch and update interaction channels using this Flex Interaction endpoint.
* [Interactions API](/docs/flex/developer/conversations/interactions-api.md): Review the list of Interactions API subresources and attributes that are consumed by the Flex UI and Insights.
* [Interaction Channel Participants](/docs/flex/developer/conversations/interactions-api/interaction-channel-participants.md): Manage participants in a Flex Interaction. Examples include how to use the API to wrap up and complete a Flex Conversations task for an agent and how to change an agent's reservation status to Completed.
* [Interactions resource](/docs/flex/developer/conversations/interactions-api/interactions.md): API reference for the Flex Interactions resource. Create inbound and outbound interactions for SMS, WhatsApp, web, chat, email, and Messenger channels.
* [Invites Subresource](/docs/flex/developer/conversations/interactions-api/invites-subresource.md): Use the Interaction Channel Invite subresource to add an agent as a new participant to an existing Flex 2.x.x interaction channel.
* [Known Issues](/docs/flex/developer/conversations/known-issues.md): View known issues and workarounds for Flex Conversations.
* [File Attachments and API Limits](/docs/flex/developer/conversations/limits.md): View limits for Flex Conversations attachments and APIs.
* [Park an Interaction](/docs/flex/developer/conversations/park-an-interaction.md): Learn how to remove agents but keep a Flex UI 2.x.x interaction open while waiting for more information. This page includes example commands and responses.
* [Receive Inbound Messages with Flex Conversations Channels](/docs/flex/developer/conversations/receive-inbound-messages-from-sms-and-whatsapp.md): Learn how to configure inbound messages on different Flex Conversations channels.
* [Register a webhook to receive Interactions events](/docs/flex/developer/conversations/register-interactions-webhooks.md): Create an Interactions API webhook and subscribe to events to get details when those events occur during Flex Conversations.
* [Send Outbound Messages with Flex Conversations Channels](/docs/flex/developer/conversations/send-outbound-messages-via-sms-and-whatsapp.md): Send an outbound message using Flex Conversations channels, such as SMS, WhatsApp, or chat, in Flex UI 2.x.x.
* [Cookies and the Web Storage API in Webchat 3.x.x](/docs/flex/developer/conversations/webchat/cookies-and-web-storage.md): This page discusses cookies, local storage, and session storage, and how Flex Webchat utilizes each one.
* [Webchat 3.x.x overview](/docs/flex/developer/conversations/webchat.md): Flex Webchat is a natively integrated chat widget that you can embed on your website. The widget helps your customers chat with an agent without leaving your webpage.
* [Migrate to Webchat 3.x.x](/docs/flex/developer/conversations/webchat/migrate.md): Understand the differences between webchat versions. Learn how to migrate to Webchat 3.x.x.
* [Using pre-engagement form data and context in Webchat 3.x.x](/docs/flex/developer/conversations/webchat/pre-engagement-and-context.md): Learn about using pre-engagement forms and context to gather user information before the start of a chat.
* [Webchat 3.x.x security](/docs/flex/developer/conversations/webchat/security.md): Webchat 3.x.x includes enhanced security measures, including a randomly generated deployment key, fingerprinting, and the ability to add allowed origins.
* [Set up and use Webchat 3.x.x](/docs/flex/developer/conversations/webchat/setup.md): Get started with Webchat for Twilio Flex. Learn how to add this chat widget to your web applications and understand the chat widget's default behavior.
* [Use custom styling for Webchat components in Webchat 3.x.x](/docs/flex/developer/conversations/webchat/styling-customizations.md): Learn how to customize the style of Webchat 3.x.x components by overriding CSS classes.
* [WebChats Resource](/docs/flex/developer/conversations/webchats-resource.md): Simplify creating a web channel for starting a Flex Conversations chat in Flex UI 2.x.x.
* [Agent Copilot: wrap-up notes webhook (public beta)](/docs/flex/developer/copilot-webhooks.md): Configure a wrap-up notes webhook to send Agent Copilot notes from Flex to your CRM or database, and learn the note\_created and note\_updated event payloads.
* [Agent Copilot: Upload your knowledge sources using the API (public beta)](/docs/flex/developer/copilot/upload-source-api.md): Step-by-step guide on how to use the Knowledge API to upload your sources for Agent Copilot.
* [Manage email conversations](/docs/flex/developer/email/conversations.md): Email in Flex uses the Conversations API as a basis for message orchestration.
* [Email in Flex limitations](/docs/flex/developer/email/limitations.md): This page describes limitations of Email in Flex.
* [Customize the Email in Flex UI](/docs/flex/developer/email/ui-customization.md): Email in Flex uses the same programmable model as other parts of the Flex UI. This means that you can add, replace, and remove the new email editor components or invoke various actions related to email in the Flex UI.
* [Flex SDK authentication](/docs/flex/developer/flex-sdk/authentication.md): Authenticate the Flex SDK using single sign-on (SSO), a JWE token, or your own custom authentication method with the Flex API and OAuth.
* [Getting started](/docs/flex/developer/flex-sdk/getting-started.md): Get started with the Flex SDK. Create a Vite app, install the @twilio/flex-sdk package, and initialize the client to build a custom contact center.
* [Flex SDK glossary](/docs/flex/developer/flex-sdk/glossary.md): A glossary of key Flex SDK terms for workers, tasks, voice calls, conversations, authorization, and the SDK client to help you build a contact center.
* [Flex SDK overview](/docs/flex/developer/flex-sdk.md): The Flex SDK lets you embed Twilio Flex Contact Center as a Service (CCaaS) features into any web app, including TaskRouter, Voice, and Conversations.
* [Flex SDK methods](/docs/flex/developer/flex-sdk/sdk-methods.md): Reference for Flex SDK methods, including worker, task, voice, conversation, supervisor, authorization, and SDK client methods, with code examples.
* [Flex developer documentation](/docs/flex/developer.md): Twilio Flex allows developers to customize the digital sales and service experience, providing full control over customer engagement.
* [Export Data from Flex Insights via API](/docs/flex/developer/insights/api/export-data.md): Learn how to export reports from within Flex Insights to store the data in a warehouse of your own.
* [Flex Insights API General Usage](/docs/flex/developer/insights/api/general-usage.md): Authenticate with the Flex Insights API using a Super Secured Token (SST) and Temporary Token (TT), then make API calls, log out, and delete a profile.
* [Mapping Global Identifiers to Workspace Identifiers](/docs/flex/developer/insights/api/mapping-identifiers.md): Flex Insights can identify reports, metrics, dashboards, and other objects using multiple identifiers. Learn why these identifiers are useful, and how to map global identifiers to workspace identifiers.
* [Run Flex Insights on a Custom Domain](/docs/flex/developer/insights/custom-domain.md): Learn how to run Flex Insights Historical Reporting on a custom domain in self-hosted Flex environments and enable access from localhost.
* [Custom Media attached to Conversations](/docs/flex/developer/insights/custom-media-attached-conversations.md): Learn how to attach custom media to a Flex Insights Conversation.
* [Turn on dual-channel recording](/docs/flex/developer/insights/enable-dual-channel-recordings.md): Unlock advanced call analysis with dual-channel recording. Enhance transcription, keyword analysis, and playback using Flex Insights, the Twilio Console, and Voice API.
* [Add additional TaskRouter data](/docs/flex/developer/insights/enhance-integration.md): Learn how to add additional data to TaskRouter to enhance your Flex Insights reports and link multiple communications to a single customer.
* [HIPAA for Flex Insights Historical Reporting](/docs/flex/developer/insights/hipaa-flex-insights-historical-reporting.md): Flex Insights adheres to HIPAA guidelines, safeguarding personal health data by removing identifiable information from Historical Reporting.
* [Building with Flex Insights](/docs/flex/developer/insights.md): Enhance your Flex Insights integration and export data via custom code development.
* [Embedding Dashboards](/docs/flex/developer/insights/insights-dashboards-embedding.md): Learn how to enable and work with Insights - Programmable Dashboards on your Flex application.
* [Dashboards Programmability](/docs/flex/developer/insights/insights-dashboards-programmability.md): Learn to customize project and analytical dashboards filters to control how they appear.
* [Label Data for Flex Insights](/docs/flex/developer/insights/labels.md): Enhance efficiency in Historical Reporting with Labels. Manage attributes and labels to maximize data value without reaching the limit for unique attribute labels.
* [Secure Playback of Recordings from Custom Storage](/docs/flex/developer/insights/playback-recordings-custom-storage.md): Manage user access to call recordings with Flex Insights. Create custom authorization of users, log access to individual recordings, and decrypt recordings.
* [Workforce Management Real-Time Adherence](/docs/flex/developer/insights/real-time-adherence.md): Monitor real-time activity and status of Flex contact center agents using Workforce Management Real-Time Adherence Feed. Get JSON-formatted agent updates via HTTPS.
* [TaskRouter Data in Flex Insights](/docs/flex/developer/insights/taskrouter-data.md): Understand what data is available from TaskRouter in Flex Insights.
* [The Plugins API](/docs/flex/developer/plugins/api.md): Learn about the Plugins API, which defines which plugins the Flex UI loads during initialization. The Plugins API is used by the Flex Plugin CLI and the Custom Plugins Dashboard to simplify common workflows.
* [Plugin Configuration Resource](/docs/flex/developer/plugins/api/plugin-configuration.md): Create and manage custom contact center plugin configurations using the Flex API.
* [Plugin Version Resource](/docs/flex/developer/plugins/api/plugin-version.md): Create, fetch, or read all or a specific Flex plugin version using the Flex API.
* [Plugin Resource](/docs/flex/developer/plugins/api/plugin.md): The Plugin Resource serves as an identifier for the Plugin itself. You can find information about a given plugin, like its name, description, and the account that owns the plugin.
* [Releasing Flex plugins with the Plugins API](/docs/flex/developer/plugins/api/release-guide.md): Create, deploy and manage Flex plugin versions using the Plugins API.
* [Create a new release with new and updated Plugins](/docs/flex/developer/plugins/api/release-update.md): This guide explains how to roll out a new version of a plugin that is already active on your contact center or introduce a new plugin in your Flex contact center.
* [Plugin Release Resource](/docs/flex/developer/plugins/api/release.md): Activate a Configuration on a Flex project using the Plugin Release resource. Manage multiple plugins, audit changes, and implement releases efficiently.
* [Rolling Back a Release using Plugins API](/docs/flex/developer/plugins/api/rollback.md): Use the Plugins API to quickly and simply roll back a release. 
* [How to call Twilio Functions from a Flex plugin](/docs/flex/developer/plugins/call-functions.md): Learn how to use Twilio's serverless Functions to make secure requests from custom Plugins in your Flex contact center.
* [Archive Plugins and Configurations](/docs/flex/developer/plugins/cli/archive.md): Archive plugins effectively with the Flex API. Prevent accidental redeployments and view archived plugins in the Flex Dashboard.
* [Common Use Cases](/docs/flex/developer/plugins/cli/common-uses.md): Read the common use cases for the Flex Plugins CLI, including sample commands and responses.
* [Validate, deploy, and release a plugin using the Flex Plugins CLI](/docs/flex/developer/plugins/cli/deploy-and-release.md): Deploy your plugins using the command line with the Flex Plugins CLI. Learn how to manage releases and configurations for multiple Twilio accounts.
* [Flex Plugins CLI](/docs/flex/developer/plugins/cli.md): Develop, test, and release your Flex plugins using the Flex CLI.
* [Install Flex Plugins CLI](/docs/flex/developer/plugins/cli/install.md): Manage and install Flex plugins with the Flex Plugins CLI. Migrate existing plugins, initiate new ones, or remove old installations.
* [Plugins CLI Reference](/docs/flex/developer/plugins/cli/reference.md): Use the Flex Plugins CLI to manage, build, and deploy Twilio Flex plugins.
* [Run Multiple Plugins Locally Using the Flex Plugins CLI](/docs/flex/developer/plugins/cli/run-multiple-plugins.md): Use the Flex CLI to test and load multiple plugins both locally and remotely in your Flex application.
* [Upgrade Flex Plugins CLI](/docs/flex/developer/plugins/cli/upgrade.md): Upgrade the Flex Plugins CLI. Review resources for migrating existing plugins to use the latest CLI version.
* [Custom Plugins Dashboard](/docs/flex/developer/plugins/dashboard.md): Manage custom plugins, view the history of custom plugin releases, and roll back to prior deployments with the Custom Plugins dashboard.
* [Debugging a Flex Plugin with VS Code](/docs/flex/developer/plugins/debugging-with-vscode.md): Set up Visual Studio (VS) Code for local Flex Plugin debugging. Learn to configure plugins and efficiently manage breakpoints.
* [Environment variables in Flex Plugins](/docs/flex/developer/plugins/environment-variables.md): Manage Flex apps using multiple accounts for different environments. Use the Flex Plugins CLI and environment variables for effective deployment and integration.
* [Localize a plugin (Public Beta)](/docs/flex/developer/plugins/localize-a-plugin.md): Learn how to configure your custom plugin to display in another language.
* [Migrate Legacy Plugins to the CLI](/docs/flex/developer/plugins/migrate.md): Migrate from Flex Plugin Builder to the Twilio CLI Flex plugin. Learn how you can migrate and manage your plugins with the new CLI.
* [Flex Plugin Library](/docs/flex/developer/plugins/plugin-library.md): The Flex Plugin Library is a collection of ready-to-install Flex plugins for common contact center use cases.
* [Plugins Resource Limits](/docs/flex/developer/plugins/plugins-resource-limits.md): Manage Flex plugins effectively with restrictions on quantity, versions, and file size to optimize your Flex application's capabilities.
* [Selecting React versions for Flex](/docs/flex/developer/plugins/react-versions.md): Learn how to select and verify React and ReactDOM versions for a Flex application. Includes installation guidelines for new and existing plugins.
* [Keeping Plugins Up-To-Date](/docs/flex/developer/plugins/updating.md): Upgrade the Flex Plugins CLI and dependencies. You can try out new features in your latest plugins without risking backwards-incompatible changes in your other codebases.
* [Getting Started with TaskRouter](/docs/flex/developer/routing.md): Leverage TaskRouter for attribute-based routing in Flex contact centers. Enhance agent actions and visibility with dynamic task data exposure.
* [Flex UI and Flex Plugins](/docs/flex/developer/ui-and-plugins.md): A high-level overview of Twilio Flex Plugins, the recommended way of customizing your Flex UI, with links to more in-depth documentation.
* [Override Flex UI 2.x.x themes, branding and styling](/docs/flex/developer/ui-and-plugins/themes-branding-styling.md): Twilio Flex UI offers a range of customizations. Learn how to configure a base theme, override base themes and individual components, and apply your custom theme.
* [Add Task and Theme Context to Components](/docs/flex/developer/ui/add-component-context.md): Learn how to add context such as Task and Theme data into your Flex custom component.
* [Add Components to Flex UI](/docs/flex/developer/ui/add-components-flex-ui.md): Learn how to add a custom component to your Flex application using a plugin.
* [Use Apollo Client with Flex UI](/docs/flex/developer/ui/apollo-client.md): Learn how to adjust your Apollo Client configuration to work with Flex UI and your custom GraphQL APIs.
* [Flex UI Components](/docs/flex/developer/ui/components.md): Learn how to programmatically add, replace, or remove Twilio Flex UI components.
* [Create and Style Custom Components](/docs/flex/developer/ui/creating-styling-custom-components.md): Build custom Flex components and read about best practices using the Twilio Paste design system and Emotion library for bundling styles and plugin code.
* [Create Custom Views and Routes](/docs/flex/developer/ui/custom-views-and-routes.md): Twilio Flex allows you to build custom views and routes for your contact center using familiar libraries like React Router.
* [Error Handling and Debugging](/docs/flex/developer/ui/errors-and-debugging.md): Learn how to handle errors, retrieve logs, and use Flex UI in Degraded Mode.
* [The Flex UI](/docs/flex/developer/ui.md): Use the Twilio Flex UI component library to build custom user experiences and custom behaviors for the Flex Agent Desktop and Flex Supervisor Desktop.
* [Flex UI local logging](/docs/flex/developer/ui/local-logging.md): Capture client-side logs into a text file that you can share with Twilio support to help with troubleshooting.
* [Migrate from Flex UI 1.x.x to 2.x.x](/docs/flex/developer/ui/migration-guide.md): Migrate smoothly from Flex UI 1.x.x to 2.x.x. This guide outlines UI and SDK changes that can affect your customizations.
* [Flex UI 2.x.x updates that can affect your customizations](/docs/flex/developer/ui/migration-guide/migration-guide-2x-updates.md): This page describes Flex UI updates that you should be aware of when migrating to Flex UI 2.x.x.
* [Update plugins for Flex UI 2.x.x](/docs/flex/developer/ui/migration-guide/migration-guide-update-plugins.md): This page explains how to update your plugins when migrating to Flex UI 2.x.x
* [Modify Flex UI Keyboard Shortcuts](/docs/flex/developer/ui/modify-keyboard-shortcuts.md): Flex UI 2.1 includes a customizable and programmable keyboard shortcuts menu for the most common contact center operations.
* [Overview of Flex UI programmability options](/docs/flex/developer/ui/overview-of-flex-ui-programmability-options.md): Manage your Flex UI 2.x.x instance with Flex Manager. Learn to customize different components and manage states and task channels.
* [Real-Time Queues View Programmability](/docs/flex/developer/ui/queues-view-programmability.md): Customize the Real-Time Queues View to display the queue statistics that you want to monitor in your contact center.
* [Use Redux with Flex](/docs/flex/developer/ui/redux.md): Learn about Redux and how it can help data move through your omnichannel contact center with Twilio Flex.
* [Flex UI Requirements](/docs/flex/developer/ui/requirements.md): See software, equipment, and networking requirements for running Flex in your contact center.
* [Sounds and audio in Flex](/docs/flex/developer/ui/sound-and-audio.md): Leverage the Flex AudioPlayerManager API for sound implementation. Manage playing, stopping, and muting sounds efficiently while handling media errors.
* [Advanced Team View Filters](/docs/flex/developer/ui/team-view-filters.md): Customize Team View Filters in your Flex application to help supervisors with agent filtering.
* [Developer Guide to Troubleshooting the Flex UI](/docs/flex/developer/ui/troubleshoot-the-flex-ui.md): Monitor and maintain your Flex application with Flex UI and Twilio Console debugging tools. Retrieve error reports and logs, and send them to error monitoring systems or directly to Twilio.
* [Use Twilio Paste with a Flex Plugin](/docs/flex/developer/ui/use-paste-with-a-plugin.md): Learn how to use Twilio Paste design tokens, leverage it on a Flex plugin, or customize Paste elements using a Flex method.
* [Use UI Actions](/docs/flex/developer/ui/use-ui-actions.md): Leverage Flex UI's emitted event data with Actions Framework. Register, modify, and replace actions, create custom alerts, and monitor incoming calls.
* [Web Accessibility](/docs/flex/developer/ui/web-accessibility.md): Flex UI 2.x.x includes enhanced support for WCAG 2.1 AA compliance. This page explains accessibility features that Flex UI supports and the accessibility tools that Flex UI provides. 
* [Work with Components and Props](/docs/flex/developer/ui/work-with-components-and-props.md): Work with programmable Flex UI 2.0 components and props.
* [Work with Notifications](/docs/flex/developer/ui/work-with-notifications.md): Manage and customize notifications through Flex UI's client-side API. Use NotificationBar for icons and actions, and enable browser notifications.
* [Unified Profiles Container (Public Beta)](/docs/flex/developer/unified-profiles-container.md): Customize the Flex Unified Profiles container: turn it on, add custom tabs, reorder built-in tabs, and program its components with the Flex UI API.
* [Flex Teams API (public beta)](/docs/flex/developer/user-management/flex-teams-api.md): Use the Flex Teams REST API to group users together for easier user management, reporting, and oversight.
* [Flex User Token API (public beta)](/docs/flex/developer/user-management/flex-token-api.md): Use the Flex User Token API to generate JSON Web Encryption (JWE) tokens that authenticate Flex users and grant secure access to the Flex application.
* [Flex Users API (public beta)](/docs/flex/developer/user-management/flex-users-api.md): Use the Flex Users API to list, provision, deprovision, and fetch Flex users and their associated TaskRouter Workers and Insights Users.
* [How to Implement Click-to-Dial](/docs/flex/developer/voice/dialpad-click-to-dial.md): Implement click-to-dial functionality using Flex's native outbound dialing capabilities. Integrate with CRMs and customize calls so you can initiate calls seamlessly.
* [Voice in Twilio Flex](/docs/flex/developer/voice.md): Set up basic inbound and outbound calls for your Cloud Contact Center using Twilio's Programmable Voice API
* [Change your language (Public Beta)](/docs/flex/end-user-guide/change-display-language.md): Learn how to set which language you want to use for Flex.
* [Chat Attachments](/docs/flex/end-user-guide/chat-attachments.md): Learn to send and receive chat attachments in Flex UI 1.x.x.
* [Send an attachment](/docs/flex/end-user-guide/conversations/messaging-attachments.md): Learn how to send and receive files as a Flex agent.
* [Use Chat and Messaging](/docs/flex/end-user-guide/conversations/use-chat-and-messaging.md): Learn about using chat and messaging in Flex UI 2.x.x for agents and supervisors.
* [Work with messaging transfers](/docs/flex/end-user-guide/conversations/work-with-messaging-transfers.md): Learn how to transfer a message from a Conversations channel to another agent or to a queue.
* [View customer profiles with Unified Profiles (Public Beta)](/docs/flex/end-user-guide/copilot/customerprofiles.md): View details about a customer that help you tailor your conversation to their needs.
* [Agent Copilot and Unified Profiles overview for agents (public beta)](/docs/flex/end-user-guide/copilot.md): Agent Copilot and Unified Profiles provide information and automations that enable you to assist customers more effectively.
* [Use Agent Copilot for suggested responses and answers (public beta)](/docs/flex/end-user-guide/copilot/real-time-assist-features.md): Learn how to use Agent Copilot for suggested responses and answers to enhance productivity and customer interactions.
* [Use auto-generated notes with Agent Copilot (Public Beta)](/docs/flex/end-user-guide/copilot/wrapupnotes.md): This guide describes the Agent Copilot agent experience
* [Debugger Integration with Flex](/docs/flex/end-user-guide/debugger.md): Learn how to use the debugger to troubleshoot exceptions and errors in the Twilio Flex UI and plugins.
* [Use the Flex Dialpad](/docs/flex/end-user-guide/dialpad-use.md): Use the native Flex Dialpad to make local and international outbound calls and perform warm or cold transfers to an agent or a queue.
* [Compose an email](/docs/flex/end-user-guide/email/compose-email.md): When handling an email task, you can use the HTML editor to apply formatting to your message for the customer.
* [Email-specific reporting from Flex Insights](/docs/flex/end-user-guide/email/flex-insights-reporting.md): As a supervisor, see email-related metrics and include data for email-specific reports in Flex through real-time and historical Flex Insights reporting.
* [Initiate an email conversation](/docs/flex/end-user-guide/email/initiate-email.md): You can initiate an email thread from an inbound task or initiate an email task from the Flex Agent UI.
* [Handle an email task](/docs/flex/end-user-guide/email/task.md): Accept, read and reply to an inbound email: Inbound email tasks come in like any other task for any other Task Channel. When an email arrives, the task appears at the top of the Task list.
* [View an email](/docs/flex/end-user-guide/email/view-email.md): When a customer sends an email in HTML format, you'll see the content of the email as you would expect in the Flex UI. An HTML email can contain links, images, tables, and symbols, such as emojis.
* [Use Flex on a mobile device (public beta)](/docs/flex/end-user-guide/flex-mobile.md): Flex Mobile lets agents send and receive calls and messages from a phone or tablet.
* [Initial Audio Device Check](/docs/flex/end-user-guide/initial-audio-device-check.md): Learn about the audio device health check that is automatically run on Flex startup.
* [Track Abandoned Conversations in Flex Insights](/docs/flex/end-user-guide/insights/abandoned-conversations.md): Manage and analyze abandoned conversations with Flex Insights.
* [Flex Insights Assessment Reporting](/docs/flex/end-user-guide/insights/assessment-reporting.md): Learn about the metrics and attributes used to build robust reports and dashboards on top of customer feedback with Twilio Flex Insights.
* [Best Practices and Performance Limits for Flex Insights](/docs/flex/end-user-guide/insights/best-practices-and-performance-limits.md): Read our recommended settings for fine-tuning your reports and dashboards in Flex Insights.
* [Conversation Assessment](/docs/flex/end-user-guide/insights/conversation-assessments.md): Get up and running with Twilio Flex Insights assessments by learning how to create questionnaires to assess the quality of agent calls with your customers.
* [Conversation Screen](/docs/flex/end-user-guide/insights/conversation-screen.md): Access and analyze customer conversation details with Flex Insights. Listen to call segments, view transcripts, add comments, make assessments, and more.
* [Conversation Structure](/docs/flex/end-user-guide/insights/conversation-structure.md): Understand how voice conversations are split into segments and how handling time is calculated in Flex Insights.
* [Customer Geolocation in Flex Insights](/docs/flex/end-user-guide/insights/customer-geolocation.md): Leverage geolocation of customers for insightful data and to detect location-based issues. Improve accuracy by evaluating geolocation data with Flex Insights.
* [Flex Insights Analyze View](/docs/flex/end-user-guide/insights/dashboards/analyze.md): Learn about the Twilio Flex Insights Analyze tab, an environment for data discovery and visualization in your contact center reports.
* [Dashboards](/docs/flex/end-user-guide/insights/dashboards.md): Explore the Analytics Portal's features: create dashboards, manage visibility, interact with data, and send reports seamlessly via email.
* [Rollup Summary in Tables](/docs/flex/end-user-guide/insights/dashboards/rollup-summary-tables.md): Learn how to use Flex Insights' rollup summary to create intelligent aggregation in your reports.
* [Flex Insights Data Model Caveats](/docs/flex/end-user-guide/insights/data-model-caveats.md): The Flex Insights Data Model was designed for ease of use and maximum query performance. There are a few things to be aware of when working with measures and attributes.
* [Flex Insights Data Model](/docs/flex/end-user-guide/insights/data-model.md): A thorough overview of the attributes in the Flex data model's key data sets, designed for the analytical needs of your contact center.
* [Format Metrics in Flex Insights Reports](/docs/flex/end-user-guide/insights/format-report-metrics.md): Learn how to format numerical metrics in your Flex Insights reports.
* [Getting Started with Flex Insights](/docs/flex/end-user-guide/insights/getting-started.md): Learn how to enable access, customize event collection, optimize performance, and understand data retention in Flex Insights.
* [Flex Insights](/docs/flex/end-user-guide/insights.md): Learn the basics of Twilio Flex Insights, out-of-the-box custom data views that let you drill down from top-level KPIs to individual conversation segments.
* [Flex Insights KPI Dashboards](/docs/flex/end-user-guide/insights/kpi-dashboards.md): Learn more about Twilio Flex Insights KPI dashboards, which contain Key Performance Indicators (KPIs) and insights about your business.
* [Flex Insights Maintenance and Updates](/docs/flex/end-user-guide/insights/maintenance-and-updates.md): Flex Insights has timed maintenance and update windows. Get the maintenance schedule and impact on your custom content in this guide.
* [Agent Copilot metrics](/docs/flex/end-user-guide/insights/metrics/agent-copilot.md): Learn about the custom metrics available to collect data about customer sentiment during an interaction.
* [Hold Time Metric](/docs/flex/end-user-guide/insights/metrics/hold-time.md): Explore Hold Time, a metric that shows the total time that a customer spent on hold in that segment. Find out more about how this metric is calculated and how to build reports that include it.
* [Flex Insights Metrics](/docs/flex/end-user-guide/insights/metrics.md): Explore Flex Insights Historical Reporting for integrated metrics in report and dashboard building.
* [SLA Metrics](/docs/flex/end-user-guide/insights/metrics/sla.md): Learn how to configure SLA Metrics and pass information via TaskRouter attributes with Flex Insights Historical Reporting.
* [Messaging transfer metrics](/docs/flex/end-user-guide/insights/metrics/transfer.md): Learn about the custom metrics available to collect data when an agent transfers a Flex Conversations message.
* [Play Calls](/docs/flex/end-user-guide/insights/player.md): Learn how to navigate the Flex Insights Player to get a quick overview of a call
* [Flex Insights Quality Management](/docs/flex/end-user-guide/insights/questionnaires.md): Learn how to assess the quality of your customer conversations in Twilio Flex Insights.
* [Schedule Flex Insights Dashboards with Email](/docs/flex/end-user-guide/insights/schedule-dashboards-with-email.md): Make sure that you're keeping everyone in the know about your Flex Insights data by sending regularly-updated dashboards via email. Learn how in this guide.
* [Conversation Segment Kinds](/docs/flex/end-user-guide/insights/segments.md): Learn how to distinguish between segment types in Flex Insights with the Kind attribute.
* [Workload Reporting](/docs/flex/end-user-guide/insights/workload-reporting.md): Use Flex Insights Workload Reporting to get granular information about agent activity in a given day. 
* [Keyboard Shortcuts](/docs/flex/end-user-guide/keyboard-shortcuts.md): Flex UI 2.1 includes a keyboard shortcuts menu for the most common contact center agent operations.
* [Use Chat and Messaging](/docs/flex/end-user-guide/messaging.md): Understand how to use chat and messaging in Flex UI 1.x.x as an agent and as a supervisor.
* [Pre-Release Features - End User Guide](/docs/flex/end-user-guide/pre-release-features.md): Explore Twilio's beta products available in the Pre-Release Features Page on Flex. Enable, disable, and test beta features.
* [Monitor agent activity](/docs/flex/end-user-guide/real-time-reporting/monitor-agent-activity.md): Learn how supervisors and administrators can monitor communications in real-time using Twilio Flex
* [Queues stats monitoring in Flex](/docs/flex/end-user-guide/real-time-reporting/real-time-queues-view.md): This guide for call center operators covers the Flex Real-Time Queues View, which displays metrics for inbound tasks.
* [Service Level Preferences](/docs/flex/end-user-guide/service-level-preferences.md): Use Service Level Preferences to customize how metrics in the Real-Time Queues View are calculated.
* [Advanced Team view filters](/docs/flex/end-user-guide/team-view-filters.md): Discover Team view filters, enabling more focused supervision in contact centers. 
* [User Guide to Troubleshooting the Flex UI](/docs/flex/end-user-guide/troubleshooting.md): Troubleshoot Flex UI errors using the Status Report for detailed logs, understand error types and where they appear, and learn about the Flex UI degraded mode.
* [Warm transfer](/docs/flex/end-user-guide/warm-transfer.md): This guide for call center operators explains how warm transfer works using a Flex call center.
* [Flex Mobile (public beta)](/docs/flex/flex-mobile.md): Flex Mobile is a pre-built app available for iOS and Android devices that brings the Flex experience to your phone or tablet.
* [End-of-life for Flex UI versions](/docs/flex/flex-ui-eol-reference.md): Reference Flex UI end-of-life (EOL) dates by version, learn how to turn on automatic minor updates, and keep your Flex UI on a supported version.
* [How we release Flex](/docs/flex/how-we-release-flex.md): Explore Twilio Flex platform changes, release strategies, and feature deployment. Understand version release frequency and feature updates.
* [Flex](/docs/flex.md): Find the documentation, sample code, and developer tools needed to build and tailor a contact center to your unique needs with Flex.
* [Glossary of Common Flex Terms](/docs/flex/onboarding-guide/common-flex-glossary.md): Define common Twilio Flex terms such as Task, TaskRouter, TaskQueue, Workers, and Workflow, and map them to standard contact center terminology.
* [Configure Skill-Based Routing](/docs/flex/onboarding-guide/configure-skill-based-routing.md): Set up skill-based routing in Twilio Flex by creating Skills, assigning Agents, and building TaskRouter Task Queues and Workflows to route Tasks.
* [Edit and Deploy an IVR with Twilio Studio to Route Calls to Queues](/docs/flex/onboarding-guide/edit-and-deploy-an-ivr.md): Build and deploy an Interactive Voice Response (IVR) in Twilio Studio that routes Flex calls to the right TaskRouter Queue based on caller input.
* [Explore the Built-In Flex UI Views](/docs/flex/onboarding-guide/explore-the-built-in-flex-ui-views.md): Learn the four built-in Twilio Flex UI views: the Admin Dashboard, Agent Desktop, Teams, and Queues, and what each view does and which roles can access them.
* [Handle Incoming Voice and SMS Tasks](/docs/flex/onboarding-guide/handle-incoming-voice-and-sms-tasks.md): Learn how to handle incoming voice calls and SMS messages as a Twilio Flex Agent, set your Agent status, accept Tasks, and enable outbound calling.
* [Set up your Flex account](/docs/flex/onboarding-guide/set-up-your-flex-account.md): Create your Twilio Flex account and learn about the Administrator, Supervisor, and Agent user roles you can assign to users in your Flex contact center.
* [Twilio Flex Quickstart: Getting Started with Flex Plugin Development](/docs/flex/quickstart/getting-started-plugin.md): We enhance a Twilio Flex hosted contact center with a basic React plugin. See step-by-step process and code, and how to upload assets to Twilio.
* [Flex Plugins CLI release notes](/docs/flex/release-notes/flex-plugins-cli-release-notes.md): Find out what's been added, changed, and fixed in the latest version of the Flex Plugins CLI.
* [Flex UI 2.x.x release notes](/docs/flex/release-notes/flex-ui-release-notes-for-v2xx.md): Find out what's been added, changed, and fixed in the latest version of Flex UI version 2.x.x, as well as past 2.x.x releases.
* [Flex Webchat release notes](/docs/flex/release-notes/webchat-ui-release-notes.md): Explore the latest release notes for Flex Webchat, including updates to dependencies.

## General Usage

* [Anti-Fraud Developer's Guide](/docs/usage/anti-fraud-developer-guide.md): Learn how to build applications that prevent bad actors from compromising your app, including best practices, fraud scenarios, and anti-fraud practices.
* [REST API: Addresses](/docs/usage/api/address.md): An Address instance resource represents your or your customer's physical
  location within a country.
* [REST API: Applications](/docs/usage/api/applications.md): Full API reference for the Application Resource (also called a "TwiML App") in Twilio's Voice REST API.
* [Twilio API overview](/docs/usage/api.md): Learn how to authenticate your requests to the Twilio APIs, what content type to use for API requests, and how the Twilio APIs handle webhooks.
* [REST API: Usage Records](/docs/usage/api/usage-record.md): REST API resources for retrieving usage by your Twilio account during any period, by any usage category.
* [REST API: UsageTrigger](/docs/usage/api/usage-trigger.md): Full API reference for the UsageTrigger resource in the Twilio API. Learn how to create, fetch (get), read (list), and update Usage Triggers for your account.
* [Billing Groups](/docs/usage/billing/billing-group.md): Learn how to use Twilio Billing Groups to consolidate billing across multiple accounts, locate your Billing Group ID, and retrieve usage data with the Usage API.
* [Billing](/docs/usage/billing.md): Manage your Twilio billing, including Billing Groups for consolidated invoicing, shared pricing, and unified payment methods across multiple accounts.
* [Day Resource](/docs/usage/bulkexport/day.md): A full reference for the Day Resource of the BulkExport API and code samples for how to fetch an exported day file and a list of exported days.
* [Export Custom Job Resource](/docs/usage/bulkexport/export-custom-job.md): API reference for the Export Custom Job Resource. Custom Jobs allow you to create exports for any date range.
* [ExportConfiguration resource](/docs/usage/bulkexport/exportconfiguration.md): Full API reference for the ExportConfiguration resource in the BulkExport API. Learn how to fetch (get) and update (post) an ExportConfiguration resource
* [Bulk Export API overview](/docs/usage/bulkexport.md): An overview of the BulkExport API, which helps you retrieve all of your activity logs from Twilio's platform on an ongoing or one-off basis.
* [Job Resource](/docs/usage/bulkexport/job.md): Full API reference for the Job resource in the BulkExport API. Learn how to fetch (get) and delete a Job.
* [Analyze: Investigate](/docs/usage/fraud-response-guide/analyze.md): Learn how to investigate fraud events on your Twilio account by reviewing log sources including Monitor Events, messaging logs, call logs, error codes, and Verify logs.
* [Contain: Immediate Countermeasures](/docs/usage/fraud-response-guide/contain.md): Learn how to contain fraud on your Twilio account with immediate countermeasures including Auth Token rotation, API key deletion, 2FA enablement, geo permission restrictions, and subaccount suspension.
* [Diagnose: Root Cause Analysis (RCA)](/docs/usage/fraud-response-guide/diagnose.md): Learn how to perform a Root Cause Analysis (RCA) to identify and resolve fraud incidents on your Twilio account.
* [Engage: Contact Twilio Support](/docs/usage/fraud-response-guide/engage.md): Learn when and how to contact Twilio Support during a fraud incident, including account suspension reasons, reactivation steps, and general assistance options.
* [Example: RCA Summary Request Form](/docs/usage/fraud-response-guide/example-rca-summary-request-form.md): See an example of a completed Root Cause Analysis (RCA) summary request form for reporting and resolving fraud incidents on your Twilio account.
* [Fraud & Abuse Response Guide](/docs/usage/fraud-response-guide.md): Learn how to quickly identify, contain, and remediate fraud or abuse on your Twilio account with this practical phase-based incident response guide.
* [Validate: Is this actually fraud?](/docs/usage/fraud-response-guide/validate.md): Learn how to identify and distinguish between different types of fraud activity on your Twilio account, including SMS pumping, toll fraud, account takeover, vishing, and smishing.
* [Global Safe List](/docs/usage/global-safe-list.md): Full API reference for Twilio's Global Safe List API. Sample code shows how to add and check a phone number on the Safe List.
* [General Usage](/docs/usage.md): Learn how to use Twilio's REST API, manage accounts, set up your dev environment, and protect your accounts, applications, and users against fraud.
* [Manage unused resources](/docs/usage/manage-unused-resources.md): Learn to manage unused resources on your Twilio account to optimize usage and reduce costs for Messaging Services and Programmable Voice.
* [Monitor REST API: Alerts](/docs/usage/monitor-alert.md): An Alert instance resource represents a single log entry for an error or warning encountered when Twilio makes a webhook request to your server.
* [Monitor Events resource](/docs/usage/monitor-events.md): The Events resource provides comprehensive event-logging and change-tracking for Twilio resources, with an API to retrieve your event log.
* [API mutation and conflict resolution](/docs/usage/mutation-and-conflict-resolution.md): Discover how Twilio's ETag and If-Match headers ensure data integrity with optimistic concurrency, resolving conflicts efficiently and safely.
* [Twilio API requests](/docs/usage/requests-to-twilio.md): Explore the basics of HTTP requests. Learn how to authorize your account, create or update API resources, and understand Twilio's responses.
* [API best practices](/docs/usage/rest-api-best-practices.md): Secure your Twilio API integration with best practices on encryption, access control, rate limits, and more.
* [Secure your Twilio Credentials](/docs/usage/secure-credentials.md): Keep your Twilio credentials secure by storing them in environment variables on macOS, Linux, Windows, and cloud providers, then loading them in your app code.
* [Availability and Reliability](/docs/usage/security/availability-reliability.md): Configure Fallback URLs on Twilio phone numbers to keep your voice and messaging applications available when your primary web server fails.
* [Security](/docs/usage/security.md): Twilio protects communications between Twilio and your web application with encryption. Learn how to authenticate, report vulnerabilities, and detect fraud
* [ISO/IEC Certification](/docs/usage/security/iso-iec-certification.md): Learn how Twilio's certified compliance with ISO/IEC 27001 standards assures your protection.
* [Twilio trial account](/docs/usage/trials.md): Explore the Twilio trial experience. Learn about product-specific free units, trial restrictions, 30-day expiration, and post-upgrade free units (PUFU).
* [Try out Twilio Email](/docs/usage/trials/try-out-email.md): Start building with a Twilio email trial account. Send and receive your first emails within a few minutes.
* [Try out Twilio SMS Messaging](/docs/usage/trials/try-out-sms.md): Start building with a Twilio trial account. Send and receive your first SMS messages within a few minutes.
* [Try out Twilio Voice](/docs/usage/trials/try-out-voice.md): Start building with a Twilio trial account. Make and receive your first voice calls within a few minutes.
* [Try out Twilio WhatsApp Messaging](/docs/usage/trials/try-out-whatsapp.md): Start building with a Twilio trial account. Send and receive your first WhatsApp messages within a few minutes.
* [Alarms](/docs/usage/troubleshooting/alarms.md): Learn how to configure and manage Error Log Alarms in the Twilio Console.
* [Debugging Events Webhook](/docs/usage/troubleshooting/debugging-event-webhooks.md): Learn about how you can use the Console Debugger webhook to solve errors, what its callback parameters are, and what its payload contains.
* [Twilio Debugger](/docs/usage/troubleshooting/debugging-your-application.md): Troubleshoot issues with Twilio APIs, webhooks, and more with the Twilio Debugger.
* [A Beginner's Guide to the Command Line](/docs/usage/tutorials/a-beginners-guide-to-the-command-line.md): Learn all about shells, files, directories, arguments, and useful commands in this beginner's guide to the Command Line. Includes a sample script to send SMS. 
* [How To Make REST API Requests in PowerShell](/docs/usage/tutorials/how-to-make-http-basic-request-twilio-powershell.md): We'll show Powershell's Invoke-WebRequest making a REST API request to an HTTP Basic Authentication protected endpoint to send an outbound SMS text message.
* [Secure your C# / ASP.NET app by validating incoming Twilio requests](/docs/usage/tutorials/how-to-secure-your-csharp-aspnet-app-by-validating-incoming-twilio-requests.md): Secure the actions in your C# / ASP.NET application which accepts incoming requests from Twilio. Use the Twilio C# SDK's request validator utility to confirm incoming requests to your views genuinely originated from Twilio.
* [Secure your C# / ASP.NET Core app by validating incoming Twilio requests](/docs/usage/tutorials/how-to-secure-your-csharp-aspnet-core-app-by-validating-incoming-twilio-requests.md): Secure the actions in your C# / ASP.NET Core application which accepts incoming requests from Twilio. Use the Twilio C# SDK's request validator utility to confirm incoming requests to your views genuinely originated from Twilio.
* [Secure your Express app by validating incoming Twilio requests](/docs/usage/tutorials/how-to-secure-your-express-app-by-validating-incoming-twilio-requests.md): Secure the views in your Express application which accepts incoming requests from Twilio. Use the Twilio Node SDK's webhook middleware to confirm incoming requests to your views genuinely originated from Twilio.
* [Secure your Flask app by validating incoming Twilio requests](/docs/usage/tutorials/how-to-secure-your-flask-app-by-validating-incoming-twilio-requests.md): Secure the views in your Flask application which accept incoming requests from Twilio. Use the Twilio Python SDK's request validator utility to confirm incoming requests to your views genuinely originated from Twilio.
* [Set up your C# and ASP.NET MVC development environment](/docs/usage/tutorials/how-to-set-up-your-csharp-and-asp-net-mvc-development-environment.md): Learn how to set up C# for web development using the ASP.NET Core MVC web app framework. Expose your local development machine to the Internet with ngrok.
* [Set up your Java development environment](/docs/usage/tutorials/how-to-set-up-your-java-development-environment.md): Get your local Java development environment ready-to-go starting with installing a Java distribution, then a build tool, then a Twilio app. 
* [Set up your Node.js and Express development environment](/docs/usage/tutorials/how-to-set-up-your-node-js-and-express-development-environment.md): Learn how to set up Node.js for web development using the Express web app framework. Manage dependencies with npm and use ngrok to expose your dev server.
* [Set up your PHP development environment](/docs/usage/tutorials/how-to-set-up-your-php-development-environment.md): Learn how to set up PHP for web development using vanilla PHP. Manage dependencies with Composer and expose your local development machine to the Internet with ngrok.
* [Set up your Python and Flask development environment](/docs/usage/tutorials/how-to-set-up-your-python-and-flask-development-environment.md): Guide to setting up Python for web development with the Flask web framework. Use pip   to manage packages, virtual environments for isolation, and ngrok to publish.  
* [Get started with your Twilio free trial account](/docs/usage/tutorials/how-to-use-your-free-trial-account.md): Start building with a Twilio trial account. Verify phone numbers, get a Twilio phone number, and learn about trial account restrictions and limitations.
* [How to use ngrok with Windows and Visual Studio to test webhooks](/docs/usage/tutorials/how-use-ngrok-windows-and-visual-studio-test-webhooks.md): Learn how to use ngrok with Visual Studio and IIS Express on Windows to expose your local ASP.NET app and test Twilio webhooks from a public URL.
* [Twilio API responses](/docs/usage/twilios-response.md): Explore the various response formats, exceptions, and resources returned from Twilio to your application
* [Getting Started with Twilio Webhooks](/docs/usage/webhooks/getting-started-twilio-webhooks.md): Get started using Twilio webhooks with this step-by-step guide that tells you what you need to do to process incoming callbacks from Twilio servers.
* [Webhooks: an introduction](/docs/usage/webhooks.md): Launching point for information about Twilio webhooks, including product-specific guides, tutorials, and getting started information.
* [Messaging Webhooks](/docs/usage/webhooks/messaging-webhooks.md): Learn how to use webhooks to process events in your Twilio Programmable Messaging application. You can use Twilio webhooks to handle incoming messages as well as tracking delivery status on outbound messages.
* [Voice Webhooks](/docs/usage/webhooks/voice-webhooks.md): Learn how to work with webhooks from Twilio Programmable Voice to process events in your web application. Set your project up to receive HTTPS callbacks from Twilio when important events occur, such as an inbound voice call to your Twilio phone number.
* [Webhooks (HTTP callbacks): Connection Overrides](/docs/usage/webhooks/webhooks-connection-overrides.md): Use connection overrides to customize Twilio webhook HTTP callback settings per request, including timeouts, retries, retry policy, SNI, and edge location.
* [Webhooks FAQ](/docs/usage/webhooks/webhooks-faq.md): Commonly asked questions about Twilio webhooks and status callbacks, including what webhooks are, how to validate webhooks, and how to respond to webhooks.
* [Webhooks Overview](/docs/usage/webhooks/webhooks-overview.md): Overview of the various webhooks that Twilio can send to web applications, including what webhooks are, and how you can respond to them.
* [Webhooks security](/docs/usage/webhooks/webhooks-security.md): Learn how to secure your web application that uses Twilio webhooks by verifying the sender of the webhook. This guide also covers other common security practices for Twilio webhooks, such as HTTPS and authentication.
* [Twilio Workbench](/docs/usage/workbench.md): Use Workbench to access Debugger or Alarms functionality from anywhere in the Twilio Console.

## Global Infrastructure

* [Make an outbound phone call using REST API in a non-US Twilio Region](/docs/global-infrastructure/create-an-outbound-call-via-rest-api-in-a-non-us-twilio-region.md): Follow this quickstart to learn how to initiate a call using Twilio's Ireland (IE1) Region.
* [Edge Locations](/docs/global-infrastructure/edge-locations.md): Reference list of all Twilio Edge Location IDs for public internet and private Interconnect connections.
* [Legacy Edge Location IDs](/docs/global-infrastructure/edge-locations/legacy-regions.md): Mapping of deprecated Twilio edge location IDs (au1, ie1, us2, etc.) to current Edge Location names (sydney, dublin, umatilla, etc.)
* [Firewall Configurations](/docs/global-infrastructure/firewall-configurations.md): Find firewall configuration information for Twilio Voice traffic
* [Media Streams Configuration](/docs/global-infrastructure/firewall-configurations/media-streams-configuration.md): Firewall configuration information for Voice Media Streams traffic
* [Inbound Call Processing](/docs/global-infrastructure/inbound-call-processing.md): Learn how to select the processing and storage Region for inbound calls
* [Set a phone number's inbound processing Region using the REST API](/docs/global-infrastructure/inbound-processing-api.md): Learn how to control the Region used for processing inbound calls using the Twilio REST API.
* [Set a phone number's inbound processing Region using the Console](/docs/global-infrastructure/inbound-processing-console.md): Learn how to control the Region used for processing inbound calls using the Twilio Console.
* [Global Infrastructure](/docs/global-infrastructure.md): Optimize your application performance and control data residency using Twilio Edge Locations and Regions.
* [Twilio Elastic SIP Trunking Regional Migration Best Practices](/docs/global-infrastructure/localized-uris/elastic-sip-trunk-regional-migration-best-practices.md): Learn best practices for migrating your Elastic SIP Trunks to a new Twilio Region.
* [General Twilio Voice Regional Migration Best Practices](/docs/global-infrastructure/localized-uris/regional-migration-best-practices.md): Learn best practices for migrating your Voice solutions to a new Twilio Region.
* [Twilio Programmable Voice SIP Domains Regional Migration Best Practices](/docs/global-infrastructure/localized-uris/sip-domains-regional-migration-best-practices.md): Learn best practices for migrating your Programmable Voice SIP Domains to a new Twilio Region.
* [SIP URIs](/docs/global-infrastructure/localized-uris/sip-uris.md): List of public SIP URI domains for each Twilio Edge Location
* [Termination](/docs/global-infrastructure/localized-uris/termination.md): List of public SIP Trunk Termination URI domains for each Twilio Edge Location
* [Manage Regional API Credentials](/docs/global-infrastructure/manage-regional-api-credentials.md): Manage Region-specific Twilio API credentials. Find, create, and delete Auth Tokens and API Keys for a Twilio Region using the Console, CLI, or REST API.
* [Managing Regional Resources in Console](/docs/global-infrastructure/managing-regional-resources-in-console.md): Learn to manage Region-specific resources using Twilio Console.
* [Use the Programmable Messaging API with Twilio Regions](/docs/global-infrastructure/messaging-api-with-twilio-regions.md): Learn how to use Programmable Messaging API in Twilio's Ireland (IE1) Region for SMS data residency.
* [Messaging features in Ireland (IE1)](/docs/global-infrastructure/messaging-eu-feature-availability.md): Available Messaging features in Twilio's Ireland (IE1) Region for SMS data residency.
* [Migrate SMS from US1 to IE1](/docs/global-infrastructure/migrate-sms-us1-to-ie1.md): Migrate an active Twilio SMS implementation from the United States (US1) region to the Ireland (IE1) region for EU data residency with minimal downtime.
* [Migrating your application to a new Region](/docs/global-infrastructure/migrating-your-application-to-a-new-region.md): Learn how to migrate your existing Twilio-powered application to a new Twilio Region.
* [Regional product availability](/docs/global-infrastructure/regional-product-and-feature-availability.md): These products and features are available in Twilio Regions around the world.
* [Regional SIP Domains](/docs/global-infrastructure/regional-sip-domains.md): Learn how to control which Region is used for processing and storage of your Twilio SIP Domain traffic.
* [Regional SIP Trunks](/docs/global-infrastructure/regional-sip-trunks.md): Learn how to control which Region is used for processing and storage of your Twilio Elastic SIP Trunking traffic.
* [SMS Data Residency in EU](/docs/global-infrastructure/sms-eu-data-residency.md): Learn how personal data is processed and stored in Twilio's Ireland (IE1) Region for EU data residency.
* [Understanding Edge Locations](/docs/global-infrastructure/understanding-edge-locations.md): Learn how Twilio Edge Locations route traffic to Twilio Regions, how to select an edge for Voice, SIP, and Interconnect, and how the REST API hostname sets your processing region.
* [Twilio Regions](/docs/global-infrastructure/understanding-twilio-regions.md): Learn about the data centers around the world where Twilio performs processing and storage.
* [Use the Programmable Voice JavaScript SDK with a non-US Twilio Region](/docs/global-infrastructure/use-the-programmable-voice-javascript-sdk-with-a-non-us-twilio-region.md): Learn to integrate your Twilio Voice-powered web application with our Australia (AU1) Region.
* [Using the Twilio REST API in a non-US Region](/docs/global-infrastructure/using-the-twilio-rest-api-in-a-non-us-region.md): Learn how to use the Twilio REST API in the Region of your choice.

## Glossary

* [Ad exchange](/docs/glossary/ad-exchange.md): \*Advertising\*. A digital marketplace where advertisers and publishers can buy and sell display, video, and mobile advertising.
* [Ad impression](/docs/glossary/ad-impression.md): \*Advertising\*. One occurence of an advertisement displaying on a screen.
* [Ad unit](/docs/glossary/ad-unit.md): \*Advertising\*. The container that holds the advertising copy and graphics for a digital advertisement on a screen.
* [Affiliate marketing](/docs/glossary/affiliate-marketing.md): \*Marketing\*. An activity in which companies offer to pay individuals or other businesses to promote their products or services.
* [Affirmative consent](/docs/glossary/affirmative-consent.md): \*Reputation\*. The informed, explicit acceptance that a recipient granted you to receive your email.
* [Allowlist](/docs/glossary/allow-list.md): \*Internet Security\*. A curated selection of domains, email addresses, or IP addresses that a service or system has granted explicit access.
* [Automated email](/docs/glossary/automated-email.md): \*Marketing\*. A system that allows the sending of messages with content relevant to individual recipients.
* [Autoresponder](/docs/glossary/autoresponder.md): \*Marketing\*. A system that generates email responses to actions and events.
* [Bayesian filter](/docs/glossary/bayesian-filter.md): \*Email Deliverability\*. A statistical technique that detects email spam.
* [Blocklist](/docs/glossary/blocklist.md): \*Email Deliverability\*. A list of IP addresses, email addresses, or domains known to ISPs or list providers for sending unsolicited or unwanted emails.
* [Blocked email messages](/docs/glossary/blocks.md): \*Email Deliverability\*. A temporary rejection of messages sent from your IP address.
* [Bounced email messages](/docs/glossary/bounces.md): \*Email Deliverability\*. A permanent rejection of messages sent from your IP address.
* [Bulk email service](/docs/glossary/bulk-email-service.md): \*Marketing\*. Software or service through which one sender can send one or many email messages to a large list of recipients.
* [What is Call Whisper?](/docs/glossary/call-whisper.md): Call Whisper, also commonly referred to as Call Screening, involves playing a message to the callee while the caller continues to hear ringing. It can provide additional information such as the source or purpose of the call to the callee before the call begins and even allow the callee to accept or reject the call based on that information.
* [Campaigns](/docs/glossary/campaigns.md): \*Marketing\*. The act of sending customized email messages to a group of targeted recipient segments.
* [CAN-SPAM Act of 2003](/docs/glossary/can-spam.md): \*Regulation\*. US law that lists the guidelines, requirements, and penalties regarding the sending of commercial bulk email.
* [Canonicalization](/docs/glossary/canonicalization.md): \*Internet standard\*. The standardization of email messages formatting that enables consistent hashed values for validating email messages.
* [Canadian Anti-Spam Law of 2014](/docs/glossary/casl.md): \*Regulation\*. Canadian law that lists the guidelines, requirements, and penalties regarding the sending of commercial bulk email.
* [Categories](/docs/glossary/categories.md): \*Analytics\*. One or more topical tags applied to an email message that aids in analyzing email campaign effectiveness. 
* [Content delivery network](/docs/glossary/cdn.md): \*Service Provider\*. A global network of servers that stores and serves copies of website content to website visitors using the server geographically closest to each website visitor. 
* [Challenge-response spam filtering](/docs/glossary/challenge-response.md): \*Internet Security\*. A type of spam filter that replies with a challenge to the given sender.
* [Clicks and unique clicks](/docs/glossary/clicks.md): \*Analytics\*. A record of each time a customer clicks any link in your Twilio Email email messages.
* [Canonical Name record (CNAME)](/docs/glossary/cname.md): \*Internet standard\*. A DNS record that maps one hostname in a domain to another hostname instead of an IP address.
* [Complaint](/docs/glossary/complaint.md): \*Reputation\*. A record of an email recipient reporting an email message as spam.
* [CPS](/docs/glossary/cps.md): CPS (calls per second) is the rate at which Twilio executes outbound calls for an account. 
* [Click-through rate](/docs/glossary/ctr.md): \*Analytics\*. A metric of interest in content linked in an email message expressed as a percentage of recipients that click a link in your email message.
* [Custom fields](/docs/glossary/custom-fields.md): \*Configuration\*. Original contact attribute added to your email contacts.
* [Deferral](/docs/glossary/deferrals.md): \*Email Deliverability\*. A deferred status can occur when an ISP or mailbox provider can't accept email from your IP address.
* [Deliverability](/docs/glossary/deliverability.md): \*Email Deliverability\*. The measure of how many emails sent that reach their intended recipients without issue.
* [Delivery](/docs/glossary/deliveries.md): \*Email Deliverability\*. A confirmation that an end recipient received the email that the sender had sent.
* [Demand-side platform (DSP)](/docs/glossary/demand-side-platform.md): \*Advertising\*. Software that helps advertisers or ad agencies buy digital ad inventory across publishers, supply-side platforms, and ad exchanges.
* [Direct response advertising](/docs/glossary/direct-response-advertising.md): \*Advertising\*. An advertising tactic where ad content encourages or prompts viewers of an ad to act or to engage with the ad directly.
* [DomainKeys Identified Mail (DKIM)](/docs/glossary/dkim.md): \*Internet standard\*. A domain-based email authentication protocol that helps ISPs better identify legitimate email senders.
* [Domain-based Message Authentication, Reporting and Conformance (DMARC)](/docs/glossary/dmarc.md): \*Internet Security\*, \*Internet Standard\*. A domain-based policy for determining the authenticity of the person or service sending email on behalf of a domain.
* [Domain Name System](/docs/glossary/dns.md): \*Internet standard\*. A hierarchical system of software and systems that translate a fully qualified domain name into an IP address.
* [Domain authentication](/docs/glossary/domain-authentication.md): \*Internet Security\*. Protocols and policies that specify IP addresses and domains as proof of identity of an individual or organization sending email messages.
* [Domain](/docs/glossary/domain.md): \*Internet standard\*. A human-readable branding for an individual or organization's presence on the internet.
* [Drip campaign](/docs/glossary/drip-campaign.md): \*Marketing\*. An email marketing strategy that sends engagement email messages on a schedule.
* [Drops](/docs/glossary/drops.md): \*Email Deliverability\*. The removal of an email message to a specific recipient to protect the sender's reputation.
* [Email API integration](/docs/glossary/email-api-integration.md): \*API\*. The facilitation of automating key functions through the synchronization of a sender's email service provider with their platform and software tools.
* [Email Authentication](/docs/glossary/email-authentication.md): \*Internet Security\*. Technical standards to help ISPs and other receivers validate the identity of an email sender.
* [Email harvesting](/docs/glossary/email-harvesting.md): \*Reputation\*. The process of obtaining lists of valid email addresses other than affirmative consent of the recipients for the purpose of sending bulk email.
* [Email marketing](/docs/glossary/email-marketing.md): \*Marketing\*. The promotion of a commercial product or service conveyed in an email message.
* [Email reputation score](/docs/glossary/email-reputation-score.md): \*Reputation\*. The rating an internet service provider or inbox provider sets for email sent from your email server IP addresses.
* [Email service provider (ESP)](/docs/glossary/email-service-provider.md): \*Service Provider\*. A service organization that provides transactional and marketing email services.
* [Expandable Banner](/docs/glossary/expandable-banner.md): \*Advertising\*. A design of a digital advertisement that increases in size when a viewer clicks or hovers over the ad.
* [Expired](/docs/glossary/expired.md): \*Email Deliverability\*. The removal of recipient email address from a contact list when an SMTP server couldn't deliver an email message to the recipient within 72 hours.
* [Feedback loop](/docs/glossary/feedback-loop.md): \*Reputation\*. A process where an service provider forwards emails reported as spam to a sender for removal.
* [Flighting](/docs/glossary/flighting-in-advertising.md): \*Advertising\*. The time in which an advertising campaign runs.
* [Fully Qualified Domain Name (FQDN)](/docs/glossary/fqdn.md): \*Internet standard\*. A human-readable label that identifies a specific server on the internet.
* [Frequency capping](/docs/glossary/frequency-capping.md): \*Advertising\*. The setting of a maximum number of times a specific viewer sees a specific ad. 
* [General Data Protection Regulation of 2018](/docs/glossary/gdpr.md): \*Regulation\*. European Union law that regulates the handling of personal data and outlines the rights individuals have regarding their data.
* [Header](/docs/glossary/header.md): \*Internet standard\*. Metadata that informs email recipients and servers of the routing, formatting, and security of an email message.
* [Internet Message Access Protocol (IMAP)](/docs/glossary/imap.md): \*Internet standard\*. The communication rules that systems follow to let you read and retrieve email messages from your inbox provider.
* [Glossary](/docs/glossary.md): A repository of the technical terms and jargon intrepid Twilio developers may encounter on their building journey.
* [Invalid Email](/docs/glossary/invalid-email.md): \*Email Deliverability\*. The removal of recipient email address that doesn't conform to the \[Internet Engineering Task Force (IETF)]\(https://www.ietf.org/) email address syntax standards from a contact list.
* [IP Address](/docs/glossary/ip-address.md): \*Internet standard\*. A unique numerical address that identifies a virtual location on the internet.
* [IP address warmup](/docs/glossary/ip-warmup.md): \*Email Deliverability\*. The establishment of a reputation as a legitimate email sender through the gradual and regular increase in the volume of email sent from one IP address.
* [Link branding](/docs/glossary/link-branding.md): \*Marketing\*. Change the domain for open and click tracking links to your domain.
* [Lists](/docs/glossary/lists.md): \*Marketing\*. Static collections of contacts to whom email messages can be sent.
* [Mail merge](/docs/glossary/mail-merge.md): \*Marketing\*. A process that generates customized email messages from a generic template and store of contact data.
* [Mailbox provider](/docs/glossary/mailbox-provider.md): \*Marketing\*. A service organization that provides transactional email services, marketing email services, or both.
* [Twilio Email message ID](/docs/glossary/message-id.md): \*Marketing\*. A unique identifier that Twilio Email generates and assigns to an email message for event identification purposes.
* [Mail Transfer Agent (MTA)](/docs/glossary/mta.md): \*Internet standard\*. A system that transfers email messages from one computer to another using a client-server application architecture.
* [Mail User Agent (MUA)](/docs/glossary/mua.md): \*Internet standard\*. An app that you use to compose and send email messages.
* [Mail Exchanger record (MX)](/docs/glossary/mx-record.md): \*Internet standard\*. A DNS record that maps the hostname in a domain that accepts email for the domain.
* [Native advertising](/docs/glossary/native-advertising.md): \*Advertising\*. A type of advertising that resembles the content of the surrounding medium.
* [What are North American Area Codes?](/docs/glossary/north-american-area-codes.md): North American Area Codes prefix phone numbers to route calls under the North American Numbering Plan (NANP), covering the US, Canada, US territories, and some Caribbean countries.
* [Open Rate](/docs/glossary/open-rate.md): \*Analytics\*. The frequency by which your customers open emails that you send.
* [Open relay](/docs/glossary/openrelay.md): \*Internet Security\*. An unsecured SMTP relay that routes email between domains.
* [Open & Unique Open](/docs/glossary/opens.md): \*Analytics\*. The record of each time a customer opens your Twilio Email email messages.
* [Peer-initiated invitations campaign](/docs/glossary/peer-invitations.md): \*Marketing\*. A email marketing campaign designed to get customers to invite their friends and family.
* [Phishing](/docs/glossary/phishing.md): \*Internet Security\*. The act of masquerading as a trusted business to acquire personally identifiable information.
* [Preheader](/docs/glossary/preheader.md): \*Marketing\*. The short summary text that follows the subject line when you view an email in your inbox.
* [Programmatic media buying](/docs/glossary/programmatic-media-buying.md): \*Advertising\*. Process of buying paid media through sophisticated software that automates how the buying, placing, and optimizing of paid media.
* [Pointer record (PTR)](/docs/glossary/ptr.md): \*Internet standard\*. A DNS record that maps an IP address to one hostname in a domain.
* [Rate limiting](/docs/glossary/rate-limiting.md): \*Email Deliverability\*. See Throttling.
* [Reconfirmation email](/docs/glossary/reconfirmation.md): \*Reputation\*. An email message sent to existing recipients asking them to confirm that they still want your messages.
* [Request](/docs/glossary/request.md): \*Analytics\*. The record of an attempt to send an email through Twilio Email.
* [Reseller email account](/docs/glossary/reseller-email-account.md): \*Service Provider\*. Email account created after a company entered into a partnership with Twilio.
* [Reserved fields](/docs/glossary/reserved-fields.md): \*Configuration\*. Predefined and protected attributes provided for email contacts.
* [Reverse DNS](/docs/glossary/reverse-dns.md): \*Internet Standard\*. Method for systems to resolve an IP address from a domain name.
* [Scheduled Emails](/docs/glossary/scheduled-emails.md): \*Marketing\*. Configuring a system to send email messages starting at a given date and time.
* [Segmentation](/docs/glossary/segmentation.md): \*Marketing\*. The practice of channeling email traffic based on the intent and audience of email messages.
* [Segments](/docs/glossary/segments.md): \*Marketing\*. A dynamic collection of contacts grouped based on criteria you define.
* [Sender authentication](/docs/glossary/sender-authentication.md): \*Internet Security\*. The process that shows ISPs you gave your mailbox provider permission to send emails on your behalf.
* [Sender ID](/docs/glossary/sender-id.md): \*Internet Security\*. A deprecated email authentication standard that checked that a domain authorized a given email address to send on its behalf.
* [Senders](/docs/glossary/senders.md): Identity of the individual, position, or organization sending an email message.
* [Sends](/docs/glossary/sends.md): \*Analytics\*. A request for Twilio Email to deliver email to your recipients.
* [Single send](/docs/glossary/single-send.md): \*Marketing\*. A non-recurring email message that communicates non-automated, non-sequential content.
* [SIP INVITEs](/docs/glossary/sip-invites.md): A SIP INVITE is a SIP request message that initiates a SIP call. 
   
  A SIP INVITE is made up of lines of text. The first line in an INVITE is called a Request-Line, which is followed by more lines of text called headers. The headers contain information about the INVITE, such as the identity of the caller, whether the INVITE was forwarded before being sent to the recipient, and the number of times a call may be forwarded. 
* [SMTP Provider](/docs/glossary/smtp-provider.md): \*Service Provider\*. A vendor that helps send large quantities of email messages to recipients.
* [SMTP relay](/docs/glossary/smtp-relay.md): \*Internet standard\*. A system that sends email between SMTP servers on different domains.
* [SMTP Server](/docs/glossary/smtp-server.md): \*Internet standard\*. An app or server that sends email and reacts to response codes from receiving servers.
* [SMTP service](/docs/glossary/smtp-service.md): \*Email Deliverability\*. Third-party managed service that delivers email messages to a large audience.
* [Simple Mail Transfer Protocol (SMTP)](/docs/glossary/smtp.md): \*Internet standard\*. The communication rules that systems follow for the reliable and efficient transfer of email messages.
* [Spam Filter](/docs/glossary/spam-filter.md): \*Email Deliverability\*. Algorithms that identify and remediate unwanted email messages.
* [Spam folder](/docs/glossary/spam-folder.md): \*Email Deliverability\*. A location in a recipient's inbox into which the inbox provider routes email of questionable use or provenance.
* [Spam report](/docs/glossary/spam-reports.md): \*Reputation\*. A feedback mechanism that identifies electronic messages as abusing the transmission medium and reports them to an authority for remediation.
* [Spam Traps](/docs/glossary/spam-traps.md): \*Reputation\*. Email addresses created without active owners to identify spammers and senders with poor data quality practices.
* [Spam](/docs/glossary/spam.md): \*Reputation\*. An email message sent to a recipient that they didn't request or want.
* [Sender Policy Framework (SPF)](/docs/glossary/spf.md): \*Internet Security\*, \*Internet Standard\*. An email authentication standard that sets which servers can send email from their domain.
* [Spoofing](/docs/glossary/spoofing.md): \*Internet Security\*. A technique where a falsified sender email addresses attempts to trick recipients into opening an email message.
* [Subscriber list management](/docs/glossary/subscriber-list-management.md): \*Marketing\*. The validation that subscribers found in your contact lists remain active and engaged with your email marketing.
* [Suspicious Sender](/docs/glossary/suspicious-sender.md): \*Reputation\*. An email sender who sends email messages to recipients that never granted explicit permission to that sender.
* [Reserved substitution tags](/docs/glossary/system-fields.md): \*Configuration\*. Placeholder labels that get replaced with personalized content in an email campaign.
* [Throttling](/docs/glossary/throttling.md): \*Email Deliverability\*. A recipient inbox provider reduces throughput of email messages below the level at which sender mail server sent the email messages.
* [Time zone](/docs/glossary/timezone.md): \*Internet standard\*. Local time, based on your current geographic location on the earth.
* [Transport Layer Security (TLS)](/docs/glossary/tls.md): \*Internet Security\*, \*Internet Standard\*. The set of rules that encrypts internet traffic between systems.
* [What is a Time-based One-time Password (TOTP)?](/docs/glossary/totp.md): A standardized algorithm that uses the current time as an input and generates unique numeric passwords.
* [Transactional email](/docs/glossary/transactional-email.md): \*Marketing\*. An email message sent in response to a user interaction with a web application.
* [Triggered action](/docs/glossary/triggered-actions.md): \*Marketing\*. A task executed once a customer meets a pre-defined condition.
* [Triggered email](/docs/glossary/triggered-email.md): \*Marketing\*. An email message sent in response to specific events or actions.
* [Trusted sender](/docs/glossary/trusted-sender.md): \*Reputation\*. An email sender who only sends email messages to those recipients that granted explicit permission to that sender.
* [Two Factor Authentication (2FA)](/docs/glossary/two-factor-authentication.md): \*Internet Security\*. Use of two or more means of user identification to grant access to a system.
* [Undelivered Email](/docs/glossary/undelivered-email.md): \*Email Deliverability\*. A category of reasons why an email message wasn't delivered to a recipient's inbox.
* [Unknown User](/docs/glossary/unknown-user.md): \*Email Deliverability\*. The removal of recipient email address that doesn't exist on the recipient email server from a contact list.
* [Unsubscribe](/docs/glossary/unsubscribes.md): \*Email Deliverability\*. A recipient's voluntary decision to remove themself from a sender's bulk email service.
* [Urchin Tracking Module (UTM) parameters](/docs/glossary/utm-parameters.md): \*Analytics\*. Five URL parameters added to links that marketers use to track online marketing campaigns.
* [Web API](/docs/glossary/web-api.md): A web API is a programming interface that allows web servers and web browsers to connect and enable account and data collection for services like email.
* [Application-to-Person Messaging](/docs/glossary/what-a2p-sms-application-person-messaging.md): Application-to-Person messaging (A2P) is any kind of message traffic in which a person is receiving messages from an application rather than another individual, and which is not expected to receive a reply. A2P message includes, but is not limited to, marketing communications, appointment reminders, chatbots, notifications, and one-time passwords (OTPs) or PIN codes.
* [Alphanumeric Sender ID](/docs/glossary/what-alphanumeric-sender-id.md): Your company name or brand displayed as the sender ID for one-way text messaging.
* [What are Masked Phone Numbers?](/docs/glossary/what-are-masked-phone-numbers.md): Masked Phone Numbers are a common pattern to anonymize communication between multiple parties and hide participant phone numbers. Instead of dialing directly from phone to phone, users communicate via a third ('proxy') phone number that forwards a call to the eventual destination. 
* [What are SMS Notifications?](/docs/glossary/what-are-sms-notifications.md): SMS Notifications are out-of-band text messages sent in response to events or transactions which occur somewhere else. While often used as a marketing tool to increase the percentage of returning visitors, SMS notifications are very useful for organization and public safety purposes as well.
* [What are WebSockets?](/docs/glossary/what-are-websockets.md): A WebSocket is a persistent bi-directional communication channel between a client (e.g. a browser) and a backend service. In contrast with HTTP request/response connections, websockets can transport any number of protocols and provide server-to-client message delivery without polling.
* [What is Direct Inward Dialing (DID)?](/docs/glossary/what-direct-inward-dialing-did.md): Direct Inward Dialing (DID) is a telephone service that allows a phone number to ring through directly to a specific phone at a business instead of going to a menu or a queue and needing to dial an extension. A phone number that is used like this is often called a "DID" (and multiple numbers are called "DIDs").
* [What is E.164?](/docs/glossary/what-e164.md): A numbering plan standard that provides a globally unique number for each device on the PSTN. These devices can then route phone calls and text messages to individual devices in different countries.
* [What is a Call Center?](/docs/glossary/what-is-a-call-center.md): A call center is the central point where businesses handle inbound and outbound customer phone calls. Learn how call centers differ from contact centers and the software that powers them.
* [What's an SMS Short Code?](/docs/glossary/what-is-a-short-code.md): A numeric sender ID used for text messaging containing fewer digits than typical phone numbers.
* [What is a String Identifier (SID)?](/docs/glossary/what-is-a-sid.md): A unique key string that Twilio uses to identify specific resources.
* [What is an SMS Gateway?](/docs/glossary/what-is-a-sms-gateway.md): An SMS Gateway enables a computer to send and receive SMS text messages to and from a SMS capable device over the global telecommunications network (normally to a mobile phone). The SMS Gateway translates the message sent, and makes it compatible for delivery over the network to be able to reach the recipient.
* [What is a Webhook?](/docs/glossary/what-is-a-webhook.md): An event-driven communication that sends data between apps using custom HTTP POST request to a URL.
* [Ahoy!](/docs/glossary/what-is-ahoy.md): Ahoy, a signal word originally used to call a ship, was once a standard way to greet others and was Alexander Graham Bell's suggested greeting for answering the telephone.
* [API Key](/docs/glossary/what-is-an-api-key.md): An Application Programming Interface (API) Key is a unique identifier that is used to authenticate a developer or program to an API.
* [API](/docs/glossary/what-is-an-api.md): An Application Programming Interface (API) is provided by a service owner so that others may use the features and functions enabled by the service. APIs describe how a consumer will make requests of the service, and what they will receive in return.
* [What is an SMS?](/docs/glossary/what-is-an-sms-short-message-service.md): The text messaging service that telephone, internet, and mobile devices use.
* [Artificial Intelligence](/docs/glossary/what-is-artificial-intelligence.md): Artificial Intelligence (AI) is the ability of a computer to mimic human cognitive skills, such as learning and understanding.
* [Basic Authentication](/docs/glossary/what-is-basic-authentication.md): Basic Authentication is a method for an HTTP user agent (e.g., a web browser) to provide a username and password when making a request.
* [What is Call Routing?](/docs/glossary/what-is-call-routing.md): Call routing refers to the procedure of sending voice calls to a specific queue based on predetermined criteria. A call routing system is also known as an automatic call distributor (ACD).
* [What is Call Transcription?](/docs/glossary/what-is-call-transcription.md): Call transcription is the conversion of a voice or video call audio track into written words to be stored as plain text in a conversational language. Call transcription can either be live - as a call or event happens - or based on the recording of a past conversation.
* [What is Click-to-Call?](/docs/glossary/what-is-click-to-call.md): Click-to-call, sometimes called click-to-talk or click-to-dial, is a way to let people connect with a company representative by phone while they're browsing a website or in an app.
* [What are DTMF Tones?](/docs/glossary/what-is-dtmf.md): DTMF, or Dual-Tone Multi-Frequency tones, are in-band telecommunications signals sent over voice frequencies.  Commonly used over telephone lines, DTMF tones are also commonly called Touch Tones.
* [What is GSM-7 character encoding?](/docs/glossary/what-is-gsm-7-character-encoding.md): The original assignment of 128 alphanumeric characters accepted and displayed in text messages to numerical values for transmission across mobile networks.
* [Interactive Voice Response (IVR)](/docs/glossary/what-is-ivr.md): Interactive voice response (IVR), also known as a phone tree, provides an automated telephony system for callers using voice and touch-tones (DTMF).
* [What is Latency?](/docs/glossary/what-is-latency.md): Latency is the time delay between the initiation of an event and its perception by some observer. In networking and telecommunications, latency is the time between a sender causing a change in a system's state and its reception by an observer. Network latency is often informally used interchangeably with lag.
* [What is Live Chat?](/docs/glossary/what-is-live-chat.md): Live chat is a type of online chat distinguished by its simplicity and user accessibility. Live chat appears in a web browser or in mobile applications, usually via a small pop-up modal through which the visitor can exchange text messages with a chat operator in real time.
* [Masked Calling](/docs/glossary/what-is-masked-calling.md): Masked Calling is a technique used in ecommerce to protect buyers' and sellers' personal phone numbers. Each party gets a temporary number, allowing them to communicate for a specified time period. When the time period expires, the numbers are recycled and reassigned to other parties on the platform. This prevents transactions from happening outside the platform. 
* [What is a Mean Opinion Score (MOS)?](/docs/glossary/what-is-mean-opinion-score-mos.md): A Mean Opinion Score (MOS) is a numerical measure of the human-judged overall quality of an event or experience.  In telecommunications, a Mean Opinion Score is a ranking of the quality of voice and video sessions.
  Most often judged on a scale of 1 (bad) to 5 (excellent), Mean Opinion Scores are the average of a number of other human-scored individual parameters.  Although originally Mean Opinion Scores were derived from surveys of expert observers, today a MOS is often produced by an Objective Measurement Method approximating a human ranking.
* [What is an MMS?](/docs/glossary/what-is-mms.md): MMS, short for Multimedia Messaging Service, is a standard way to send multimedia such as pictures, videos, and other attachments over text messaging channels.
* [What is a Private Branch Exchange (PBX)?](/docs/glossary/what-is-pbx-private-branch-exchange.md): PBX, short for Private Branch Exchange, is a phone system in an enterprise that manages incoming and outgoing phone calls as well as an organization's internal communications.
* [What is Personally Identifiable Information (PII)?](/docs/glossary/what-is-personally-identifiable-information-pii.md): Any data of a degree of specificity that it can locate, identify, or contact a single person. This data includes phone numbers, national ID numbers, and email addresses. It covers any data that can be used, either on its own or with combined with other data, to contact, identify, or locate a person.
* [What is a Push Notification?](/docs/glossary/what-is-push-notification.md): When an app server delivers an alert separate from an end user request, that alert is called a push notification. Also known as a server push notification or push, these alerts target mobile devices but can also target web apps.
* [What is Session Initiation Protocol (SIP)?](/docs/glossary/what-is-session-initiation-protocol-sip.md): Session Initiation Protocol (SIP) is a signalling protocol for initiating, terminating, and modifying user sessions over an IP network.  Most commonly, SIP is used for Voice Over IP (VoIP) services, but is also often used for other communications sessions such as video calls and instant messaging sessions.
* [What is SIP Trunking?](/docs/glossary/what-is-sip-trunking.md): What is SIP Calling?
  SIP (Session Initiation Protocol) trunking refers to phone calls that are routed over the Internet rather than traditional phone lines. SIP calling, therefore, refers to the act of placing calls via a SIP trunk. Because SIP calls take place across the Internet, they tend to be cheaper and more efficient than calls placed through traditional phone systems.
  Physical connections to a phone company are eliminated with the use of a SIP trunk. Using SIP trunks, a SIP provider can connect multiple channels to your private branch exchange (Voice-over-IP (VoIP) infrastructure.
* [What is an SMS API?](/docs/glossary/what-is-sms-api-short-messaging-service.md): A SMS API is well-defined software interface which enables code to send SMS Gateway.
  As the infrastructures for SMS communications and the internet are mostly divided, SMS APIs are often used to 'bridge the gap' between telecommunications carrier networks and the wider web.  SMS APIs are used to allow web applications to send and receive text messages through logic written for standard web frameworks.
* [What is SMS Delivery or Deliverability?](/docs/glossary/what-is-sms-delivery-deliverability.md): SMS Delivery is a measure of the percentage of outgoing SMS and MMS messages which are received at their intended destination.  While sometimes referring to the status of a single message, SMS delivery usually is a rate of delivered versus intended messages and summarized as an 'SMS Delivery Rate.'
* [What is SMS Pumping Fraud?](/docs/glossary/what-is-sms-pumping-fraud.md): SMS pumping fraud happens when fraudsters take advantage of a phone number input field to receive a one-time passcode, an app download link, or anything else via SMS. The messages are sent to a range of numbers controlled by a specific mobile network operator (MNO) and the fraudsters get a share of the generated revenue. 
* [What is the Telephone Consumer Protection Act (TCPA)?](/docs/glossary/what-is-telephone-consumer-protection-act-tcpa.md): The TCPA (Telephone Consumer Protection Act) is a federal statute enacted in 1991 designed to safeguard consumer privacy. This legislation restricts telemarketing communications via voice calls, SMS texts, and fax.
* [What is Toll Fraud?](/docs/glossary/what-is-toll-fraud.md): Toll fraud, also known as International Revenue Sharing Fraud (IRSF), happens when an application is exploited to generate a high volume of voice calls to the fraudster's own international premium rate numbers. The victim of the toll fraud bears the entire financial responsibility for each minute of the call.
* [What is the Twilio Markup Language (TwiML)?](/docs/glossary/what-is-twilio-markup-language-twiml.md): TwiML, or the Twilio Markup Language, is an XML based language which instructs Twilio on how to handle various events such as incoming and outgoing calls, SMS messages and MMS messages.  When building a Twilio application you will use TwiML when communicating your desired actions to Twilio.
* [What is Two Factor Authentication?](/docs/glossary/what-is-two-factor-authentication-2fa.md): Two-factor authentication (commonly abbreviated 2FA) adds an extra layer of security to your user's account login by requiring two types of authentication. This is usually something your user knows and something they have.
* [What is UCS-2 Character Encoding?](/docs/glossary/what-is-ucs-2-character-encoding.md): UCS-2 is a character encoding standard in which characters are represented by a fixed-length 16 bits (2 bytes).  It is used as a fallback on many GSM networks when a message cannot be encoded using GSM-7 or when a language requires more than 128 characters to be rendered.
* [What is Unicode?](/docs/glossary/what-is-unicode.md): Unicode is an international character encoding standard that provides a unique number for every character across languages and scripts, making almost all characters accessible across platforms, programs, and devices.
* [What is a Voice API?](/docs/glossary/what-is-voice-api.md): A PSTN) and applications connected to the internet. By using a voice API, software developers can program voice calling into their applications without specialized telecommunications knowledge and hardware.
* [What is VoIP (Voice Over IP)?](/docs/glossary/what-is-voip.md): Voice Over Internet Protocol (VoIP) is a category of hardware and software that enables voice calls to be made and received over the internet.
* [What is a Long Code?](/docs/glossary/what-long-code-phone-number.md): A long code number is a standard phone number used to send and receive voice calls and SMS messages. Phone numbers are typically called "long codes" (10-digit numbers in many countries) when comparing them with SMS short codes (5-6 digit numbers).
* [How long can a message be?](/docs/glossary/what-sms-character-limit.md): The number of characters that a service can transmit varies according to the service protocol and character encoding.
* [What is an SMS tracker?](/docs/glossary/what-sms-tracker.md): An SMS tracker is software that uncovers detailed information about the delivery and content of text and picture messages. It allows anyone to analyze an individual message or group of messages to see delivery patterns, encoding details, and error conditions.
   
* [What is UTF-8?](/docs/glossary/what-utf-8.md): UTF-8 is a variable-width character encoding standard that uses between one and four eight-bit bytes to represent all valid Unicode code points.
* [What is a Virtual Phone Number?](/docs/glossary/what-virtual-phone-number.md): A virtual phone number is a standard telephone number that is not locked down to a specific phone. A virtual number can route a voice call or text message to any phone or workflow. With virtual numbers powered by an API, complex software workflows can be built that are triggered by calls and texts.
* [What is Voice Trace?](/docs/glossary/what-voice-trace.md): Voice trace is a voice quality troubleshooting feature that captures the media stream for calls and stores them for Twilio Support to use in their investigations. 

## Identity and Access Management (IAM)

* [Access Control](/docs/iam/access-control/overview.md): This document describes the new Enhanced RBAC capabilities supported by Twilio and the introduction of new granular roles.
* [RBAC in Legacy Console](/docs/iam/access-control/rbac-legacy-console.md): Learn how to manage role assignments in the Legacy Console.
* [RBAC in Twilio Console](/docs/iam/access-control/rbac-twilio-console.md): This document describes how users can manage Role Assignments in Twilio Console
* [Role Assignment API reference](/docs/iam/access-control/role-assignment-resource.md): Complete API reference for the Twilio Role Assignment API. Learn how to list, create, and delete role assignments using OAuth 2.0.
* [Role API reference](/docs/iam/access-control/role-resource.md): Complete API reference for the Twilio Role API. Learn how to list available roles for your organization using OAuth 2.0.
* [Types of Roles](/docs/iam/access-control/types-of-roles.md): This document describes the different types of roles which are available for user assignment. It has the details of the New RBAC roles, general roles and organization roles. 
* [Access Tokens](/docs/iam/access-tokens.md): Create short-lived Access Tokens to authenticate Twilio client-side SDKs like Voice, Conversations, and Video.
* [API keys overview](/docs/iam/api-keys.md): Authenticate your requests to Twilio's APIs with API keys. Keep your Twilio Account credentials safe and take control of the lifecycle of your API keys.
* [REST API: Key Resource v1](/docs/iam/api-keys/key-resource-v1.md): Full API reference for the Key resource in the Twilio API. Learn how to create, fetch, list, update, and delete API keys.
* [REST API: Key Resource v2010](/docs/iam/api-keys/key-resource-v2010.md): Full API reference for the API Key resource in the Twilio API. Learn how to create, fetch (get), read (list), and update API keys to authenticate to the REST API and create and revoke access tokens.
* [Create API keys in Twilio Console](/docs/iam/api-keys/keys-in-console.md): Authenticate your requests to Twilio's APIs with API keys. Create and manage API keys in Twilio Console.
* [Restricted API keys](/docs/iam/api-keys/restricted-api-keys.md): Leverage role-based access control (RBAC) with Twilio's Restricted API keys. Grant granular API permissions for Twilio APIs.
* [REST API: Accounts](/docs/iam/api/account.md): Full API reference for the Account resource in the Twilio API. Learn how to create, fetch (get), read (list), and update Accounts and Subaccounts.
* [REST API: Auth Token](/docs/iam/api/authtoken.md): Learn about the REST API Auth Token, its properties, and how to promote the secondary Auth Token to primary.
* [Our API: the basics](/docs/iam/api.md): Twilio's REST API allows you to query metadata about your account, make phone calls, send text messages, and monitor usage.
* [REST API: Secondary Auth Token](/docs/iam/api/secondary_authtoken.md): Full API reference for the Account resource in the Twilio API. Learn how to create, fetch (get), read (list), and update Accounts and Subaccounts.
* [REST API: Subaccounts](/docs/iam/api/subaccounts.md): Explore how to use Twilio Subaccounts to segment your Twilio usage and act on behalf of your customers, agents or employees
* [REST API: Authorized Connect Apps](/docs/iam/authorized-connect-apps/api.md): API reference for the AuthorizedConnectApps list resource which shows all of the Connect Apps that you have authorized for your account.
* [REST API: Connect Apps](/docs/iam/connect-apps/api.md): API reference for the ConnectApps list resource.
* [Twilio Connect](/docs/iam/connect.md): Let your users authorize access to their accounts with Twilio Connect so your application can buy phone numbers, make calls, send SMS, and access log data.
* [Twilio Connect Java Quickstart](/docs/iam/connect/quickstart/java.md): Learn how to connect your application to Twilio's APIs on behalf of other account holders in this step-by-step quickstart using Java servlets.
* [Twilio Connect Python Quickstart](/docs/iam/connect/quickstart/python.md): Learn how to connect your application to Twilio's APIs on behalf of other account holders in this step-by-step quickstart using Python and Flask.
* [Credentials PublicKey Resource](/docs/iam/credentialpublickey-resource.md): Full API reference for the CredentialPublicKey resource in the Twilio API. Learn how to create, fetch (get), read (list), update, and delete Public Keys for your Twilio account.
* [REST API: Credentials](/docs/iam/credentials/api.md): Learn the basics of the Credentials REST API, which allows you to upload Public Keys to Twilio and manage them.
* [Identity and Access Management (IAM)](/docs/iam.md): Learn about Identity and Access Management (IAM) in your Twilio applications: securely control access to your Twilio projects, authenticate your applications, and dig into best practices in these docs.
* [Account-level OAuth apps](/docs/iam/oauth-apps/account-oauth-apps.md): Learn how to create, manage, and rotate secrets for account-level OAuth apps in Twilio. Account OAuth apps use the OAuth 2.0 Client Credentials grant type.
* [OAuth apps FAQs](/docs/iam/oauth-apps/faqs.md): This document describes the Frequently Asked Questions (FAQs) related to OAuth apps.
* [OAuth Token API](/docs/iam/oauth-apps/oauth-access-token.md): This document describes how to use Token API endpoint to generate Access Tokens. It also covers example of how to call Messaging API using the access token.
* [Organization OAuth apps](/docs/iam/oauth-apps/org-oauth-apps.md): Learn how to create and manage organization-level OAuth apps in Twilio. Organization OAuth apps support both the OAuth 2.0 Client Credentials and Authorization Code grant types.
* [OAuth apps](/docs/iam/oauth-apps/overview.md): Learn how to use OAuth apps to authorize access to Twilio APIs with OAuth 2.0. Supports the Client Credentials and Authorization Code grant types.
* [Domains](/docs/iam/organizations/domains.md): Learn how to associate your organization with one or more internet domains that you own. Follow instructions to add a domain or import users that signed up with your domain.
* [Organizations](/docs/iam/organizations.md): An organization is a resource that helps you manage all of your company's Twilio accounts. Learn how to centrally manage all of your accounts, users, and configure your organization-wide policies.
* [Managed accounts](/docs/iam/organizations/managed-accounts.md): Learn about Managed Accounts, how they can help your organization, and how to create, add, and configure them.
* [Managed users](/docs/iam/organizations/managed-users.md): Learn about managed users, how they can help your organization, and how to create, view, and delete them.
* [Get Started with Public Key Client Validation](/docs/iam/pkcv.md): Public Key Client Validation helps organizations in compliance-heavy industries meet strict security requirements. Learn how to get started in this overview.
* [Public Key Client Validation Quickstart](/docs/iam/pkcv/quickstart.md): Learn how to implement Public Key Client Validation with Twilio. Includes sample cURL commands, HTTP requests, and a Java example.
* [SCIM API reference](/docs/iam/scim/api-reference.md): Complete API reference for the Twilio SCIM API, including endpoints for creating, retrieving, updating, and deactivating users.
* [Microsoft Entra ID SCIM integration](/docs/iam/scim/entra-integration.md): Learn how to configure user synchronization from Microsoft Entra ID to Twilio using SCIM provisioning.
* [Okta SCIM integration](/docs/iam/scim/okta-integration.md): Learn how to configure user synchronization from Okta to Twilio using SCIM provisioning.
* [Configuring Azure Active Directory with Twilio SSO](/docs/iam/single-sign-on/configuring-azure-active-directory-with-twilio-sso.md): Learn how to configure Azure Active Directory to work with Twilio SSO in this step-by-step guide.
* [Configuring Okta with Twilio SSO](/docs/iam/single-sign-on/configuring-okta-with-twilio-sso.md): Learn how to configure Okta to work with Twilio in this step-by-step guide.
* [Configuring SSO with any other SAML2.0 Identity Provider](/docs/iam/single-sign-on/configuring-sso-with-other-saml2-idp.md): This guide covers configuring your SAML 2.0 Identity Provider with Twilio for SSO login to Twilio Console.
* [Single Sign On](/docs/iam/single-sign-on.md): This document describes the SSO (single sign-on) capabilities supported by Twilio and necessary steps for integrating with your Identity Provider (IdP).
* [Test Credentials](/docs/iam/test-credentials.md): REST API resources for working with Twilio's test credentials.
* [HIPAA Accounts](/docs/iam/twilio-editions/hippa.md): Learn how to set up HIPAA-compliant communication workflows with Twilio, including eligible services, Business Associate Agreements, and architecture guidelines.
* [Twilio Editions](/docs/iam/twilio-editions.md): Learn about Twilio Editions, which offers advanced security, administration, and compliance features designed to protect your customer communications.
* [Static Proxy for Webhooks](/docs/iam/twilio-editions/twilio-static-proxy.md): Learn about Twilio Static Proxy for Event Streams, Functions, and Webhooks, including static IP addresses and ranges for allowlisting.

## Interconnect

* [Interconnect](/docs/interconnect.md): Ensure consistent connectivity between your communication infrastructure and the Twilio platform with Interconnect, a private connection to the Twilio cloud.

## Lookup

* [Lookup](/docs/lookup.md): Improve your message deliverability with Twilio Lookup. Validate numbers, identify carriers, and ensure compliance for accurate and secure messaging.
* [Lookup SIM Swap Overview](/docs/lookup/lookup-sim-swap.md): Learn how to use Twilio's Lookup API SIM Swap feature to get data on if a SIM linked to a phone number has recently changed in this overview.
* [Lookup v2 Quickstart](/docs/lookup/quickstart.md): Learn how to query phone number and carrier information with Twilio's Lookup v2 API in this Quickstart.
* [Using Lookup with Twilio Regions](/docs/lookup/using-lookup-with-twilio-regions.md): Learn how to use Twilio's Lookup API with Regional support to optimize performance and control data residency in this overview.
* [Lookup v1 Tutorial: Carrier and Caller Name](/docs/lookup/v1-api/carrier-and-caller-name.md): Learn how to use Lookup to identify a phone number's carrier and what type of phone it is in your programming language of choice.
* [Lookup v1 API](/docs/lookup/v1-api.md): Identify local-friendly number formats, reduce undelivered messages, and protect from scams and spam with Lookup by Twilio.
* [Lookup v1 Tutorial: Validation and Formatting](/docs/lookup/v1-api/validation-and-formatting.md): Instructions and sample code for using the Lookup API to check the format of an international phone number and validate any phone number in ISO format.
* [Call Forwarding](/docs/lookup/v2-api/call-forwarding.md): Check if a mobile phone number is unconditionally forwarding calls using Twilio Lookup's Call Forwarding.
* [Caller Name](/docs/lookup/v2-api/caller-name.md): Retrieve caller names and types for US mobile numbers using Twilio Lookup's Caller Name.
* [Formatting and Validation](/docs/lookup/v2-api/formatting-validation.md): Learn how to use Twilio Lookup API's Line Type Intelligence package with this reference.
* [Identity Match](/docs/lookup/v2-api/identity-match.md): Use Identity Match to verify phone number ownership by comparing user data with authoritative sources. Available in the US, Brazil, and more.
* [Lookup v2 API](/docs/lookup/v2-api.md): API reference for the Twilio Lookup API that allows you to query information on a phone number so that you can make a trusted interaction with your user.
* [Line Status](/docs/lookup/v2-api/line-status.md): Validate phone number status with Twilio Lookup's Line Status. Enhance data quality and campaign efficiency by detecting number activity.
* [Line Type Intelligence](/docs/lookup/v2-api/line-type-intelligence.md): Discover carrier data and phone line types to streamline messaging and connectivity. Ideal for filtering out landlines before sending SMS.
* [Reassigned Number](/docs/lookup/v2-api/reassigned-number.md): Verify phone number ownership with Twilio Lookup's Reassigned Number to prevent TCPA violations and ensure compliance.
* [SIM Swap](/docs/lookup/v2-api/sim-swap.md): Detect SIM swap fraud with Twilio's Lookup API. Get real-time updates on SIM changes to prevent account takeovers.
* [SMS Pumping Risk Score](/docs/lookup/v2-api/sms-pumping-risk.md): Use Twilio Lookup's SMS Pumping Risk Score to get real-time risk assessments of phone numbers and detect SMS pumping fraud before sending OTP messages.

## Marketplace

* [Marketplace](/docs/marketplace.md): Do more with less code. Twilio Marketplace lets you discover, install, and manage pre-integrated partner apps and Add-ons through the Twilio API.

## Mobile Identity APIs

* [Mobile Identity APIs](/docs/mobile-identity.md): Twilio Mobile Identity APIs, including Silent Network Auth and Identity Match, help you verify users, reduce friction, and prevent fraud and account takeovers.

## Network Traversal Service

* [REST API: Network Traversal Service Tokens](/docs/stun-turn/api.md): REST API reference for Network Traversal Service (NTS) Tokens, the ephemeral STUN/TURN credentials for WebRTC and VoIP clients.
* [Frequently Asked Questions](/docs/stun-turn/faq.md): Frequently Asked Questions and troubleshooting tips for working with Twilio's Network Traversal Service
* [Network Traversal Service](/docs/stun-turn.md): Deploy more reliable WebRTC communications applications with Twilio's Network Traversal Service, a globally distributed STUN/TURN service.
* [STUN-TURN IP Addresses & Ports](/docs/stun-turn/regions.md): List the static IP addresses for the Twilio STUN and TURN servers. This allows local network configuration and communication or application of routing rules with Twilio.

## OpenAPI

* [OpenAPI](/docs/openapi.md): Learn about building with the Twilio OpenAPI Spec.

## Phone Numbers

* [AvailablePhoneNumber Mobile resource](/docs/phone-numbers/api/availablephonenumber-mobile-resource.md): A full reference for the AvailablePhoneNumber Mobile resource with code samples to find mobile numbers by region.
* [AvailablePhoneNumber resource](/docs/phone-numbers/api/availablephonenumber-resource.md): Full reference for the AvailablePhoneNumber resource in the Phone Numbers API, with properties and sample code showing how to find supported countries.
* [AvailablePhoneNumber TollFree resource](/docs/phone-numbers/api/availablephonenumber-tollfree-resource.md): A full API reference for the AvailablePhoneNumber TollFree resource, including code samples.
* [AvailablePhoneNumber Local resource](/docs/phone-numbers/api/availablephonenumberlocal-resource.md): Search for Twilio phone numbers available for purchase in a specific geographic location.
* [IncomingPhoneNumber resource](/docs/phone-numbers/api/incomingphonenumber-resource.md): Full API reference for the Incoming Phone Number resource in the Twilio API. Learn how to create, fetch (get), read (list), update, and delete IncomingPhoneNumbers.
* [Phone Numbers](/docs/phone-numbers/api.md): Find relevant links for working with Twilio's Phone Numbers REST API on this page.
* [Best practices for phone number use](/docs/phone-numbers/best-practices.md): Learn about best practices for using Twilio Phone Numbers, including buying, upgrading, and releasing numbers.
* [REST API: Available Numbers](/docs/phone-numbers/global-catalog/api/available-numbers.md): Learn more about the Available Numbers endpoint that provides a rich view into Twilio's inventory of phone numbers available for purchase.
* [Global Phone Numbers Catalog](/docs/phone-numbers/global-catalog.md): The Global Phone Numbers Catalog gives you access to our full suite of available phone numbers, featuring numbers tailored to specific use cases.
* [Hosted Number Order Resource](/docs/phone-numbers/hosted-numbers/hosted-numbers-api/hosted-number-order-resource.md): Full API reference for the Hosted Number Order resource in the Twilio Hosted Numbers API. Sample code shows how to create, read fetch, update, and delete.
* [Hosted Numbers FAQ](/docs/phone-numbers/hosted-numbers.md): Find answers to frequently asked questions about Hosted SMS, which lets you to use Programmable SMS with your existing US & Canada phone numbers.
* [Hosted Number Orders - API Quickstart](/docs/phone-numbers/hosted-numbers/quickstart.md): Get started with the Hosted Number Orders API and learn how to verify number ownership, create and sign an LOA, and configure your Hosted Number.
* [Phone Numbers](/docs/phone-numbers.md): Twilio's virtual phone numbers give you instant access to local, national, mobile, and toll-free phone numbers in over 100 countries for your voice call and messaging applications.
* [Pricing: Phone Numbers Resource](/docs/phone-numbers/pricing.md): Twilio's Phone Numbers resource allows users of the Pricing API to view pricing information for Twilio phone numbers in different countries and area codes.
* [Bundles Resource](/docs/phone-numbers/regulatory/api/bundles.md): Full API reference for the Twilio API Regulatory Compliance Bundle resource: create, fetch, read, and update your Bundle.
* [Regulatory Compliance REST APIs](/docs/phone-numbers/regulatory/api.md): View the resources available to be leveraged with the new v2 Regulatory Compliance platform.
* [Phone Number Regulatory FAQ](/docs/phone-numbers/regulatory/faq.md): Learn about Twilio Phone Number regulations, what you need to do to stay compliant, and why.
* [Console: Getting Started with Phone Number Regulatory Compliance](/docs/phone-numbers/regulatory/getting-started/console-create-new-bundle.md): Learn how to make sure your phone numbers are compliant with local regulators' requirements by following this step-by-step guide and the Twilio Console.
* [Getting Started: Regulatory Compliance Public REST APIs](/docs/phone-numbers/regulatory/getting-started/create-new-bundle-public-rest-apis.md): Learn how to create a Twilio Regulatory Bundle with the v2 Regulatory Compliance REST APIs by reading a Regulation and assigning End-Users and Supporting Documents.
* [How to Find a BU SID or an AD SID](/docs/phone-numbers/regulatory/getting-started/how-find-bu-sid-or-ad-sid.md): Follow this guide to find an ID for an identity document bundle (BU) or address (AD) in your account.
* [Letter of Authorization (LOA) Template](/docs/phone-numbers/regulatory/letter-authorization-loa-template.md): A templated example of a Letter of Authorization (LOA) requesting authorization for inbound customer calls made to your business' Customer Support.
* [Reading Regulations for the UK Bundle](/docs/phone-numbers/regulatory/reading-regulations-for-the-uk-bundle.md): Read the regulatory requirements for United Kingdom phone numbers using the Twilio Regulatory Compliance API. Includes parameters and example responses for the four UK use cases.

## Programmable Chat

* [Programmable Chat](/docs/chat.md): Twilio Programmable Chat API allows you to embed chat functionality in any of your apps with SDKs for iOS (Swift and Objective-C), Android (Java), and web (JavaScript).

## Programmable Messaging

* [Messaging API Overview](/docs/messaging/api.md): Use the Programmable Messaging REST API to send and receive SMS, MMS, and WhatsApp messages, track delivery status, and manage message media and history.
* [Media subresource](/docs/messaging/api/media-resource.md): Full API Reference for the Media subresource of the Programmable Messaging API. Get and manage Media related to Messages originating with MMS (SMS), WhatsApp and other Messaging Channels.
* [Feedback subresource](/docs/messaging/api/message-feedback-resource.md): API Reference for Twilio's Feedback subresource. Use Feedback to track and report SMS message delivery back to Twilio.
* [Messages resource](/docs/messaging/api/message-resource.md): API reference for the Message resource: send SMS, MMS, and WhatsApp messages, query message statuses, and get, update, or delete sent messages.
* [Services PhoneNumbers subresource](/docs/messaging/api/phonenumber-resource.md): Full API reference for sending SMS messages at scale with Twilio. Learn how to create, fetch, read, and update Phone Numbers on your Messaging Services.
* [Pricing: Messaging Countries resource](/docs/messaging/api/pricing.md): Full API reference for pricing of Twilio's Programmable Messaging API. Get pricing information for a country or list all countries with Twilio Message Resource services.
* [Services resource](/docs/messaging/api/service-resource.md): Full API reference for sending SMS or WhatsApp messages at scale with Twilio Messaging Services. Learn how to create, fetch, read, and update Messaging Services.
* [Get started with Facebook Messenger (public beta)](/docs/messaging/channels/facebook-messenger.md): Receive and respond to messages from your Facebook pages using Flex and Twilio's APIs
* [Twilio Messaging Channels](/docs/messaging/channels.md): Twilio Messaging Channels include SMS, MMS and a collection of 3rd-party integrations (WhatsApp, Facebook Messenger) to send and receive messages using the Programmable Messaging APIs and other Twilio products.
* [A2P 10DLC - Gather the Required Business Information](/docs/messaging/compliance/a2p-10dlc/collect-business-info.md): Begin the A2P 10DLC onboarding process for your business or your customers' businesses. This page covers the information needed for registration.
* [New Direct Sole Proprietor Registration Overview](</docs/messaging/compliance/a2p-10dlc/direct-sole-proprietor-registration-overview-new experience.md>): Register A2P 10DLC messaging as a Sole Proprietor Brand in the Twilio Console. Create a brand, register a campaign, and add a 10DLC phone number sender.
* [Direct Sole Proprietor Registration Overview](/docs/messaging/compliance/a2p-10dlc/direct-sole-proprietor-registration-overview.md): Register A2P 10DLC messaging as a Sole Proprietor Brand in the Twilio Console. Create a Starter Profile, register a brand and campaign, and add a 10DLC sender.
* [Direct Standard and Low-Volume Standard Registration Guide](/docs/messaging/compliance/a2p-10dlc/direct-standard-onboarding.md): A step-by-step guide for Direct customers to onboard Standard Brands to US A2P 10DLC messaging.
* [Set Up A2P 10DLC Event Streams](/docs/messaging/compliance/a2p-10dlc/event-streams-setup.md): Guide to configuring Event Streams for Twilio A2P Brands, Campaigns, and 10DLC Phone Numbers, covering both API and Console methods.
* [A2P 10DLC - Use Externally Registered Campaigns](/docs/messaging/compliance/a2p-10dlc/externally-registered-campaigns-api.md): Learn how to set up an A2P 10DLC Campaign registered directly with TCR with a Twilio Messaging Service in this guide.
* [Programmable Messaging and A2P 10DLC](/docs/messaging/compliance/a2p-10dlc.md): Start the new registration process to get a verified sender identity for A2P 10DLC. Send high volume SMS and MMS over trusted, compliant carrier routes.
* [Create Mock US A2P 10DLC Brands and Campaigns](/docs/messaging/compliance/a2p-10dlc/mock-brand-api.md): Learn how to create mock US A2P 10DLC Brands and Campaigns that allow you to develop and test applications against Twilio's A2P Brand and Campaign APIs without incurring any A2P 10DLC related fees.
* [A2P 10DLC - Registration for Government and Nonprofit Agencies](/docs/messaging/compliance/a2p-10dlc/onboarding-for-government-and-non-profit-agencies.md): Learn how to register for A2P 10DLC as a government or nonprofit agency with Twilio.
* [New Sole Proprietor A2P 10DLC Registration for ISVs: API Walkthrough](/docs/messaging/compliance/a2p-10dlc/onboarding-isv-api-sole-prop-new.md): Learn how to register customers for A2P 10DLC Sole Proprietor Brands and Campaigns as an ISV using the Twilio API.
* [A2P 10DLC - Standard and Low-Volume Standard Brand Onboarding Guide for ISVs](/docs/messaging/compliance/a2p-10dlc/onboarding-isv-api.md): Detailed REST API onboarding guide for ISVs to register their customers for A2P 10DLC. For Standard and Low-Volume Standard Brands.
* [ISV A2P 10DLC Onboarding Overview](/docs/messaging/compliance/a2p-10dlc/onboarding-isv.md): Onboarding overview for ISVs on Twilio A2P 10DLC messaging: covers registration, various Account architectures, and special cases for efficient compliance.
* [A2P 10DLC registration application quickstart](/docs/messaging/compliance/a2p-10dlc/quickstart.md): A step-by-step guide to get started quickly with US A2P 10DLC messaging.
* [Transition from a Sole Proprietor to a Standard Brand](/docs/messaging/compliance/a2p-10dlc/transition-sole-proprietor-to-standard-brand.md): A comprehensive guide on transitioning from Twilio Sole Proprietor to Standard Brand for A2P 10DLC, covering new registrations and Messaging Service options.
* [Troubleshooting A2P 10DLC Registrations](/docs/messaging/compliance/a2p-10dlc/troubleshooting-a2p-brands.md): Learn how to troubleshoot and resubmit your US A2P Brand and/or Campaign with a few API calls, or using our Console tools.
* [Troubleshooting A2P Phone Number registration issues](/docs/messaging/compliance/a2p-10dlc/troubleshooting-a2p-brands/troubleshooting-a2p-phone-number-registration-issues.md): Troubleshoot A2P 10DLC phone number registration failures after Campaign approval, including status explanations and remediation steps.
* [Troubleshooting and rectifying Campaigns](/docs/messaging/compliance/a2p-10dlc/troubleshooting-a2p-brands/troubleshooting-and-rectifying-a2p-campaigns-1.md): Troubleshoot and fix A2P 10DLC Campaign creation failures using the Twilio Console or API.
* [Troubleshooting A2P 10DLC Standard/LVS Brands](/docs/messaging/compliance/a2p-10dlc/troubleshooting-a2p-brands/troubleshooting-and-rectifying-a2p-standardlvs-brands.md): Learn how to address Brand Registration feedback from The Campaign Registry to improve your Trust Score or troubleshoot failed registrations.
* [Troubleshooting Sole Proprietor Brand Registration Failures](/docs/messaging/compliance/a2p-10dlc/troubleshooting-a2p-brands/troubleshooting-sole-proprietor-brand-registration-failures.md): Troubleshoot and resolve Sole Proprietor Brand registration failures for A2P 10DLC, including email and address validation errors.
* [Get started with toll-free verification using the API](/docs/messaging/compliance/toll-free/api-onboarding.md): Guide to verify Toll-Free numbers via Twilio API, covering submission, record management, and status updates for compliant messaging in North America.
* [Toll-free verification console onboarding guide](/docs/messaging/compliance/toll-free/console-onboarding.md): Guide on verifying Toll-Free numbers in the Twilio Console, covering steps for submission, status review, and deleting verification for U.S. messaging compliance.
* [Intelligent Alerts for Twilio Messaging](/docs/messaging/features/intelligent-alerts.md): Learn about Intelligent Alerts for Twilio Messaging. Understand how to enable and use this feature to monitor your messaging traffic.
* [Link Shortening](/docs/messaging/features/link-shortening.md): Send messages with shortened links using your own domain and track engagement with click tracking.
* [Link Shortening Onboarding Guide](/docs/messaging/features/link-shortening/onboarding-guide.md): Bring your own company-branded domain and send messages with shortened links and click tracking.
* [Message Scheduling](/docs/messaging/features/message-scheduling.md): Schedule RCS, SMS, MMS, and WhatsApp messages to be sent at a fixed time in the future.
* [Messaging Insights Dashboards](/docs/messaging/features/messaging-insights/dashboards.md): Use Twilio Messaging Insights dashboards to visualize and analyze message deliverability data, calculate cost-per-conversion for OTP, and more.
* [SMS Pumping Protection Insights](/docs/messaging/features/messaging-insights/sms-pumping-protection-insights.md): Use Twilio Messaging Intelligence to visualize SMS Pumping Protection Insights in a dashboard. Monitor the savings and performance of SMS Pumping Protection.
* [Programmable Messaging Logs](/docs/messaging/features/messaging-logs.md): Learn how to debug message delivery issues with your Message logs in the Twilio Console.
* [SMS Pumping Protection for Programmable Messaging](/docs/messaging/features/sms-pumping-protection-programmable-messaging.md): Use SMS Pumping Protection for Programmable Messaging to prevent SMS pumping fraud. Understand how to enable the protection and avoid false positives.
* [Traffic Optimization Engine](/docs/messaging/features/traffic-optimization-engine.md): Traffic Optimization Engine is a throughput allocation platform for Messaging customers to send high-speed, high-volume messages anywhere in the world.
* [Accepted content types for media](/docs/messaging/guides/accepted-mime-types.md): Learn about MIME types and size restrictions for media messages on Twilio's API. Optimize your MMS, RCS, and WhatsApp communications effectively.
* [Best Practices for Scaling with Messaging Services](/docs/messaging/guides/best-practices-at-scale.md): Best practices for scaling a Twilio Messaging application, including sender selection and calculating message throughput.
* [Debugging Common Issues with SMS](/docs/messaging/guides/debugging-common-issues.md): Debugging tips for common issues with SMS and MMS messages.
* [Test SMS messaging with the Virtual Phone](/docs/messaging/guides/guide-to-using-the-twilio-virtual-phone.md): Test SMS messages with the Twilio Virtual Phone. Send and receive texts without carrier restrictions, and explore Twilio's Messaging API hassle-free.
* [Best Practices for Messaging Delivery Status Logging](/docs/messaging/guides/outbound-message-logging.md): Best practices for logging SMS messages sent using Programmable Messaging, focusing on logging for Mobile Terminated/Outbound messaging.
* [Outbound Message Status in Status Callbacks](/docs/messaging/guides/outbound-message-status-in-status-callbacks.md): Learn for which changes in outbound message status Twilio sends status callback requests. Understand the status lifecycle from creation, through sending and delivery to read receipt. Recognize the differences when using a Messaging Service.
* [Message Redaction for Programmable Messaging](/docs/messaging/guides/privacy-message-redaction.md): Protect users' privacy with phone number and content redaction. Learn how to prevent long-term storage of a message body and phone number.
* [What to know before sending international SMS messages](/docs/messaging/guides/sending-international-sms-guide.md): Send international SMS on Twilio's API. Learn global SMS basics: country best practice, long & short code, P2P, A2P, GSM-7, UCS-2, alphanumeric sender ID.
* [SMS Geo Permissions](/docs/messaging/guides/sms-geo-permissions.md): Learn how to configure Twilio SMS Geo Permissions to control which countries you can send SMS messages to and reduce your exposure to SMS pumping fraud.
* [Track the Message Status of Outbound Messages](/docs/messaging/guides/track-outbound-message-status.md): Learn how to track the status of outbound messages you send with Programmable Messaging in your web application. Track the sent and delivery status of SMS, MMS, and WhatsApp Messages using status callbacks. Understand the differences when using a Messaging Service.
* [Twilio's request to your incoming message Webhook URL](/docs/messaging/guides/webhook-request.md): What does Twilio send in its request to your webhook URL? See what parameters are included for SMS, RCS, and WhatsApp-messages using Programmable Messaging.
* [Programmable Messaging](/docs/messaging.md): Everything you need to get started sending SMS and WhatsApp messages with Programmable Messaging. Quickstarts, sample code, & tutorials for many use cases. SDKs in popular web languages and examples and API Reference documentation.
* [Programmable Messaging Onboarding](/docs/messaging/onboarding.md): Learn how to plan and build your Programmable Messaging application
* [SMS Foundations](/docs/messaging/onboarding/sms-foundations.md): Learn the fundamentals of how Twilio SMS messaging works, including A2P messaging, senders, throughput, message costs, and compliance basics.
* [SMS developer quickstart](/docs/messaging/quickstart.md): This developer quickstart teaches you how to send and receive text messages with Twilio programmatically. Choose the language of your preference and start building with Twilio Programmable SMS.
* [No-code SMS quickstart with Twilio Studio](/docs/messaging/quickstart/no-code-sms-studio-quickstart.md): Learn how to use Twilio Studio to send SMS text messages without using code.
* [Alphanumeric Sender IDs in Messaging Services](/docs/messaging/services/alphanumeric-sender-ids-in-messaging-services.md): Learn how to add Alphanumeric Sender IDs to your Twilio Messaging Service Sender Pool for branded one-way SMS messaging.
* [Messaging Services](/docs/messaging/services.md): Use the Twilio Messaging Services API and Programmable Messaging to send high volumes of messages in the US and globally.
* [Customize users' opt-in and opt-out experience with Advanced Opt-Out](/docs/messaging/tutorials/advanced-opt-out.md): Customize Opt-in/Opt-out options for Twilio Programmable SMS. Localize with country-specific keywords in different languages with Twilio Advanced Opt-Out.
* [Test your SMS Application](/docs/messaging/tutorials/automate-testing.md): Learn how to send test SMS using Twilio's Programmable SMS API and test credentials
* [Receive and Download Images on Incoming Media Messages with C#](/docs/messaging/tutorials/how-to-receive-and-download-images-incoming-mms/csharp.md): Use C#, ASP.NET, and Twilio to receive and download images and other media on incoming MMS messages.
* [Receive and Download Images on Incoming Media Messages](/docs/messaging/tutorials/how-to-receive-and-download-images-incoming-mms.md): Learn how to use Twilio Programmable Messaging to receive and download images and other media on incoming MMS and media messages.
* [Receive and Download Images on Incoming Media Messages with Java](/docs/messaging/tutorials/how-to-receive-and-download-images-incoming-mms/java.md): Use Java and Twilio to receive and download images and other media on incoming MMS messages.
* [Receive and Download Images on Incoming Media Messages with Node.js](/docs/messaging/tutorials/how-to-receive-and-download-images-incoming-mms/node.md): Use Node.js and Twilio to receive and download images and other media on incoming MMS messages.
* [Receive and Download Images on Incoming Media Messages with PHP and Laravel](/docs/messaging/tutorials/how-to-receive-and-download-images-incoming-mms/php-laravel.md): Use PHP, Laravel, and Twilio to receive and download images and other media on incoming MMS messages.
* [Receive and Download Images on Incoming Media Messages with Python and Django](/docs/messaging/tutorials/how-to-receive-and-download-images-incoming-mms/python-django.md): Use Python, Django, and Twilio to receive and download images and other media on incoming MMS messages.
* [Media subresource](/docs/messaging/tutorials/how-to-receive-and-download-images-incoming-mms/ruby-sinatra.md): Full API Reference for the Media subresource of the Programmable Messaging API. Get and manage Media related to Messages originating with MMS (SMS), WhatsApp and other Messaging Channels.
* [Receive and Reply to Incoming Messages - C#](/docs/messaging/tutorials/how-to-receive-and-reply/csharp.md): Learn how to respond to an incoming message using Twilio's Programmable Messaging API and C# / ASP.NET.
* [Receive and Reply to Incoming Messages](/docs/messaging/tutorials/how-to-receive-and-reply.md): Learn how to respond to an incoming message using Twilio's Programmable Messaging API
* [Receive and Reply to Incoming Messages - Node.js](/docs/messaging/tutorials/how-to-receive-and-reply/node-js.md): Learn how to respond to an incoming message using Twilio's Programmable Messaging API and Node.js.
* [Receive and Reply to Incoming Messages - Python](/docs/messaging/tutorials/how-to-receive-and-reply/python.md): Learn how to respond to an incoming message using Twilio's Programmable Messaging API and Python.
* [Send SMS and MMS messages](/docs/messaging/tutorials/how-to-send-sms-messages.md): A guide to send SMS text messages and MMS messages programmatically from your application or the cURL command line utility using Twilio Programmable Messaging.
* [Get started with Messaging Services](/docs/messaging/tutorials/send-messages-with-messaging-services.md): Enhance your Messaging application with Messaging Services. Send bulk messages with short codes by using multiple numbers and improve message delivery.
* [TwiML™ for Programmable Messaging](/docs/messaging/twiml.md): Learn how Twilio uses the TwiML markup language to talk to your Programmable SMS applications.
* [TwiML™ Message: \<Message>](/docs/messaging/twiml/message.md): Follow sample code to learn how to programmatically send a message to a phone number with the \<Message> verb for Programmable Messaging.

## Programmable Voice

* [Answering Machine Detection FAQ & Best Practices](/docs/voice/answering-machine-detection-faq-best-practices.md): FAQs and best practices for optimizing Twilio Answering Machine Detection for Programmable Voice notifications, outbound contact centers, and sales dialers.
* [Answering Machine Detection](/docs/voice/answering-machine-detection.md): Use Twilio Answering Machine Detection (AMD) for voice notifications, outbound contact centers, AI agents, and sales dialers using REST API calls.
* [Events subresource](/docs/voice/api/call-event-resource.md): Full Twilio Voice API reference for the Call Events subresource used to review and analyze application request and response details.
* [Call resource](/docs/voice/api/call-resource.md): Reference for the Twilio Programmable Voice Call resource, detailing the REST API for initiating, managing, and retrieving records of voice calls.
* [Conferences Participants subresource](/docs/voice/api/conference-participant-resource.md): Full API reference for the Conferences Participants subresource in the Twilio API. Learn how to manage active conference participants.
* [Conferences resource](/docs/voice/api/conference-resource.md): Full reference for the Twilio Voice API Conferences resource. Programmatically update and retrieve data from active conference calls.
* [Programmable Voice API Overview](/docs/voice/api.md): Introduction to the Twilio Voice REST API. Use this API to make phone calls, modify calls in progress, and query metadata about calls, conferences, queues, and recordings.
* [OutgoingCallerIds resource](/docs/voice/api/outgoing-caller-ids.md): Reference API documentation for Twilio OutgoingCallerIds. Manage outgoing caller IDs and verify phone numbers with the Twilio REST API.
* [Calls Transcriptions subresource](/docs/voice/api/realtime-transcription-resource.md): Full API reference for the Calls Transcriptions subresource in the Twilio API.
* [Outbound - Receiving SIP from Twilio](/docs/voice/api/receiving-sip.md): Use Twilio Programmable Voice to initiate SIP sessions and pass custom headers or UUI for call centers and self-service automation using TwiML and REST APIs.
* [Transcriptions resource](/docs/voice/api/recording-transcription.md): Twilio Transcriptions resource reference to fetch or delete transcriptions of recorded voice calls over the Twilio REST API.
* [Recordings resource](/docs/voice/api/recording.md): Full detailed REST API reference for managing recordings with Twilio's Programmable Voice REST API.
* [Inbound - Sending SIP to Twilio](/docs/voice/api/sending-sip.md): Send SIP calls to Twilio Programmable Voice using SIP domains. Covers inbound contact center and PSTN connectivity use cases using JavaScript and Bash.
* [Use SIP with Twilio Voice](/docs/voice/api/sip-interface.md): Learn to use Twilio Programmable Voice SIP Interface to route calls to SIP endpoints for contact center, PSTN connectivity, and AI agent use cases.
* [Making SIP Calls](/docs/voice/api/sip-making-calls.md): Learn to initiate SIP VoIP sessions with Twilio Programmable Voice across coding languages for sales dialer, contact center, and tracking use cases.
* [SIP registration](/docs/voice/api/sip-registration.md): Register SIP endpoints with Twilio Programmable Voice to make and receive global calls from devices like IP phones or softphones using your SIP Domain.
* [Streams subresource](/docs/voice/api/stream-resource.md): Full Twilio API reference for the Streams subresource. Learn how to create, stop, and manage real-time WebSocket media streams on a phone call.
* [Verifying Caller IDs at Scale](/docs/voice/api/verifying-caller-ids-scale.md): Learn to programmatically verify phone numbers with Twilio Programmable Voice and Sync for outbound call center and sales dialer use cases in Node.js.
* [Brand your calls using CNAM](/docs/voice/brand-your-calls-using-cnam.md): Learn how to brand Twilio Programmable Voice calls with Caller ID Name (CNAM) for business outbound calls via Twilio Console or Trust Hub REST API.
* [Branded Calling overview](/docs/voice/branded-calling.md): Boost trust with Twilio Branded Calling by displaying your business name and logo during outbound calls to improve answer rates.
* [Bring Your Own Carrier (BYOC) Trunking for Programmable Voice](/docs/voice/bring-your-own-carrier-byoc.md): Learn how to use Twilio BYOC Trunking to connect existing PSTN carriers and phone numbers to Twilio Programmable Voice for call centers and PSTN connectivity.
* [Voice Conference](/docs/voice/conference.md): Get a high-level overview of Voice Conference, a flexible Twilio product to manage multi-party calls for inbound contact centers and outbound dialer use cases.
* [Track usage, costs, and application health for Twilio Programmable Voice](/docs/voice/guides/track-usage-costs-health.md): Learn to track Twilio Programmable Voice usage, costs, and health using the Console, Usage API, and Datadog for notifications and call tracking.
* [How to share information between your applications](/docs/voice/how-share-information-between-your-applications.md): Exchanging custom parameters between backend and frontend Twilio Programmable Voice applications using TwiML, REST APIs, and Voice SDKs.
* [Programmable Voice](/docs/voice.md): Use Twilio Programmable Voice to add inbound and outbound voice calls to your web or mobile app. Use our Voice API or SDKs for web languages. Build Interactive Voice Response, conference calling, automated surveys and more. Integrate your VoIP system with Twilio SIP. See call analytics and insights.
* [Interactive Voice Response](/docs/voice/interactive-voice-response.md): Build an Interactive Voice Response (IVR) phone tree with Twilio Programmable Voice using Node.js, Python, Ruby, C#, Java, and PHP.
* [Media Streams Overview](/docs/voice/media-streams.md): Receive raw audio streams from live phone calls over WebSockets using Twilio Media Streams for AI/ML transcription and self-service automation.
* [Media Streams - WebSocket Messages](/docs/voice/media-streams/websocket-messages.md): Learn about WebSocket Messages for Twilio Media Streams to support Inbound Contact Center, Outbound Contact Center, and AI/ML Transcription use cases.
* [Pricing: Voice Resource](/docs/voice/pricing.md): Twilio's Pricing Voice resource provides a simple API to pull real-time, account-specific pricing for Twilio's programmable voice product.
* [No-code Voice quickstart with Twilio Studio](/docs/voice/quickstart/no-code-voice-studio-quickstart.md): Learn how to use Twilio Studio to receive and respond to phone calls without using code.
* [Getting Started with the Voice Android SDK](/docs/voice/sdks/android/get-started.md): Learn how to add voice communications to your mobile applications with Twilio's Programmable Voice API in this Twilio Voice Quickstart for Android.
* [Voice Android SDK](/docs/voice/sdks/android.md): Learn how to add VoIP calling into native applications with the Twilio Programmable Voice Android SDK reference.
* [Voice SDK Error Codes](/docs/voice/sdks/error-codes.md): Explore Voice SDK error codes and find solutions for Twilio Voice issues with our comprehensive guide, covering common errors, causes, and fixes.
* [Voice SDKs](/docs/voice/sdks.md): The Twilio Programmable Voice SDKs make it easy for you to add voice-over-IP (VoIP) calling into your web and native mobile applications quickly.
* [Getting Started with the Voice iOS SDK](/docs/voice/sdks/ios/get-started.md): Learn how to get started Programmable Voice for iOS and add Voice over IP (VoIP) to your iOS application.
* [Voice iOS SDK](/docs/voice/sdks/ios.md): Learn the basics of working with the Twilio Programmable Voice SDK for iOS reference, including installation, versioning, and authentication.
* [Voice JavaScript SDK: Best Practices](/docs/voice/sdks/javascript/best-practices.md): Get the most out of the Twilio Voice JavaScript SDK by following these best practices, and ensure your users have a seamless calling experience. They will also make it easier to troubleshoot connection and call quality issues.
* [Voice JavaScript SDK: Changelog](/docs/voice/sdks/javascript/changelog.md): Changelog for the Voice JavaScript SDK including new features, bug fixes and updates.
* [Voice JavaScript SDK quickstart](/docs/voice/sdks/javascript/get-started.md): Learn how to add voice communications to your front-end applications with Twilio's Programmable Voice API in this Voice JavaScript SDK Quickstart.
* [Voice JavaScript SDK: Twilio in the browser](/docs/voice/sdks/javascript.md): Use the Voice JavaScript SDK to make and receive voice calls in web browsers. Supports Chrome, Firefox, Safari, and Edge.
* [Voice JavaScript SDK: Twilio.Call](/docs/voice/sdks/javascript/twiliocall.md): Reference documentation for Call, an API object that represents a call to or from Twilio's network, with methods, events, accessors, and sample code.
* [Twilio.Device.audio](/docs/voice/sdks/javascript/twiliodevice/device-audio.md): How to control the audio on a device on web-based calls with the Twilio Voice JavaScript SDK. Info on browser support, methods, properties, events, and more.
* [Voice JavaScript SDK: Twilio.Device](/docs/voice/sdks/javascript/twiliodevice.md): Learn how to use the Programmable Voice JavaScript SDK to facilitate connections between Twilio and audio connections.
* [Voice SDKs Network Connectivity Requirements](/docs/voice/sdks/network-connectivity-requirements.md): A Programmable Voice SDK connectivity checklist and overview, a list of our servers' ports and IP addresses, and the bandwidth required for quality audio.
* [Voice React Native SDK](/docs/voice/sdks/react-native.md): Learn the basics of working with the Programmable Voice SDK for React Native.
* [SIP](/docs/voice/sip.md): Connect your SIP infrastructure to Twilio for global reach and automation. Supports PSTN connectivity and outbound contact center use cases.
* [SIP Quickstart](/docs/voice/sip/quickstart.md): Learn to register a SIP Domain using Twilio Programmable Voice with Node.js and SIP softphones for inbound and outbound contact centers and PSTN connectivity.
* [Increase Call Answer Rates with Voice Integrity](/docs/voice/spam-monitoring-with-voiceintegrity.md): Remediate spam labels and monitor Twilio phone number reputation to increase call answer rates for voice notifications and outbound contact centers.
* [Troubleshooting voice calls](/docs/voice/troubleshooting.md): Learn how to use Twilio's debugging tools to resolve issues with voice notifications, IVRs, and contact centers using the Twilio REST API and Console.
* [Trusted calling with SHAKEN/STIR](/docs/voice/trusted-calling-with-shakenstir.md): Learn about SHAKEN/STIR verification for Twilio Programmable Voice to improve call answer rates for notifications, contact centers, and sales dialer use cases.
* [Build an Interactive Voice Response (IVR) Phone Tree](/docs/voice/tutorials/build-interactive-voice-response-ivr-phone-tree.md): Find links to step-by-step tutorials complete with sample code to learn how to build an Interactive Voice Response (IVR) phone tree in your programming language of choice.
* [IVR: Phone Tree with Python and Flask](/docs/voice/tutorials/build-interactive-voice-response-ivr-phone-tree/python.md): Learn how to create a seamless customer service experience by building an IVR Phone Tree for your company with Python, Flask and Twilio.
* [Consume a real-time Media Stream using WebSockets, Python, and Flask](/docs/voice/tutorials/consume-real-time-media-stream-using-websockets-python-and-flask.md): Stream real-time voice data with Twilio Media Streams, Python, and Flask for use cases like inbound contact centers and AI/ML transcription.
* [Emergency Calling for Programmable Voice](/docs/voice/tutorials/emergency-calling-for-programmable-voice.md): Configure Twilio Emergency Calling for US, CA, UK, and other countries to route emergency calls to PSAPs using Twilio Programmable Voice.
* [How to capture your first payment using \<Pay>](/docs/voice/tutorials/how-capture-your-first-payment-using-pay.md): Learn to capture payments using Twilio Programmable Voice \<Pay> with Stripe for voice self-service automation and automated notification use cases.
* [Create conference calls](/docs/voice/tutorials/how-to-create-conference-calls.md): Learn how to use Twilio Programmable Voice to create and manage conference calls for inbound and outbound contact centers or call tracking in Node.js, Python, C#, Java, PHP, or Ruby.
* [Gather User Input with Keypad](/docs/voice/tutorials/how-to-gather-user-input-via-keypad.md): Gather user input for Twilio Programmable Voice using DTMF tones with the \<Gather> TwiML verb for IVR, phone trees, and self-service automation.
* [Make outbound phone calls](/docs/voice/tutorials/how-to-make-outbound-phone-calls.md): Learn to make outbound phone calls with Twilio Programmable Voice across multiple coding languages for notifications, call centers, and automation.
* [Modify Calls In Progress](/docs/voice/tutorials/how-to-modify-calls-in-progress.md): Learn how to use Twilio Programmable Voice to modify live phone calls and manage call states.
* [Record Phone Calls](/docs/voice/tutorials/how-to-record-phone-calls.md): Learn to record inbound and outbound calls with Twilio Programmable Voice using Python, Node.js, PHP, C#, Java, and Ruby.
* [Respond to Incoming Phone Calls](/docs/voice/tutorials/how-to-respond-to-incoming-phone-calls.md): Respond to incoming phone calls with Twilio Programmable Voice by handling incoming webhooks with TwiML responses for voice apps and notifications.
* [Retrieve call logs](/docs/voice/tutorials/how-to-retrieve-call-logs.md): Retrieve call logs using Twilio Programmable Voice to monitor incoming and outgoing call activity, filter call records, and troubleshoot call issues.
* [How to route calls to your SIP network with an outbound call](/docs/voice/tutorials/how-to-route-calls-to-your-sip-network.md): Learn to route calls to your Twilio SIP network using Twilio Programmable Voice with API code samples for notifications and contact centers.
* [TwiML™ Voice: \<Client>](/docs/voice/twiml/client.md): Twilio TwiML Voice \<Client> reference documentation to specify a client identifier to dial using the Voice SDK device.
* [TwiML Voice: \<Conference>](/docs/voice/twiml/conference.md): Twilio TwiML Voice \<Conference> reference documentation to connect calls to a named conference room for hold, transfer, and barge.
* [TwiML™ Voice: \<Connect>](/docs/voice/twiml/connect.md): Twilio TwiML Voice \<Connect> reference documentation to connect incoming phone calls to other Twilio services or external systems.
* [TwiML™ Voice: \<Application>](/docs/voice/twiml/dial/application.md): Twilio TwiML Voice \<Application> reference documentation to connect calls to another Twilio account using a TwiML App.
* [TwiML™ Voice: \<Dial>](/docs/voice/twiml/dial.md): Twilio TwiML Voice \<Dial> reference documentation to connect a caller to another phone number, conference room, application, or SIP endpoint.
* [TwiML™ Voice: \<Enqueue>](/docs/voice/twiml/enqueue.md): Twilio TwiML Voice \<Enqueue> reference documentation to programmatically hold and queue a call until it is dequeued or transferred.
* [TwiML™ Voice: \<Gather>](/docs/voice/twiml/gather.md): Twilio TwiML Voice \<Gather> reference documentation to collect phone input via DTMF keypad tones or speech transcriptions.
* [TwiML™ Voice: \<Hangup>](/docs/voice/twiml/hangup.md): Twilio TwiML Voice \<Hangup> reference documentation to programmatically end a call.
* [TwiML™ for Programmable Voice](/docs/voice/twiml.md): Twilio TwiML for Programmable Voice reference documentation to learn how to use markup language instructions to control voice application calls.
* [TwiML™ Voice: \<Number>](/docs/voice/twiml/number.md): Twilio TwiML Voice \<Number> reference documentation to specify a phone number to dial using the \<Dial> verb.
* [TwiML™ Voice: \<Pause>](/docs/voice/twiml/pause.md): Twilio TwiML Voice \<Pause> reference documentation to programmatically introduce silent waits during a phone call.
* [Generic Pay Connector](/docs/voice/twiml/pay/generic-pay-connector.md): Reference guide for Twilio Generic Pay Connector. Learn how to securely integrate custom payment processors into voice applications.
* [TwiML™ Voice: \<Pay>](/docs/voice/twiml/pay.md): Twilio TwiML Voice \<Pay> reference documentation to securely collect credit card payment data during a phone call.
* [Pay Connectors](/docs/voice/twiml/pay/pay-connectors.md): Learn about Pay Connectors, what products support it, and how to install and configure one.
* [TwiML™ Voice: \<Play>](/docs/voice/twiml/play.md): Twilio TwiML Voice \<Play> reference documentation to play audio files or stream custom audio back to callers.
* [TwiML™ Voice: \<Queue>](/docs/voice/twiml/queue.md): Twilio TwiML Voice \<Queue> reference documentation to dial a queue and connect callers using the \<Dial> verb.
* [TwiML™ Voice: \<Record>](/docs/voice/twiml/record.md): Reference documentation for the Twilio Voice TwiML \<Record> verb to record and transcribe live audio in your applications.
* [TwiML™ Voice: \<Recording>](/docs/voice/twiml/recording.md): Reference documentation for the Twilio Voice TwiML \<Recording> noun used to start and configure call audio recordings.
* [TwiML™ Voice: \<Redirect>](/docs/voice/twiml/redirect.md): Twilio TwiML Voice \<Redirect> reference documentation. Learn how to programmatically transfer call control to a different URL.
* [TwiML™ Voice: \<Refer>](/docs/voice/twiml/refer.md): Twilio TwiML Voice \<Refer> reference documentation. Instruct Twilio to programmatically initiate a SIP transfer toward your infrastructure.
* [TwiML™ Voice: \<Say>](/docs/voice/twiml/say.md): Reference documentation for the Twilio Voice TwiML \<Say> verb to convert text-to-speech in your applications.
* [Text-to-Speech](/docs/voice/twiml/say/text-speech.md): Text-to-Speech (TTS) is a process where text is converted into a human-sounding voice. Learn more about Twilio TTS technology.
* [TwiML™ Voice: \<Sip>](/docs/voice/twiml/sip.md): Learn how to use the Twilio TwiML \<Sip> noun to programmatically set up VoIP sessions and send voice calls to any SIP endpoint in this reference guide.
* [TwiML™️ Voice: \<Stream>](/docs/voice/twiml/stream.md): Twilio TwiML Voice \<Stream> reference to learn to receive raw audio streams from a live phone call over WebSockets in near real-time.
* [TwiML™ Voice: \<Transcription>](/docs/voice/twiml/transcription.md): Twilio TwiML Voice \<Transcription> reference to transcribe live phone call audio streams in near real-time.
* [Dialogflow CX onboarding guide](/docs/voice/virtual-agent/dialogflow-cx-onboarding.md): Integrate Twilio with Google Dialogflow CX (Conversational Agents) to build AI agents and automated voice experiences for contact centers.
* [Virtual Agent](/docs/voice/virtual-agent.md): Connect Twilio Voice calls to Google Dialogflow ES or CX agents for AI agents use case.
* [Voice Insights Advanced Features](/docs/voice/voice-insights/advanced-features.md): Learn to activate Twilio Voice Insights Advanced Features for call metrics, event streams, and API access to track complex call quality use cases.
* [Details: Conversation Relay Insights Events](/docs/voice/voice-insights/api/call/details-conversation-relay-events.md): Supplementary details and explanations of Conversation Relay events in Voice Insights. Reference for event types, latency signals, and interaction markers available via the Call Insights Events API for calls using Conversation Relay.
* [Details: Voice Insights SDK Events](/docs/voice/voice-insights/api/call/details-sdk-call-quality-events.md): Supplementary details and explanations of Voice SDK events underlying Voice Insights for programmatic use with REST API, Events Streams or application code.
* [Voice Insights Event Streams](/docs/voice/voice-insights/event-streams.md): Learn to access Twilio Voice Insights Event Streams for real-time Call and Conference Insights call quality monitoring analytics and data pipelines.
* [Voice Insights](/docs/voice/voice-insights.md): Learn how to gather call and conference metrics, quality events, and metadata with Voice Insights by Twilio for analytics and call quality tracking.

## Proxy: One-to-one Masked Communications

* [The Proxy API Overview](/docs/proxy/api.md): Twilio Proxy lets you add masked conversations with two parties to your app or site. Use the REST API or SDKs to automatically associate temporary numbers, with tracking and custom timeouts. Dive into our REST API reference here.
* [Interaction](/docs/proxy/api/interaction.md): Full API reference for the Interaction resource in the Twilio Proxy REST API for masked communications.
* [Participant](/docs/proxy/api/participant.md): Full API reference for the Participant resource in the Twilio Proxy REST API for masked communications.
* [Phone Number](/docs/proxy/api/phone-number.md): Full API reference for the Phone Number resource and managing the number pool in the Twilio Proxy REST API for masked communications.
* [Sending Messages](/docs/proxy/api/sending-messages.md): Full API reference for the MessageInteraction resource in the Twilio Proxy REST API for masked communications. How to send messages to a session participant.
* [Service](/docs/proxy/api/service.md): Full API reference for the Service resource in the Twilio Proxy REST API for masked communications.
* [Session Resource](/docs/proxy/api/session.md): Full API reference for the Session resource in the Twilio Proxy REST API for masked communications.
* [Webhooks](/docs/proxy/api/webhooks.md): A reference page showing the available webhooks in the Twilio Proxy masked communications API and a list of the parameters that are passed with each webhook.
* [Using Proxy with Channels](/docs/proxy/channels.md): Learn how to configure Twilio Proxy to use multiple communication channels such as WhatsApp and Facebook Messenger in this usage guide.
* [Using Proxy with Flex A2P SMS](/docs/proxy/flex-a2p-10dlc.md): Is your contact center sending application-to-person SMS in the United States? A2P 10DLC is probably relevant to you. Read on to learn how to register your phone numbers and configure your Twilio Flex Contact Center to send registered traffic.
* [Proxy: One-to-one Masked Communications](/docs/proxy.md): Twilio Proxy lets you add masked conversations with two parties to your app or site. Use the REST API or SDKs to automatically associate temporary numbers, with tracking and custom timeouts. For services which need two-way temporary comms on Voice or SMS, it makes implementation fast.
* [Moving to Proxy Beta from Developer Preview](/docs/proxy/moving-to-beta-from-preview.md): If you are a customer who previously used the developer preview version of Proxy, you will need to update your code to use the new beta version.
* [Opt-out keywords](/docs/proxy/opt-out-keywords.md): Learn how Twilio Proxy handles opt-out and opt-in keywords and special considerations to make during implementation in this guide.
* [Out-of-Session Callback Response Guide](/docs/proxy/out-session-callback-response-guide.md): Learn how Twilio Proxy handles incoming communications from out-of-session participants with callback responses in this usage guide.
* [How many Phone Numbers do I need?](/docs/proxy/phone-numbers-needed.md): Learn how to determine how many phone numbers to have in your Twilio Proxy number pool (the Proxy service) for masked communications in your apps and websites.
* [Proxy Changelog](/docs/proxy/proxy-changelog.md): Learn more about Twilio Proxy's recent releases and updates in this Changelog.
* [Proxy Limits](/docs/proxy/proxy-limits.md): Learn about the limits of Twilio Proxy including number pool, participants, data, and throughput limits in this guide.
* [Proxy Quickstart](/docs/proxy/quickstart.md): Build masked, one-to-one communications over SMS and Voice with the Proxy quickstart. Step-by-step tutorial with code examples to set up anonymous conversations using C# and .NET, Java, Node.js, PHP, Python, and Ruby.
* [Reserved Phone Numbers](/docs/proxy/reserved-phone-numbers.md): Learn how to mark phone numbers in your pool as reserved with Twilio's Proxy API in this usage guide.
* [Phone Number Management](/docs/proxy/understanding-phone-number-management.md): We walk through how Twilio Proxy manages phone numbers and selects numbers from the number pool when creating cloaked communications channels between two people
* [Using the Reserved Numbers and Auto-Create functionalities to support the "online directory" scenarios](/docs/proxy/using-the-reserved-numbers-and-auto-create-functionalities-to-support-the-online-directory-scenarios.md): Learn how to support online directory scenarios by forwarding all out-of-session communications to a specific person with Twilio's Proxy API in this guide.

## RCS Business Messaging

* [RCS Business Messaging](/docs/rcs.md): Learn how Twilio uses RCS Business Messaging in its products to help businesses communicate with their customers.
* [Get started with branded RCS messaging](/docs/rcs/onboarding.md): Learn the setup and configuration required to send Rich Communication Services (RCS) messages with Twilio Programmable Messaging.
* [Programmable Messaging RCS Regional Availability](/docs/rcs/regional.md): Learn about the regional availability and considerations of Rich Communication Services in Twilio Programmable Messaging.
* [Send and receive RCS messages](/docs/rcs/send-an-rcs-message.md): Learn how to send and receive Rich Communication Services (RCS) messages with Twilio Programmable Messaging.

## SDKs

* [SDKs](/docs/libraries.md): Easily use Twilio APIs in the programming language of your choice. Download and install helpers for Node.js, Python, Go, PHP, iOS, Android, C#, and more.

## SMPP API

* [SMPP API](/docs/smpp.md): Enhance SMS delivery with Twilio's SMPP API, offering secure, scalable messaging solutions for global businesses.

## Serverless

* [Quickstart](/docs/serverless/api/quickstart.md): Learn the fundamentals of using the Serverless API directly. Create a Service, Environment, Function, Function Version, Build, and a Deployment.

## Studio

* [Studio](/docs/studio.md): Use Twilio Studio's low-code builder to create and manage communication workflows like SMS chatbots and order notifications.
* [New Studio engine](/docs/studio/new-studio-engine.md): Learn about the new Studio engine, how Twilio migrates existing Studio flows to it, and how to check which engine processed an execution.
* [Execution Resource](/docs/studio/rest-api/execution.md): API reference for the Execution resource in the Studio REST API. Sample code shows how to create, fetch (get), read (list), update, and delete executions.
* [Flow](/docs/studio/rest-api/flow.md): Full API reference for the Flow resource in the Studio API with code samples showing how to fetch (get), read (list), and delete a Studio Flow.
* [REST API v1](/docs/studio/rest-api.md): Overview of the REST API v1 for Studio including basic usage, authentication requirements, and SDKs.
* [Execution Context](/docs/studio/rest-api/v2/execution-context.md): API reference for the Execution Context resource of a Studio Flow. Learn how to fetch an Execution Context using the REST API for Studio.
* [Execution](/docs/studio/rest-api/v2/execution.md): API reference for the Execution resource of a Studio Flow. Learn how to create and modify an Execution using the REST API for Studio.
* [Flow](/docs/studio/rest-api/v2/flow.md): API reference for the Flow resource of a Studio Flow. Learn how to create and modify a Flow using the REST API for Studio.
* [REST API v2](/docs/studio/rest-api/v2.md): Learn the basics of triggering Studio flows programmatically with the Studio REST API.
* [Step](/docs/studio/rest-api/v2/step.md): API reference for the Step resource of a Studio Flow Execution. Learn how to fetch and list Steps of an Execution using the REST API for Studio.
* [Studio Flows API Quickstart](/docs/studio/rest-api/v2/studio-flows-api-quickstart.md): Get started with the Twilio Studio Flows REST API. Learn how to create a Flow in Console, then fetch and update its JSON definition with cURL and the API.
* [Test User](/docs/studio/rest-api/v2/test-user.md): API reference for fetching Test Users of a Studio Flow.
* [Subflows](/docs/studio/subflows.md): Overview of Subflows in Studio including basic usage, working with variables, limitations, and testing.
* [Customer Support Menu with WhatsApp and Twilio Studio](/docs/studio/tutorials/customer-support-menu.md): Build a simple customer support bot in WhatsApp using Twilio Studio. Answer common questions and take the first step to build out your WhatsApp presence!
* [Build a Chatbot with Twilio Studio](/docs/studio/tutorials/how-to-build-a-chatbot.md): Learn how to build a Chatbot with Studio, Twilio's drag-and-drop virtual workflow builder.
* [How to build an IVR with Twilio Studio](/docs/studio/tutorials/how-to-build-an-ivr.md): Create IVR systems without coding using Twilio Studio's drag-and-drop editor. Build and route calls efficiently with speech or keypress inputs.
* [Conduct an SMS Survey with Twilio Studio](/docs/studio/tutorials/how-to-conduct-a-survey.md): Build a Twilio Studio Flow that sends an SMS survey, validates replies with the Split Based On widget, and posts responses to your server via REST API.
* [Forward Calls with Twilio Studio](/docs/studio/tutorials/how-to-forward-calls.md): Set up call forwarding with just one Twilio Studio widget. Divert calls to your personal or business number and never miss a critical call again.
* [Post Messages to Slack with Twilio Studio](/docs/studio/tutorials/how-to-post-sms-to-slack.md): Post inbound SMS to a Slack feed with Twilio Studio and an incoming Slack webhook.
* [Send Appointment Reminders with Twilio Studio](/docs/studio/tutorials/how-to-send-appointment-reminders.md): Build a Twilio Studio Flow that sends SMS appointment reminders via REST API, collects confirm or cancel replies, and posts the response to your server.
* [Set up an SMS Autoresponder with Twilio Studio](/docs/studio/tutorials/how-to-set-up-auto-responder.md): Use Twilio Studio to create an autoresponder to greet incoming SMS or Whatsapp messages with a personalized response.
* [Tutorials](/docs/studio/tutorials.md): List of step-by-step tutorials demonstrating how to use Studio.
* [Use RCS messaging with Studio](/docs/studio/tutorials/use-rcs-with-studio.md): Learn how to enable RCS messaging in your Twilio Studio Flow to send and receive RCS messages.
* [Using Twilio Conversations with Studio](/docs/studio/tutorials/using-conversations-with-studio.md): Guide on how to use the Twilio Conversations integration with Studio.
* [Get Started with Twilio Studio](/docs/studio/user-guide/get-started.md): Overview of setting up a Studio application including working with widgets, Liquid variables, and troubleshooting flows.
* [Studio User Guide](/docs/studio/user-guide.md): Design, deploy and scale customer communications seamlessly with Twilio Studio. Designed for cross-functional teams, anyone can create and modify flows.
* [Liquid Template Language](/docs/studio/user-guide/liquid-template-language.md): Learn to use the Liquid Template Language to render dynamic content in Twilio Studio.
* [Studio FAQ](/docs/studio/user-guide/studio-faq.md): Frequently asked questions about Twilio Studio.
* [Studio Troubleshooting](/docs/studio/user-guide/studio-troubleshooting.md): Guide demonstrating how to use logs and revisions effectively when attempting to find problems occurring within a Flow.
* [Call Recording widget](/docs/studio/widget-library/call-recording.md): Learn how to use the Call Recording widget in your Twilio Studio flow to switch Voice Call Recording ON or OFF at any point during an incoming call flow.
* [Connect Call To widget](/docs/studio/widget-library/connect-call.md): Learn how to connect an in-progress call with another phone number, Client user, SIM, SIP endpoint, or conference with the Connect Call To widget.
* [Connect Virtual Agent widget](/docs/studio/widget-library/connect-virtual-agent.md): Learn how to connect a Twilio Voice call or Twilio Conversations to a Dialogflow CX agent using the Connect Virtual Agent widget.
* [Enqueue Call widget](/docs/studio/widget-library/enqueue-call.md): Enqueue a current call managed with Studio into a call queue with the Enqueue Call widget and play music for your caller until they are dequeued.
* [Gather Input On Call widget](/docs/studio/widget-library/gather-input-call.md): Gather a user's input while they are on a call with the Gather Input On Call widget for Studio and collect DTMF keypresses or text from speech recognition.
* [Make HTTP Request widget](/docs/studio/widget-library/http-request.md): Learn how to interact with code that lives outside of Studio with the Make HTTP Request widget to communicate between Studio and business logic.
* [Widget Library](/docs/studio/widget-library.md): Widgets are individual items that can be dragged onto the Flow canvas in Twilio Studio. They represent pieces of logic, and can connect to each other via Transitions.
* [Make Outgoing Call widget](/docs/studio/widget-library/make-outgoing-call.md): Learn how to dial a contact's phone number from within your Studio Flow with the Make Call widget.
* [Record Voicemail widget](/docs/studio/widget-library/record-voicemail.md): Record and transcribe a caller's message with the Record Voicemail widget.
* [Run Function widget](/docs/studio/widget-library/run-function.md): Execute Twilio Functions from within your Studio flow with the Run Functions widget and communicate between your flow and more complex business logic.
* [Say/Play widget](/docs/studio/widget-library/sayplay.md): Play a recorded message or dictate text to a user on call with the Say/Play widget in your Studio flow.
* [Send to Flex widget](/docs/studio/widget-library/send-flex.md): Learn how to transfer an incoming message or call to Flex with the Send to Flex widget.
* [Send Message widget](/docs/studio/widget-library/send-message.md): Send a message to a user with the Send Message widget and respond to users that message your application from an SMS or Programmable Chat channel.
* [Send and Wait For Reply widget](/docs/studio/widget-library/send-wait-reply.md): Learn how to send an outgoing message, wait for a reply, and collect the user's response with the Send and Wait For Reply widget.
* [Set Variables widget](/docs/studio/widget-library/set-variables.md): Learn how to save key/value pairs in the global context of your Studio flow with the SetVariables widget and dynamically update data as your flow executes.
* [Split Based On... widget](/docs/studio/widget-library/split-based-on.md): Learn how to split your Studio flow and connect to specific widgets based on user conditions with the Split Based On widget.
* [Trigger (Start) widget](/docs/studio/widget-library/trigger-start.md): Begin the Studio Flow with the Trigger (Start) widget and communicate between Studio and the parts of your business logic.
* [TwiML Redirect widget](/docs/studio/widget-library/twiml-redirect.md): Redirect a Voice Call to be handled outside of Studio with the TwiML Redirect widget and pass parameters to your TwiML Redirect URL.

## Sync: Shared state in the cloud

* [Sync: Shared state in the cloud](/docs/sync.md): Sync, Twilio's state synchronization service, offers two-way real-time communication between browsers, mobiles, and the cloud. Find REST API docs, tutorials, user guides, and quickstarts to get you syncing in your web and mobile apps, fast.

## TaskRouter: Skills-based routing for contact centers

* [Activity Based Routing](/docs/taskrouter/activity-based-routing.md): Use TaskRouter activity-based routing to target or exclude Workers based on their Activity state, so you can route high-value Tasks and control Worker eligibility.
* [Activity Resource](/docs/taskrouter/api/activity.md): Learn about the Activity resource, which describes the current state of your Workers, including Activity properties, and how to create, read, update, and delete Activities.
* [Event Resource](/docs/taskrouter/api/event.md): TaskRouter logs Events for each state change in the Workspace, allowing you to build historical reporting and auditing for your routing use case.
* [TaskRouter Events reference](/docs/taskrouter/api/event/reference.md): Learn about TaskRouter Events and find descriptions of all Event Callbacks.
* [TaskRouter: REST API Reference](/docs/taskrouter/api.md): An overview of the TaskRouter API including the base URL for all TaskRouter resources and links to guides for best practices when building with this API.
* [Task Reservation Resource](/docs/taskrouter/api/reservations.md): Full API reference for the Task Reservations resource in the TaskRouter API. Find sample code that shows how to fetch (get) and update reservations.
* [Task Channel resource](/docs/taskrouter/api/task-channel.md): A full API reference for the Task Channel resource, including code samples to create, fetch, read, update, and delete Task Channels.
* [Task Queue resource](/docs/taskrouter/api/task-queue.md): Full API reference for the TaskQueue resource in the TaskRouter API. Find sample code showing how to create, fetch (get), read (list), update, and delete.
* [Task Resource](/docs/taskrouter/api/task.md): A TaskRouter Task represents a single item of work waiting to be processed. This overview covers task attributes, versions, and a Task lifecycle.
* [REST API: TaskQueue Statistics](/docs/taskrouter/api/taskqueue-statistics.md): Full API reference for the TaskQueue Statistics resource in the TaskRouter API. Sample code shows how to retrieve real-time, cumulative, and instance TaskQueue Statistics.
* [Worker Channel Resource](/docs/taskrouter/api/worker-channel.md): Full API reference for the Worker Channels resource in the TaskRouter API. Sample code shows how to fetch (get), read (list), and update worker channels.
* [Worker Reservation resource](/docs/taskrouter/api/worker-reservation.md): Full API reference for the TaskRouter API's Worker Reservation resource. Sample code shows how to fetch (get), read (list), and update a WorkerReservation.
* [Worker Resource](/docs/taskrouter/api/worker.md): Twilio TaskRouter allows you to create, update, delete, and retrieve Workers, which are entities that can perform tasks. A Worker might be an agent working in a call center, or a salesperson handling leads.
* [Worker Statistics Resource](/docs/taskrouter/api/worker/statistics.md): Full API reference for the TaskRouter Worker Statistics resource. Code samples show how to fetch a resource and retrieve worker statistics.
* [Workflow Statistics Resource](/docs/taskrouter/api/workflow-statistics.md): Learn about the Workflow Statistics resource, how to retrieve Workflow Statistics, RealTime Statistics, and Cumulative Statistics.
* [Workflow Resource](/docs/taskrouter/api/workflow.md): Full API reference for the Workflow resource in the Taskrouter REST API. Sample code shows how to create, fetch, read, update, and delete a Workflow.
* [REST API: Workspace Statistics](/docs/taskrouter/api/workspace-statistics.md): Learn about the Workspace Statistics TaskRouter provides. Find sample code for how to retrieve statistics, real-time statistics, and cumulative statistics for Workspaces.
* [Workspace Resource](/docs/taskrouter/api/workspace.md): A full reference for the Workspace Resource of the TaskRouter API, with code samples to create, read, update, fetch, update, and delete a Workspace.
* [Call Control Concepts | Appendix | Web Sequence Diagrams](/docs/taskrouter/contact-center-blueprint/call-control-concepts-web-sequence-diagrams.md): Web sequence diagrams for TaskRouter call control concepts, including blind (cold) transfer and warm transfer flows between caller, Twilio, and your app.
* [Call Control Concepts](/docs/taskrouter/contact-center-blueprint/call-control-concepts.md): A conceptual overview of best practices for TaskRouter call control for reporting and dashboard accuracy, including holds, transfers, monitor, and barge.
* [Using Chat and TaskRouter together | Appendix | Web Sequence Diagrams](/docs/taskrouter/contact-center-blueprint/chat-taskrouter-web-sequence-diagrams.md): Web sequence diagram for using Programmable Chat with TaskRouter, showing the flow from a customer starting a chat to an agent handling and completing the task.
* [Using Chat and TaskRouter Together](/docs/taskrouter/contact-center-blueprint/chat-taskrouter.md): Learn best practices for using Programmable Chat with TaskRouter for Contact Center use cases.
* [Dashboards](/docs/taskrouter/contact-center-blueprint/dashboards.md): Learn about common requirements for real-time dashboards for your TaskRouter contact center including data flow, summaries, queues, and agents.
* [Using Email and TaskRouter Together](/docs/taskrouter/contact-center-blueprint/email-taskrouter.md): Learn how to add Email as a channel to your contact center, by combining a REST based third party email service with TaskRouter.
* [Contact Center Blueprint](/docs/taskrouter/contact-center-blueprint.md): Learn how to build a contact center on Twilio. Reference code samples, architecture guidance, and design philosophies as you build out your contact center.
* [Reporting](/docs/taskrouter/contact-center-blueprint/reporting.md): Common reporting requirements for a contact center, including real-time dashboards and historical reports to ensure you have all the data you need.
* [Using SMS and TaskRouter Together | Web Sequence Diagrams](/docs/taskrouter/contact-center-blueprint/sms-taskrouter-web-sequence-diagrams.md): Web sequence diagram source for using SMS and TaskRouter together in a contact center. Copy the diagram code into websequencediagrams.com to customize the flow.
* [Using SMS and TaskRouter Together](/docs/taskrouter/contact-center-blueprint/sms-taskrouter.md): Learn the best practice for adding SMS as a channel to your contact center by combining Twilio Numbers, Programmable SMS, Programmable Chat, and TaskRouter.
* [Using TaskRouter Expressions](/docs/taskrouter/expression-syntax.md): TaskRouter uses a SQL-like expression syntax for binding Workers to TaskQueues and filtering Tasks into TaskQueues in a Workflow configuration. Learn how to compose expressions from  constants, JSON keys, as well as logical and comparison operators.
* [Assigning Tasks to Workers: Handling Assignment Callbacks](/docs/taskrouter/handle-assignment-callbacks.md): Learn how to handle Assignment Callbacks in TaskRouter, including parameters included in the HTTP POST request and ways to respond in your code.
* [How TaskRouter Works](/docs/taskrouter/how-taskrouter-works.md): Learn the basics of how TaskRouter, our system for distributing tasks in your contact center, works. Includes an example application flow and useful links.
* [TaskRouter: Skills-based routing for contact centers](/docs/taskrouter.md): TaskRouter is a skills-based routing system that provides the heart of a contact center that you can control from your code.
* [TaskRouter.js v1: Integrating TaskRouter to your browser-based applications](/docs/taskrouter/js-sdk-v1.md): Learn about integrating TaskRouter into your browser-based applications using the Javascript SDK.
* [TaskRouter.js v1: Constructing JWTs](/docs/taskrouter/js-sdk-v1/workspace/constructing-jwts.md): Generate JSON Web Tokens (JWTs) from your server to authorize which TaskRouter resources a client-side TaskRouter.js v1 application can access.
* [TaskRouter.js v1 Workspace: Managing resources in the browser](/docs/taskrouter/js-sdk-v1/workspace.md): The TaskRouter Javascript SDK allows developers to interact with the entire TaskRouter REST API by a simple JS API.
* [TaskRouter.js v1 TaskQueue: Managing a TaskQueue resource in the browser](/docs/taskrouter/js-sdk-v1/workspace/taskqueue.md): Learn how to manage a TaskQueue resource in the browser using the TaskRouter Javascript SDK.
* [TaskRouter.js v1 Worker: Managing workers in the browser](/docs/taskrouter/js-sdk-v1/workspace/worker.md): Comprehensive documentation about TaskRouter's JavaScript workers, used to route tasks in your web-based applications.
* [TaskRouter.js v2: Reconnect Logic](/docs/taskrouter/js-sdk-v2/reconnect.md): Documentation about how TaskRouter SDK v2 is reconnecting the WebSocket after disconnection.
* [TaskRouter.js v2 and v3: Integrating TaskRouter with your browser-based applications](/docs/taskrouter/js-sdk.md): Learn about integrating TaskRouter into your browser-based applications using TaskRouter JavaScript SDK v2 and v3.
* [Lifecycle of a Task: Task state](/docs/taskrouter/lifecycle-task-state.md): Learn the basics of the various states of a Task, the core of TaskRouter, including the states a Task can go through as it moves from pending to completed.
* [Lifecycle of a Task: Workflows and Assignment](/docs/taskrouter/lifecycle-task-workflows-and-assignment.md): Learn about the lifecycle of a TaskRouter Task, how it moves through a Workflow, and how it gets assigned to a Worker.
* [TaskRouter resource limits](/docs/taskrouter/limits.md): Twilio TaskRouter has default limits on certain resources, configuration parameters, and endpoints. If you are running into these limits, please reach out to our support team. We're happy to help work with you to increase some of these limits or help optimize how you use TaskRouter.
* [Upgrade to TaskRouter SDK version 2](/docs/taskrouter/migrate-js-sdk-to-v2.md): Migrate from TaskRouter JavaScript SDK version 1 to version 2: callbacks to promises, worker activity changes, event listening, and breaking changes.
* [Multitasking](/docs/taskrouter/multitasking.md): TaskRouter Multitasking allows a worker to handle multiple tasks of different types in parallel.
* [Ordering Workers](/docs/taskrouter/order-workers.md): Learn how to use the order\_by expression to designate in what order Workers are assigned tasks when using TaskRouter.
* [Queue Ordering](/docs/taskrouter/queue-ordering-last-first-out-lifo.md): Learn about how TaskQueue handles ordering with First In, First Out (FIFO) or Last In, First Out (LIFO).
* [TaskRouter .Net Quickstart](/docs/taskrouter/quickstart/csharp.md): In this Quickstart, build a simplified version of a multi-channel sales and technical support system using Twilio TaskRouter and .Net.
* [Creating Tasks and Accepting Reservations: Accept a Reservation using Assignment Callback Instructions](/docs/taskrouter/quickstart/csharp/reservations-accept-callback.md): Accept a TaskRouter Reservation automatically with an assignment callback instruction, by returning an accept instruction in a synchronous HTTP response from your C# server.
* [Creating Tasks and Accepting Reservations: Accept a Reservation using the REST API](/docs/taskrouter/quickstart/csharp/reservations-accept-rest.md): Accept or reject a TaskRouter Task Reservation by making an HTTP POST request to a Reservation instance resource with the TaskSid and ReservationSid in C#.
* [Creating Tasks and Accepting Reservations: Set up the Assignment Callback URL](/docs/taskrouter/quickstart/csharp/reservations-assignment-callback.md): Set up a TaskRouter Assignment Callback URL with a C# web server so TaskRouter can notify your application when a Worker is reserved to perform a Task.
* [Creating Tasks and Accepting Reservations: Create a Task using the REST API](/docs/taskrouter/quickstart/csharp/reservations-create-task-rest.md): Create a TaskRouter Task with the REST API in C#, then bring an eligible Worker online to trigger an automatic Task Reservation and assignment callback.
* [Setting up a TaskRouter Workspace: Add and Configure TaskQueues](/docs/taskrouter/quickstart/csharp/setup-add-task-queues.md): Add and configure TaskRouter TaskQueues that route Tasks to Workers by language skill, using SQL-like Target Workers expressions in the TaskRouter console.
* [Setting up a TaskRouter Workspace: Add and Configure Workers](/docs/taskrouter/quickstart/csharp/setup-add-workers.md): Add and configure TaskRouter Workers in the console, defining their skills with JSON attributes so TaskRouter can route Tasks based on language and other criteria.
* [Setting up a TaskRouter Workspace: Add and Configure a Workflow](/docs/taskrouter/quickstart/csharp/setup-add-workflow.md): Add and configure a TaskRouter Workflow with routing configurations that direct incoming Tasks to the correct TaskQueue based on the caller's selected language.
* [Setting up a TaskRouter Workspace: Create a Workspace](/docs/taskrouter/quickstart/csharp/setup-create-workspace.md): Create a TaskRouter Workspace, the container element for any TaskRouter application, using the TaskRouter console or the REST API.
* [Create Tasks from Phone Calls using TwiML: Create a TaskRouter Task using \<Enqueue>](/docs/taskrouter/quickstart/csharp/twiml-create-task.md): Create a TaskRouter Task from an incoming phone call in C# using the TwiML \<Enqueue> verb, routing the call to a Task Queue by selected language.
* [Create Tasks from Phone Calls using TwiML: Dequeue a Call to a Worker](/docs/taskrouter/quickstart/csharp/twiml-dequeue-call.md): Dequeue a TaskRouter call to an eligible Worker in C#. Return a dequeue Assignment Instruction to bridge the caller to the Worker's contact\_uri.
* [Create Tasks from Phone Calls using TwiML: End-to-End Phone Call Task Assignment](/docs/taskrouter/quickstart/csharp/twiml-end-to-end.md): Test the end-to-end TaskRouter phone call flow in C#: create a Task from an incoming call, route it to an available Worker, and bridge the call.
* [Create Tasks from Phone Calls using TwiML: Receive an Incoming Call](/docs/taskrouter/quickstart/csharp/twiml-receive-call.md): Receive an incoming Twilio phone call in C# and prompt the caller for a language with TwiML \<Gather> before creating a TaskRouter Task.
* [Control Worker Activities using Worker.js: Add an Agent UI to our Project](/docs/taskrouter/quickstart/java/agent-ui-add-project.md): Add a real-time agent user interface to a TaskRouter Java app using TaskRouter.js, letting Workers view and control their own Activity state.
* [TaskRouter Java Quickstart](/docs/taskrouter/quickstart/java.md): In this Quickstart, build a simplified version of a multichannel sales and technical support system using Twilio TaskRouter and Java.
* [Creating Tasks and Accepting Reservations: Accept a Reservation using Assignment Callback Instructions](/docs/taskrouter/quickstart/java/reservations-accept-callback.md): Accept a TaskRouter Reservation automatically by returning an 'accept' assignment instruction from your Assignment Callback URL, using Java and the REST API.
* [Creating Tasks and Accepting Reservations: Accept a Reservation using the REST API](/docs/taskrouter/quickstart/java/reservations-accept-rest.md): Accept a TaskRouter Reservation with the REST API by making a POST request to the Reservation instance resource with ReservationStatus set to accepted.
* [Creating Tasks and Accepting Reservations: Set up the Assignment Callback URL](/docs/taskrouter/quickstart/java/reservations-assignment-callback.md): Set up a TaskRouter Assignment Callback URL with a Java servlet so TaskRouter can notify your server when a Worker is reserved to perform a Task.
* [Creating Tasks and Accepting Reservations: Create a Task using the REST API](/docs/taskrouter/quickstart/java/reservations-create-task-rest.md): Create a TaskRouter Task with the REST API using Java or curl, then bring an eligible Worker online to trigger an automatic Task Reservation.
* [Setting up a TaskRouter Workspace: Add and Configure TaskQueues](/docs/taskrouter/quickstart/java/setup-add-task-queues.md): Add and configure TaskRouter TaskQueues that route Tasks to Workers by language skill, using Target Workers Expressions with the HAS operator.
* [Setting up a TaskRouter Workspace: Add and Configure Workers](/docs/taskrouter/quickstart/java/setup-add-workers.md): Add and configure TaskRouter Workers in the console, defining JSON Worker Attributes such as language skills to route incoming Tasks by capability.
* [Setting up a TaskRouter Workspace: Add and Configure a Workflow](/docs/taskrouter/quickstart/java/setup-add-workflow.md): Add and configure a TaskRouter Workflow with routing configurations that match incoming Tasks to the right Task Queue based on the caller selected language.
* [Setting up a TaskRouter Workspace: Create a Workspace](/docs/taskrouter/quickstart/java/setup-create-workspace.md): Create a TaskRouter Workspace, the container element for any TaskRouter application, using the REST API or the TaskRouter console in the Twilio Console.
* [Create Tasks from Phone Calls using TwiML: Create a TaskRouter Task using \<Enqueue>](/docs/taskrouter/quickstart/java/twiml-create-task.md): Create a TaskRouter Task from an incoming Twilio phone call using the TwiML \<Enqueue> verb in Java, routing the caller to a Task Queue based on their selected language.
* [Create Tasks from Phone Calls using TwiML: Dequeue a Call to a Worker](/docs/taskrouter/quickstart/java/twiml-dequeue-call.md): Use a TaskRouter dequeue Assignment Instruction in Java to connect an enqueued caller to an eligible Worker at their contact\_uri when the Worker becomes available.
* [Create Tasks from Phone Calls using TwiML: End-to-End Phone Call Task Assignment](/docs/taskrouter/quickstart/java/twiml-end-to-end.md): Test the end-to-end TaskRouter phone call flow in Java: create a Task from an incoming call, assign it to an available Worker, and bridge the dequeued call.
* [Create Tasks from Phone Calls using TwiML: Receive an Incoming Call](/docs/taskrouter/quickstart/java/twiml-receive-call.md): Handle an incoming Twilio phone call in Java with TaskRouter TwiML, using \<Gather> and \<Say> to prompt the caller to select a preferred language before creating a Task.
* [Control Worker Activities using Worker.js: Add an Agent UI to our Project](/docs/taskrouter/quickstart/php/agent-ui-add-project.md): Build a real-time agent UI for Twilio TaskRouter using TaskRouter.js and PHP, letting Workers change Activity state and receive Reservation event notifications.
* [TaskRouter: PHP quickstart](/docs/taskrouter/quickstart/php.md): In this Quickstart, build a simplified version of a multichannel sales and technical support system using Twilio TaskRouter and PHP.
* [Creating Tasks and Accepting Reservations: Accept a Reservation using Assignment Callback Instructions](/docs/taskrouter/quickstart/php/reservations-accept-callback.md): Accept a Twilio TaskRouter Reservation automatically by returning an 'accept' assignment instruction from your Assignment Callback URL in a synchronous HTTP response.
* [Creating Tasks and Accepting Reservations: Accept a Reservation using the REST API](/docs/taskrouter/quickstart/php/reservations-accept-rest.md): Accept or reject a Twilio TaskRouter Reservation by sending an HTTP POST request to the Reservation instance resource with the TaskSid and ReservationSid.
* [Creating Tasks and Accepting Reservations: Set up the Assignment Callback URL](/docs/taskrouter/quickstart/php/reservations-assignment-callback.md): Set up an Assignment Callback URL for Twilio TaskRouter so the system can notify your PHP server when a Worker is reserved to perform a Task.
* [Creating Tasks and Accepting Reservations: Create a Task using the REST API](/docs/taskrouter/quickstart/php/reservations-create-task-rest.md): Learn how to create a Task using the REST API.
* [Setting up a TaskRouter Workspace: Add and Configure TaskQueues](/docs/taskrouter/quickstart/php/setup-add-task-queues.md): Add and configure Twilio TaskRouter TaskQueues that assign Tasks to Workers based on Worker attributes, using SQL-like Target Workers Expressions for language routing.
* [Setting up a TaskRouter Workspace: Add and Configure Workers](/docs/taskrouter/quickstart/php/setup-add-workers.md): Learn how to add and configure Workers in this part of the Setting up a TaskRouter Workspace guide.
* [Setting up a TaskRouter Workspace: Add and Configure a Workflow](/docs/taskrouter/quickstart/php/setup-add-workflow.md): Add and configure a TaskRouter Workflow with Routing Configurations that route incoming Tasks to the right Task Queue based on the caller-selected language.
* [Setting up a TaskRouter Workspace: Create a Workspace](/docs/taskrouter/quickstart/php/setup-create-workspace.md): Create a TaskRouter Workspace, the container element for any TaskRouter application, using the TaskRouter console or the REST API.
* [Create Tasks from Phone Calls using TwiML: Create a TaskRouter Task using \<Enqueue>](/docs/taskrouter/quickstart/php/twiml-create-task.md): Create a TaskRouter Task from an incoming phone call using the TwiML \<Enqueue> verb, routing the caller to a Task Queue based on their selected language.
* [Create Tasks from Phone Calls using TwiML: Dequeue a Call to a Worker](/docs/taskrouter/quickstart/php/twiml-dequeue-call.md): Use a TaskRouter dequeue assignment instruction to bridge a queued caller to an eligible Worker at their contact\_uri when the Worker becomes available.
* [Create Tasks from Phone Calls using TwiML: End-to-End Phone Call Task Assignment](/docs/taskrouter/quickstart/php/twiml-end-to-end.md): Test the end-to-end TaskRouter flow: create a Task from an incoming phone call, make a Worker available, and bridge the call to the eligible Worker.
* [Create Tasks from Phone Calls using TwiML: Receive an Incoming Call](/docs/taskrouter/quickstart/php/twiml-receive-call.md): Receive an incoming Twilio phone call with TwiML and prompt the caller to select a language using the \<Gather> verb before creating a TaskRouter Task.
* [Control Worker Activities using Worker.js: Add an Agent UI to our Project](/docs/taskrouter/quickstart/python/agent-ui-add-project.md): Build an agent UI for your TaskRouter Python project with Flask and TaskRouter.js, generating a Worker capability token and rendering an agent.html template.
* [TaskRouter Python Quickstart](/docs/taskrouter/quickstart/python.md): In this Quickstart, build a simplified version of a multi-channel sales and technical support system using Twilio TaskRouter and Python.
* [Creating Tasks and Accepting Reservations: Accept a Reservation using Assignment Callback Instructions](/docs/taskrouter/quickstart/python/reservations-accept-callback.md): Accept a TaskRouter Reservation automatically by returning an 'accept' assignment instruction from your Python Flask Assignment Callback URL over a synchronous HTTP response.
* [Creating Tasks and Accepting Reservations: Accept a Reservation using the REST API](/docs/taskrouter/quickstart/python/reservations-accept-rest.md): Accept or reject a TaskRouter Task Reservation by sending an HTTP POST to the Reservation instance resource with ReservationStatus, using Python or curl.
* [Creating Tasks and Accepting Reservations: Set up the Assignment Callback URL](/docs/taskrouter/quickstart/python/reservations-assignment-callback.md): Set up a TaskRouter Assignment Callback URL with a Python Flask server and expose it to Twilio using ngrok so TaskRouter can notify you when a Worker is reserved.
* [Creating Tasks and Accepting Reservations: Create a Task using the REST API](/docs/taskrouter/quickstart/python/reservations-create-task-rest.md): Create a TaskRouter Task with the REST API using Python and curl, then bring an eligible Worker online to trigger a Reservation at your Assignment Callback URL.
* [Setting up a TaskRouter Workspace: Add and Configure TaskQueues](/docs/taskrouter/quickstart/python/setup-add-task-queues.md): Create and configure TaskRouter TaskQueues that route Tasks to Workers by attribute, using target Worker expressions to match language skills.
* [Setting up a TaskRouter Workspace: Add and configure Workers](/docs/taskrouter/quickstart/python/setup-add-workers.md): Add and configure TaskRouter Workers, the people or processes that perform Tasks, and set JSON attributes such as language skills for routing.
* [Setting up a TaskRouter Workspace: Add and Configure a Workflow](/docs/taskrouter/quickstart/python/setup-add-workflow.md): Add and configure a TaskRouter Workflow with Routing Configurations that match Task attributes to the correct TaskQueue for language-based routing.
* [Setting up a TaskRouter Workspace: Create a Workspace](/docs/taskrouter/quickstart/python/setup-create-workspace.md): Create a TaskRouter Workspace, the container element for a TaskRouter application, using the TaskRouter console or the REST API.
* [Create Tasks from Phone Calls using TwiML: Create a TaskRouter Task using \<Enqueue>](/docs/taskrouter/quickstart/python/twiml-create-task.md): Create a TaskRouter Task from an incoming phone call in Python using the TwiML \<Enqueue> verb to route callers to the correct TaskQueue.
* [Create Tasks from Phone Calls using TwiML: Dequeue a Call to a Worker](/docs/taskrouter/quickstart/python/twiml-dequeue-call.md): Use a TaskRouter dequeue Assignment Instruction in Python to call an eligible Worker at their contact\_uri and bridge them to the waiting caller.
* [Create Tasks from Phone Calls using TwiML: End-to-End Phone Call Task Assignment](/docs/taskrouter/quickstart/python/twiml-end-to-end.md): Test the TaskRouter Python TwiML call flow end-to-end: create a Task from an incoming call, assign it to a Worker, and bridge the two parties.
* [Create Tasks from Phone Calls using TwiML: Receive an Incoming Call](/docs/taskrouter/quickstart/python/twiml-receive-call.md): Configure a Twilio phone number and Python Flask endpoint to receive an incoming call and create a TaskRouter Task using TwiML in the Python Quickstart.
* [Control Worker Activities using Worker.js: Add an Agent UI to our Project](/docs/taskrouter/quickstart/ruby/agent-ui-add-project.md): Build a realtime agent UI with TaskRouter.js and a Ruby Sinatra endpoint that lets a Worker control their Activity state and see incoming call events.
* [TaskRouter Ruby Quickstart](/docs/taskrouter/quickstart/ruby.md): Build a multi-channel sales and support routing app with Twilio TaskRouter and Ruby. This Quickstart covers Workspaces, Tasks, Reservations, TwiML, and TaskRouter.js.
* [Creating Tasks and Accepting Reservations: Accept a Reservation using Assignment Callback Instructions](/docs/taskrouter/quickstart/ruby/reservations-accept-callback.md): Accept a TaskRouter Reservation automatically by returning an accept assignment instruction in a synchronous HTTP response from your Assignment Callback URL in Ruby.
* [Creating Tasks and Accepting Reservations: Accept a Reservation using the REST API](/docs/taskrouter/quickstart/ruby/reservations-accept-rest.md): Accept a TaskRouter Reservation with the REST API by sending an HTTP POST to a Reservation instance resource with ReservationStatus set to accepted, using Ruby or curl.
* [Creating Tasks and Accepting Reservations: Set up the Assignment Callback URL](/docs/taskrouter/quickstart/ruby/reservations-assignment-callback.md): Set up an Assignment Callback URL with a Ruby Sinatra server so TaskRouter can notify you when a Worker is reserved for a Task, exposed to Twilio with ngrok.
* [Creating Tasks and Accepting Reservations: Create a Task using the REST API](/docs/taskrouter/quickstart/ruby/reservations-create-task-rest.md): Create a TaskRouter Task with the REST API in Ruby, bring an eligible Worker online, and observe the Task Reservation lifecycle in this Quickstart step.
* [Setting up a TaskRouter Workspace: Add and Configure TaskQueues](/docs/taskrouter/quickstart/ruby/setup-add-task-queues.md): Add and configure TaskRouter TaskQueues that route Tasks to Workers by language skill using Target Workers Expressions in this TaskRouter Quickstart step.
* [Setting up a TaskRouter Workspace: Add and Configure Workers](/docs/taskrouter/quickstart/ruby/setup-add-workers.md): Create and configure TaskRouter Workers with JSON language attributes so TaskRouter can route calls to agents by skill in this TaskRouter Quickstart step.
* [Setting up a TaskRouter Workspace: Add and Configure a Workflow](/docs/taskrouter/quickstart/ruby/setup-add-workflow.md): Add a TaskRouter Workflow with Routing Configurations that direct Tasks to the right TaskQueue based on the caller selected language in this Quickstart step.
* [Setting up a TaskRouter Workspace: Create a Workspace](/docs/taskrouter/quickstart/ruby/setup-create-workspace.md): Create a TaskRouter Workspace, the container element for any TaskRouter application, using the TaskRouter console in this TaskRouter Quickstart step.
* [Setting up a TaskRouter Workspace: Understanding Activities](/docs/taskrouter/quickstart/ruby/setup-understanding-activities.md): Understand TaskRouter Activities, the discrete states a Worker can be in, and how the Available property determines eligibility for new Task Reservations.
* [Part 1. Setting up a TaskRouter Workspace](/docs/taskrouter/quickstart/ruby/setup.md): Set up a TaskRouter Workspace in Ruby by creating Workers, TaskQueues, a Workflow, and Activities in Part 1 of the TaskRouter Ruby Quickstart.
* [Create Tasks from Phone Calls using TwiML: Create a TaskRouter Task using \<Enqueue>](/docs/taskrouter/quickstart/ruby/twiml-create-task.md): Create a TaskRouter Task from an incoming phone call using the TwiML \<Enqueue> verb in Ruby, routing callers to a TaskQueue by their selected language.
* [Create Tasks from Phone Calls using TwiML: Dequeue a Call to a Worker](/docs/taskrouter/quickstart/ruby/twiml-dequeue-call.md): Use a TaskRouter dequeue Assignment Instruction in Ruby to bridge a queued caller to an eligible Worker at their contact\_uri when the Worker becomes available.
* [Create Tasks from Phone Calls using TwiML: End-to-End Test](/docs/taskrouter/quickstart/ruby/twiml-end-to-end.md): Test a TaskRouter app end to end: create a Task from an incoming phone call, make a Worker available, and dequeue the call to connect the caller to an agent.
* [Create Tasks from Phone Calls using TwiML: Receive an Incoming Call](/docs/taskrouter/quickstart/ruby/twiml-receive-call.md): Set up a Ruby and Sinatra endpoint to receive an incoming Twilio phone call and use TwiML to prompt the caller for a language before creating a TaskRouter Task.
* [Lifecycle of a Task: Timeout evaluation](/docs/taskrouter/task-evaluation.md): Learn how Timeouts work with Queues and Tasks in TaskRouter.
* [Time of Day Routing for TaskRouter](/docs/taskrouter/time-of-day-routing.md): Learn about the supported time of day expressions in TaskRouter.
* [Dynamic Call Center with C# and ASP.NET MVC](/docs/taskrouter/tutorials/dynamic-call-center-csharp-mvc.md): Build a dynamic, multi-agent customer service call center with Twilio, TaskRouter, C#, and ASP.NET.
* [Dynamic Call Center with Java and Servlets](/docs/taskrouter/tutorials/dynamic-call-center-java-servlets.md): Build a dynamic, multi-agent customer service call center with Twilio, TaskRouter, Java, and Servlets.
* [Dynamic Call Center with Node.js and Express](/docs/taskrouter/tutorials/dynamic-call-center-node-express.md): Build a dynamic, multi-agent customer service call center with Twilio, TaskRouter, Node.js, and Express.
* [Dynamic Call Center with PHP and Laravel](/docs/taskrouter/tutorials/dynamic-call-center-php-laravel.md): Build a dynamic, multi-agent customer service call center with Twilio, TaskRouter, PHP, and Laravel.
* [Dynamic call center with Python and Django](/docs/taskrouter/tutorials/dynamic-call-center-python-django.md): Build a dynamic, multi-agent customer service call center with Twilio, TaskRouter, Python, and Django.
* [Dynamic Call Center with Ruby and Rails](/docs/taskrouter/tutorials/dynamic-call-center-ruby-rails.md): Build a dynamic, multi-agent customer service call center with Twilio, TaskRouter, and Ruby on Rails.
* [Queueing Twilio calls with TaskRouter](/docs/taskrouter/twiml-queue-calls.md): Learn how to queue calls with TaskRouter with code samples that shows how to route calls and bridge a call to a worker.
* [Skipping based on Worker availability](/docs/taskrouter/worker-presence.md): Learn why you might want to skip to the next routing step if there are no available workers and what your options are.
* [Workflows Overview](/docs/taskrouter/workflow-configuration.md): This page provides an overview of the basic concepts of Workflows, rules that define how tasks are distributed TaskRouter.
* [Known Agent Routing](/docs/taskrouter/workflow-configuration/known-agent-routing.md): Are your customers trying to talk to the same agent that helped them previously? Optimize and personalize your customer service by leveraging preferred (known) agent routing for tasks.

## Trust Hub

* [API: Create a Starter Profile](/docs/trust-hub/trusthub-rest-api/api-create-a-starter-profile.md): Create a Starter Profile with the Trust Hub API by building the bundle, adding business and address data, assigning a Primary Customer Profile, and submitting it.
* [API: Create a Secondary Customer Profile](/docs/trust-hub/trusthub-rest-api/api-create-secondary-customer-profile.md): Create a Secondary Customer Profile using the Trust Hub API.
* [Console: Create a Primary Customer Profile](/docs/trust-hub/trusthub-rest-api/console-create-a-primary-customer-profile.md): Learn to create a primary customer profile in the Twilio Console, from inputting general information to submit for approval.
* [Customer Profiles](/docs/trust-hub/trusthub-rest-api/customer-profiles.md): Create, find, update, and delete a Twilio Customer Profile in Trust Hub. Submit your business or individual identity data for verification and approval.
* [CustomerProfileChannelEndpointAssignment Resource](/docs/trust-hub/trusthub-rest-api/customer-profiles/channel-endpoint-assignments.md): Create, fetch, list, and delete CustomerProfileChannelEndpointAssignments with the Trust Hub API to assign phone numbers to a Customer Profile.
* [CustomerProfileEntityAssignment Resource](/docs/trust-hub/trusthub-rest-api/customer-profiles/entity-assignments.md): API reference for the TrustHub CustomerProfileEntityAssignment Resource. Create, fetch, list, and delete EndUser, SupportingDocument, and CustomerProfile assignments.
* [CustomerProfileEvaluation Resource](/docs/trust-hub/trusthub-rest-api/customer-profiles/evaluations.md): API reference for the TrustHub CustomerProfileEvaluation Resource. Create, fetch, and list evaluations to check a CustomerProfile against its Policies Resource.
* [CustomerProfile Resource](/docs/trust-hub/trusthub-rest-api/customer-profiles.md): A full API reference for the CustomerProfile Resource on the TrustHub REST API, with code samples to create, fetch, read, update, and delete.
* [EndUser Resource](/docs/trust-hub/trusthub-rest-api/enduser-resource.md): API reference for the EndUser Resource in the TrustHub API.
* [EndUserType resource](/docs/trust-hub/trusthub-rest-api/endusertype-resource.md): API reference for the TrustHub EndUserType Resource. Fetch and list EndUserTypes to see the structure and required fields of each TrustHub EndUser.
* [TrustHub REST API](/docs/trust-hub/trusthub-rest-api.md): Learn about all of the resources available in the TrustHub REST API.
* [SupportingDocument Resource](/docs/trust-hub/trusthub-rest-api/supportingdocument-resource.md): API reference for the TrustHub SupportingDocument Resource. Create, fetch, list, update, and delete supporting documents required for TrustHub compliance.
* [SupportingDocumentType Resource](/docs/trust-hub/trusthub-rest-api/supportingdocumentdype-resource.md): API reference for the TrustHub SupportingDocumentType Resource. Fetch and list SupportingDocumentTypes to see the fields required for each document type.
* [TrustProductChannelEndpointAssignment Resource](/docs/trust-hub/trusthub-rest-api/trust-products/channel-endpoint-assignments-tp.md): API reference for the TrustHub TrustProductChannelEndpointAssignment Resource. Create, fetch, list, and delete phone number assignments to a TrustProduct.
* [TrustProductEntityAssignment Resource](/docs/trust-hub/trusthub-rest-api/trust-products/entity-assignments-tp.md): API reference for the TrustHub TrustProductEntityAssignment Resource. Create, fetch, list, and delete EndUser and CustomerProfile assignments to a TrustProduct.
* [TrustProductEvaluation Resource](/docs/trust-hub/trusthub-rest-api/trust-products/evaluations-tp.md): API reference for the TrustProductEvaluation resource in the Twilio TrustHub API. Learn how to create, fetch, and list evaluations for a TrustProduct.
* [TrustProduct Resource](/docs/trust-hub/trusthub-rest-api/trust-products.md): Full API reference for the TrustProduct resource in the TrustHub API. Learn how to create, fetch, read, update, and delete.

## Twilio Bulk Messaging API

* [Sender Pools](/docs/bulk-messaging/sender-pools.md): Learn how to manage sender resources with Sender Pools in Twilio Bulk Messaging.

* [Tags](/docs/bulk-messaging/tags.md): Learn what Tags are, how to add custom key-value metadata to resources, personalize tag values per recipient with Liquid, and filter resources by tag.

## Twilio CLI

* [Get a phone number and send your first SMS](/docs/twilio-cli/examples/explore-sms.md): Learn how to get a Twilio phone number and send your first text message using only the command line.
* [Find more examples](/docs/twilio-cli/examples/find-more-examples.md): Find Twilio CLI command examples and sample inputs on any Twilio API Reference page by selecting twilio-cli from the list of code sample languages.
* [CLI examples](/docs/twilio-cli/examples.md): A collection of examples that show you how to do various things with Twilio's CLI.
* [Send email with Twilio SendGrid](/docs/twilio-cli/examples/send-email-sendgrid.md): Send emails from your terminal with the Twilio CLI SendGrid integration. Set your API key, configure defaults, and send emails with text and attachments.
* [Autocomplete](/docs/twilio-cli/general-usage/autocomplete.md): Learn how to enable command autocompletion for the Twilio CLI
* [Configuration](/docs/twilio-cli/general-usage/configuration.md): Learn how to configure settings for the Twilio CLI
* [CLI general usage](/docs/twilio-cli/general-usage.md): Understand the basics of using the CLI. Learn how to use multiple accounts, environment variables, API core commands, webhooks, and more.
* [CLI Limitations](/docs/twilio-cli/general-usage/limitations.md): Understand the limitations of the Twilio CLI
* [Logging and debugging](/docs/twilio-cli/general-usage/logging-and-debugging.md): Learn how to modify the logging level of the Twilio CLI and how it can speed up debugging
* [Output formatting and filtering](/docs/twilio-cli/general-usage/output-formatting-and-filtering.md): Learn how to request different format outputs and filtered data from the Twilio CLI
* [Profiles](/docs/twilio-cli/general-usage/profiles.md): Learn how to manage your Twilio credentials and settings in the Twilio CLI with Profiles
* [Regional](/docs/twilio-cli/general-usage/regional.md): Learn how to make use of Twilio's regional capabilities while issuing CLI commands
* [Subaccounts](/docs/twilio-cli/general-usage/subaccounts.md): Learn how to use Twilio subaccounts with the Twilio CLI
* [Work with webhooks](/docs/twilio-cli/general-usage/work-with-webhooks.md): Learn how to quickly connect Twilio phone numbers to webhooks or your local development environment with the Twilio CLI
* [Use the Twilio CLI Docker image](/docs/twilio-cli/getting-started/docker.md): Learn how to use and configure twilio-cli using the official Docker image.
* [Install the Twilio CLI](/docs/twilio-cli/getting-started/install.md): Learn how to install the latest version of twilio-cli on any operating system.
* [Install past versions of the Twilio CLI](/docs/twilio-cli/getting-started/past-versions.md): Learn how to install specific past versions of the twilio-cli for rare use cases
* [Update](/docs/twilio-cli/getting-started/update.md): Learn how to update Twilio CLI to the latest version on your machine
* [Twilio CLI](/docs/twilio-cli.md): Learn about the Twilio Command Line Interface
* [CLI Plugins](/docs/twilio-cli/plugins.md): Learn how to extend the Twilio CLI by authoring (and optionally publishing) your own plugins.
* [Command-Line Interface (CLI) Quickstart](/docs/twilio-cli/quickstart.md): Learn how to quickly get started with the Twilio CLI to unleash the power of Twilio from your command line.
* [Uninstall the Twilio CLI](/docs/twilio-cli/uninstall.md): Learn how to remove twilio-cli from your system

## Twilio Content Template Builder

* [twilio/carousel](/docs/content/carousel.md): Drive interaction with Twilio/carousel, a versatile tool to display your services or products in a visually engaging carousel format. Incorporate media, text, and buttons in each card to enhance user experience on WhatsApp and RCS.
* [Postman Collection](/docs/content/content-api-postman-collection.md): Download the Twilio Content Template Builder Postman collection to explore and test Content API requests for creating and sending content templates.
* [Content API Public Endpoints](/docs/content/content-api-resources.md): Learn how to create, retrieve, submit for approval, and delete templates by using the Twilio Content API.
* [Content Types Overview](/docs/content/content-types-overview.md): Compare Twilio Content API content types, including channel support, media types, and WhatsApp approval requirements for SMS, RCS, WhatsApp, and Messenger.
* [Content API Quickstart](/docs/content/create-and-send-your-first-content-api-template.md): Create and send your first Twilio Content API template. Follow steps to build a quick-reply template, submit it for WhatsApp approval, and send a message.
* [Create templates with the Content Template Builder in Console](/docs/content/create-templates-with-the-content-template-builder.md): Learn how to create and manage templates across channels such as WhatsApp, RCS, Facebook Messenger, MMS, and SMS by using the Content Template Builder in Twilio Console.
* [Eligibility Badge Legend](/docs/content/eligibility-badge-legend.md): Understand the eligibility badge icons in the Content Template Builder that show whether a template is approved, rejected, or pending WhatsApp approval.
* [FAQs and Troubleshooting](/docs/content/faqs-and-troubleshooting.md): Answers to common questions and troubleshooting tips for Twilio Content Templates, including formatting, emojis, URLs, languages, and Content API limits.
* [twilio/flows](/docs/content/flows.md): Collect multiple pieces of customer input by using Twilio Flows.
* [Twilio Content Template Builder](/docs/content.md): Create and send omnichannel rich content templates across any Twilio-supported channel. The Content Template Builder provides both a no-code Console UI and an API for programmatic creation and management.
* [Manage your templates with the Content Template Builder](/docs/content/manage-your-templates-with-the-content-template-builder.md): Learn how to manage your templates using the Content Template Builder in the Twilio Console, including searching, filtering, viewing details, and submitting templates for WhatsApp approval.
* [Content Templates Overview](/docs/content/overview.md): Learn about the Content Template Builder and Content API to create and manage templated messages and rich content across multiple communication channels.
* [Send templates created with the Content Template Builder](/docs/content/send-templates-created-with-the-content-template-builder.md): Learn how to send messages using templates created with the Content Template Builder in Twilio's Messaging Service.
* [Session Definitions](/docs/content/session-definitions.md): Understand user-initiated and business-initiated WhatsApp sessions, approval needs, and how to use Twilio APIs for seamless messaging.
* [twilio/call-to-action](/docs/content/twilio-call-to-action.md): Use the twilio/call-to-action content type to add tappable buttons that launch a website, call a phone number, copy a coupon code, or start a WhatsApp voice call.
* [twilio/catalog](/docs/content/twilio-catalog.md): Use the twilio/catalog content type to send single-product, multi-product, and full-catalog WhatsApp messages so customers can browse, ask about, and order products.
* [twilio/location](/docs/content/twilio-location.md): Learn how to use the \`twilio/location\` type to send location pins and optional labels in your messages.
* [twilio/media](/docs/content/twilio-media.md): Use the twilio/media content type to send file attachments or long text over MMS, RCS, WhatsApp, and Facebook Messenger, with up to 16 MB of media on WhatsApp.
* [twilio/pay](/docs/content/twilio-pay.md): Complete financial transactions in-app with the twilio/pay content type, which sends Pix payment order details and status messages over WhatsApp.
* [twilio/quick-reply](/docs/content/twilio-quick-reply.md): Send interactive messages with up to ten quick-reply buttons over WhatsApp or Facebook Messenger by using the twilio/quick-reply content type.
* [twilio/text](/docs/content/twilio-text.md): Learn about the \`twilio/text\` content type for plain text-based content and how to use it with content templates, variables, and supported channels.
* [twilio/card](/docs/content/twiliocard.md): Learn how to define and send a twilio/card content template, including required fields, supported channels, limitations, and data parameters.
* [twilio/list-picker](/docs/content/twiliolist-picker.md): Send a menu of up to 10 selectable options over WhatsApp with the twilio/list-picker content type. Learn its data parameters, channels, and limits.
* [Using Content Templates with Studio](/docs/content/using-content-templates-with-studio.md): Send rich messaging content from Studio Flows using Content Template SIDs and react to rich inbound message metadata in the Send Message and Split widgets.
* [Using Facebook Messenger with Content Templates](/docs/content/using-facebook-messenger-with-content-editor.md): Set up a Facebook Messenger (FBM) sender, add it to a Messaging Service, configure webhooks, and send Content Templates over Facebook Messenger with Twilio.
* [Using Variables with Content Templates](/docs/content/using-variables-with-content-api.md): Add dynamic variables to Content Templates with the Content API or Content Template Builder, and follow WhatsApp variable rules for approved templates.
* [whatsapp/authentication](/docs/content/whatsappauthentication.md): Deliver verified one-time passwords on WhatsApp with ease using pre-approved templates. Ensure security and compliance with WhatsApp guidelines.
* [whatsapp/card](/docs/content/whatsappcard.md): Learn how to create and approve WhatsApp card templates with media and variables. Ensure compliance with WhatsApp's guidelines for seamless messaging.

## Twilio Conversations

* [Create an AI-ready knowledge base](/docs/conversations/knowledge/create-an-ai-ready-knowledge-base.md): Create and structure a knowledge base in Enterprise Knowledge to provide context for AI tools.
* [Enterprise Knowledge](/docs/conversations/knowledge.md): Enterprise Knowledge allows you to pull data from a website or raw text and process it for information retrieval and AI workflows.
* [Using Enterprise Knowledge APIs](/docs/conversations/knowledge/knowledge-apis.md): Authenticate and use the Enterprise Knowledge APIs to manage knowledge bases and sources.
* [Enterprise Knowledge limits](/docs/conversations/knowledge/knowledge-limits.md): Product and API resource limits for Enterprise Knowledge.&#x20;
* [Enterprise Knowledge observability](/docs/conversations/knowledge/observability.md): Monitor and debug Enterprise Knowledge with structured event logging, error diagnostics, alerting, and traceability.
* [Using Conversation Memory APIs](/docs/conversations/memory/api-quickstart.md): Learn more about authenticating and using the Conversation Memory APIs.
* [Conversation Memory concepts](/docs/conversations/memory/conversation-memory-concepts.md): Information about Conversation Memory's Recall endpoint and how observations are extracted.
* [Getting started with Conversation Memory](/docs/conversations/memory/getting-started.md): How to set up Conversation Memory in the Twilio Console.
* [Identity Resolution](/docs/conversations/memory/identity-resolution.md): Learn how Conversation Memory creates, matches, and merges customer profiles across channels using Identity Resolution.
* [Conversation Memory overview](/docs/conversations/memory.md): Learn how to use Conversation Memory to manage customer data and identity resolution across channels.
* [Conversation Memory key terms](/docs/conversations/memory/key-terms.md): Learn about customer profiles and the different data types associated with them.
* [Conversation Memory limits](/docs/conversations/memory/limits.md): Product and API resource limits for Conversation Memory.
* [Memory stores](/docs/conversations/memory/memory-stores.md): Learn when and why to create multiple memory stores versus reusing a single store for your customer data.
* [Memory observability logs](/docs/conversations/memory/observability-logs.md): Access and interpret Memory observability logs to troubleshoot your agent-based applications. Learn about event types, log schemas, and error handling.
* [Conversation Memory observability](/docs/conversations/memory/observability-overview.md): Monitor and debug Memory pipelines with structured event logging, error diagnostics, alerting, and traceability across the Twilio AI stack.
* [Memory observability traceability and lineage](/docs/conversations/memory/traceability-lineage.md): Use trace identifiers to monitor bulk profile imports, track lineage across the import pipeline, and debug issues down to individual profiles.

## Twilio Conversations (classic)

* [Twilio Conversations (classic)](/docs/conversations-classic.md): Build omni-channel messaging with Twilio Conversations (classic). Connect SMS, MMS, WhatsApp, and chat using the client SDKs and REST API for web and mobile apps.

## Twilio Email

* [Blocklist provider insights](/docs/email/concepts/deliverability/blocklist-provider-insights.md): Learn how major email blocklist providers, including Spamhaus, Proofpoint, SpamCop, and Microsoft, monitor IP addresses and how to request delisting.
* [Blocklists](/docs/email/concepts/deliverability/blocklists.md): Learn how email blocklists work, why senders get listed on them, and how to request delisting for shared and dedicated IP addresses with Twilio Email.
* [Deferrals](/docs/email/concepts/deliverability/deferrals.md): Learn about email deferrals, why messages are temporarily delayed by receiving servers, and how to address common causes.
* [Manage Unsubscribes](/docs/email/concepts/deliverability/unsubscribes.md): Set how you plan to manage recipients' requests to unsubscribe from your emails.
* [Apple iCloud](/docs/email/concepts/inbox-provider-insights/apple.md): Authentication requirements that Apple iCloud email services use.
* [Google](/docs/email/concepts/inbox-provider-insights/google.md): Authentication requirement that Gmail and Google-hosted email services use.
* [Inbox provider authentication requirements](/docs/email/concepts/inbox-provider-insights.md): Authentication requirements that popular inbox providers use.
* [Microsoft](/docs/email/concepts/inbox-provider-insights/microsoft.md): Authentication requirements that Microsoft Outlook and Microsoft 365 email services use.
* [Orange email security and reputation](/docs/email/concepts/inbox-provider-insights/orange.md): Authentication requirements that Orange email services use.
* [Yahoo](/docs/email/concepts/inbox-provider-insights/yahoo.md): Authentication requirements that Yahoo and Yahoo-served email services use.
* [Email concepts](/docs/email/concepts.md): Concepts cover the basics of bulk email messaging.
* [Establish and maintain reputation](/docs/email/concepts/reputation/establish-maintain-reputation.md): Give ISPs, inbox providers, and blocklist providers reasons to trust your email messages.
* [Spam notifications](/docs/email/concepts/reputation/spam-reports-and-fbls.md): Learn how Twilio Email uses inbox provider feedback loops (FBLs) to report spam complaints and help senders maintain a clean subscriber list.
* [Warm up an IP address](/docs/email/concepts/reputation/warm-up-ip-addresses.md): Learn how to warmup your new dedicated IP address and why it's important.
* [Abuse awareness](/docs/email/concepts/security/abuse-awareness.md): Learn how email attacks like phishing, cousin domains, snowshoeing, DKIM replay, and subscription bombing work and how senders can prevent them.
* [Email authentication](/docs/email/concepts/security/email-authentication.md): Learn how SPF, DKIM, and DMARC authenticate email through DNS records so inbox providers can trust messages sent from your domain.
* [Secure your Twilio account](/docs/email/concepts/security/secure-account.md): Secure your Twilio Email account and establish best security practices.
* [Encrypt with TLS](/docs/email/concepts/security/tls.md): Twilio uses Transport Layer Security when delivering email.
* [Twilio Email](/docs/email.md): Twilio Email lets you send transactional and marketing email with domain authentication, delivery tracking, and a scalable API.
* [Check email message delivery](/docs/email/logs.md): Twilio Email Logs record the delivery status of email messages that you send.
* [Authenticate email messages using DNS](/docs/email/security/domains.md): Set up domain authentication in Twilio Email so inbox providers can verify your messages originate from the domain in the sending email address.
* [Configure account settings](/docs/email/settings.md): Twilio Email Settings manage bounce and spam notifications, IP address restrictions, and exceptions to email suppressions.
* [Stop sending unwanted email](/docs/email/suppressions.md): Manage Twilio Email suppressions to stop sending to recipients who blocked, bounced, unsubscribed, reported spam, or have invalid email addresses.

## Twilio Labs

* [Twilio Dev Phone](/docs/labs/dev-phone.md): Learn how to install and use the Twilio Dev Phone to send and receive calls and SMS from your local development environment.
* [Twilio Labs](/docs/labs.md): Twilio Labs host a variety of open-source projects that were developed by people&#x20;
  at Twilio and the community. Every one of these projects welcomes contributions.

## Twilio Notify deprecated

* [Twilio Notify deprecated](/docs/notify.md): Twilio has deprecated Twilio Notify.

## Twilio Segment

* [Config API Overview](/docs/segment/api/config-api.md): Use the Config API to programmatically manage Segment workspaces, sources, destinations, and more.
* [Public API](/docs/segment/api/public-api.md): Use the Segment Public API to manage your Segment workspaces and their resources.
* [Delivery Overview](/docs/segment/connections/delivery-overview.md): Diagnose and resolve event delivery issues with Segment's Delivery Overview. Gain insights into your data pipeline using detailed visualizations to optimize performance.
* [Destination Actions](/docs/segment/connections/destinations/actions.md): Control data flow with Segment's Destination Actions, enabling transparent setup and customization for efficient event data management in destinations.
* [Destination Filters](/docs/segment/connections/destinations/destination-filters.md): Use Segment's destination filters to prevent certain data from flowing into a destination.
* [Destinations Overview](/docs/segment/connections/destinations.md): Act on real-time data with Segment Destinations. Explore compatible tools with our catalog, streamline analytics, and unlock customer insights instantly.
* [Destination Functions](/docs/segment/connections/functions/destination-functions.md): Use destination functions to transform and annotate Segment events and send them to external tools or APIs.
* [Functions Overview](/docs/segment/connections/functions.md): Streamline data flows by creating custom sources and destinations with Segment Functions. Transform, send, and enrich data using minimal code.
* [Destination Insert Functions](/docs/segment/connections/functions/insert-functions.md): Use Destination Insert Functions to transform and enrich your data before it reaches its destination. Customize logic, enhance compliance, and optimize data flow.
* [Source Functions](/docs/segment/connections/functions/source-functions.md): Use Segment Source Functions to collect, transform, and ingest data from any third-party app or webhook into Segment without managing infrastructure.
* [Transformation Functions](/docs/segment/connections/functions/transformation-functions.md): Use Segment Transformation Functions to enrich, transform, validate, or filter data anywhere within a journey.
* [Connections Overview](/docs/segment/connections.md): Collect and unify your customer data with Connections, which integrates with mobile apps, CRMs, and more for a holistic view.
* [Reverse ETL](/docs/segment/connections/reverse-etl.md): Reverse ETL syncs warehouse data to tools like Salesforce and Google Ads, empowering personalized marketing and enriched customer insights.
* [Set up Reverse ETL](/docs/segment/connections/reverse-etl/setup.md): Set up Reverse ETL in Segment by adding a source, building a model, connecting a destination, and creating mappings to sync warehouse data.
* [Analytics-Swift for iOS and Apple](/docs/segment/connections/sources/catalog/libraries/mobile/apple.md): Send data from iOS, tvOS, iPadOS, watchOS, macOS, and Linux apps to any analytics or marketing tool with the Analytics-Swift library for Swift and Objective-C.
* [HTTP API Source](/docs/segment/connections/sources/catalog/libraries/server/http-api.md): Use Segment HTTP API for seamless data collection from any site or app. Ensure efficient data routing with flexible, high performance and integration options.
* [Analytics for Node.js](/docs/segment/connections/sources/catalog/libraries/server/node.md): Use Segment's Analytics Node.js library to record analytics data from your Node code and route it to any destination, with tracking, plugins, and batching.
* [Analytics for Python](/docs/segment/connections/sources/catalog/libraries/server/python.md): Use Segment's Python library to record analytics data from your Python code.
* [Client-side persistence in Analytics.js](/docs/segment/connections/sources/catalog/libraries/website/javascript/cookie-validity-update.md): Learn about what data Analytics.js stores on the client and how to modify or override that storage behavior.
* [Self-Managed Custom Proxy](/docs/segment/connections/sources/catalog/libraries/website/javascript/custom-proxy.md): Set up a custom proxy for Analytics.js to track events through your own domain.
* [Managing identity in Analytics.js](/docs/segment/connections/sources/catalog/libraries/website/javascript/identity.md): Learn how Analytics.js manages user data by identifying, overriding, and refreshing \`userID\` and \`anonymousID\`, using settings in cookies and local storage.
* [Analytics.js Source](/docs/segment/connections/sources/catalog/libraries/website/javascript.md): Analytics.js API reference for tracking website data with Identify, Track, Page, Group, and Alias methods, plugins, batching, and retries in Segment.
* [Quickstart: Analytics.js](/docs/segment/connections/sources/catalog/libraries/website/javascript/quickstart.md): Learn how to send data from your website to Segment and any of Segment's destinations with Analytics.js.
* [Segment-Managed Custom Domain](/docs/segment/connections/sources/custom-domain.md): Enhance your data tracking with Custom Domain. Securely gather first-party data over HTTPS to boost user insights and maximize marketing ROI.
* [Sources Overview](/docs/segment/connections/sources.md): Create sources with Segment to efficiently track customer data from websites, apps, or servers. Enhance insights and control with targeted data collection.
* [Source Schema](/docs/segment/connections/sources/schema.md): Use Segment's Source Schema Controls to view, filter, and block events, properties, and traits before they reach your destinations and warehouses.
* [Spec: Alias](/docs/segment/connections/spec/alias.md): Merge unassociated user identities seamlessly using the Alias method, enhancing data connectivity and compatibility with downstream applications.
* [Best Practices for Identifying Users](/docs/segment/connections/spec/best-practices-identify.md): Maximize user insights with Segment's Identify and Track calls. Link actions to users, reduce costs, and enhance data accuracy.
* [Spec: Common fields](/docs/segment/connections/spec/common.md): Discover how API calls in Segment vary by destination and structure with specific fields. Learn to customize integrations and optimize data flow.
* [Spec: V2 Ecommerce Events](/docs/segment/connections/spec/ecommerce/v2.md): Gain insights into customer journeys with Segment's e-commerce spec. Track events from browsing to checkout, ensuring optimal e-commerce performance.
* [Spec: Group](/docs/segment/connections/spec/group.md): Associate users with groups using the Group API call. Manage user-group associations and update traits to tailor interactions.
* [Spec: Identify](/docs/segment/connections/spec/identify.md): Tie user actions to profiles using Segment's Identify call. Capture traits like email and User ID for personalized insights.
* [Spec Overview](/docs/segment/connections/spec.md): Learn more about the Segment Spec which provides guidance on meaningful data to capture, and the best format for it, across Segment's libraries and APIs.
* [Native Mobile Spec](/docs/segment/connections/spec/mobile.md): Enhance mobile analytics with Segment by using standard event names to optimize tracking and destination mapping.
* [What is the native mobile spec?](/docs/segment/connections/spec/native-mobile-spec.md): Discover how the Native Mobile Spec automates event tracking for mobile apps, reducing engineering time and enhancing campaign analysis.
* [Spec: Screen](/docs/segment/connections/spec/screen.md): Record user interactions on mobile screens with Segment's Screen call. Send screen details and properties for seamless app tracking and insights.
* [Spec: Track](/docs/segment/connections/spec/track.md): Use Segment's Track API to seamlessly capture and describe user actions with customizable events and properties, enhancing your analytics capabilities.
* [Warehouse FAQs](/docs/segment/connections/storage/warehouses/faq.md): Learn more about using warehouses with these frequently asked questions.
* [Data Warehouses](/docs/segment/connections/storage/warehouses.md): Discover how to choose and manage a data warehouse effectively, from understanding your data needs to optimizing SQL analysis and user permissions.
* [Warehouse Schemas](/docs/segment/connections/storage/warehouses/schema.md): Discover how Segment organizes and transforms your data into relational schemas for efficient querying in warehouses. Explore methods to optimize event data.
* [Testing connections](/docs/segment/connections/test-connections.md): Validate the connection between Segment and a destination using the Event Tester and Mappings Tester to inspect API requests, responses, and statuses.
* [Engage Audiences Overview](/docs/segment/engage/audiences.md): Use Engage Audiences to leverage events, traits, and APIs to sync across destinations, refine targeting, elevate engagement.
* [Linked Audiences](/docs/segment/engage/audiences/linked-audiences.md): Create targeted audiences with Linked Audiences to use behavioral and entity data in a no-code interface for precise marketing.
* [Event-Triggered Journeys](/docs/segment/engage/journeys/v2.md): Build responsive, real-time marketing workflows with Event-Triggered Journeys. Automate customer experiences upon specific actions for personalized engagement.
* [Using Engage Data](/docs/segment/engage/using-engage-data.md): Personalize messages and optimize ad spend by sending Computed Traits and Audiences to Segment Destinations. Discover how to activate Engage data.
* [How Segment works](/docs/segment/getting-started/01-what-is-segment.md): Learn how Segment works: sources collect customer data, Segment translates it, and destinations and warehouses receive the data in real time.
* [A Basic Segment Installation](/docs/segment/getting-started/02-simple-install.md): Walk through a basic Segment installation: create a source, find your write key, and install the JavaScript, iOS, or PHP library to send data.
* [A Full Segment Implementation](/docs/segment/getting-started/04-full-install.md): Discover Segment's six key tracking methods to streamline data collection and enhance consistency. Learn when and how to effectively apply each one.
* [Testing and Debugging](/docs/segment/getting-started/06-testing-debugging.md): Discover how to confirm Segment's functionality with tools like Source Debugger and Event Delivery. Monitor data flow and ensure successful event tracking.
* [Getting Started Guide](/docs/segment/getting-started/implementation-guide.md): Discover Segment's in-product guide, designed to streamline your data integration process, expand data reach, and optimize workspace efficiency.
* [What is Segment?](/docs/segment/getting-started.md): Segment collects first-party customer data from your websites, mobile apps, and servers, then sends it downstream to the business tools you use.
* [Filtering your Segment Data](/docs/segment/guides/filtering-data.md): Discover how to use Segment's data filtering options for precise control over event destinations.
* [An introduction to Segment](/docs/segment/guides.md): Discover how Segment simplifies customer data collection and integration. Unlock insights with seamless data management, unification, and personalized user experiences.
* [Segment for Developers](/docs/segment/guides/intro-impl.md): Get started with a Segment implementation. Learn the tracking API calls, message schemas, sources, destinations, and connection modes for developers.
* [MTUs, Throughput and Billing](/docs/segment/guides/usage-and-billing/mtus-and-throughput.md): Discover Segment's billing model with API calls, MTUs, and throughput. Understand usage insights, deduplication, and optimize third-party data integration.
* [Twilio Segment](/docs/segment.md): Twilio Segment is a customer data platform (CDP) that collects, cleans, and activates customer data, sending events to hundreds of tools with one API.
* [Configure Consent Management](/docs/segment/privacy/consent-management/configure-consent-management.md): Configure consent in Segment to enforce data preferences, ensuring user-approved event routing. Improve privacy compliance with precise category mapping.
* [Consent Management Overview](/docs/segment/privacy/consent-management.md): Streamline data consent with Segment's Consent Management feature. Enforce end-user consent preferences, ensuring compliance and optimized data flow.
* [Data Retention and Deletion Policy](/docs/segment/privacy/data-retention-policy.md): Discover how Segment's flexible billing and data retention model optimizes costs and ensures data security with clear retention policies for all customer tiers.
* [User Deletion and Suppression](/docs/segment/privacy/user-deletion-and-suppression.md): Ensure privacy compliance with Segment's data deletion and suppression tools.
* [Typewriter](/docs/segment/protocols/apis-and-extensions/typewriter.md): Boost your analytics with Typewriter. Generate type-safe Segment libraries from your Tracking Plan to improve accuracy and performance.
* [Data Collection Best Practices](/docs/segment/protocols/tracking-plan/best-practices.md): Maximize your app's success with our data tracking resources. Define objectives, standardize events, and improve insights for marketing and analytics teams.
* [Protocols Tracking Plan](/docs/segment/protocols/tracking-plan/create.md): Learn how to create a detailed Segment Tracking Plan to improve data accuracy across your sources.
* [Data Graph](/docs/segment/unify/data-graph.md): Discover insights with the Data Graph's semantic layer. Access relational datasets for personalized marketing without constant data team support.
* [Linked Events Overview](/docs/segment/unify/data-graph/linked-events.md): Enrich event streams with Linked Events, seamlessly integrating Snowflake, BigQuery, Redshift, or Databricks for richer data and optimized insights.
* [Identity Resolution Overview](/docs/segment/unify/identity-resolution.md): Learn more about how Identity Resolution merges customer histories into single profiles for real-time insights across all interactions.
* [Unify Overview](/docs/segment/unify.md): Use Unify to track and merge customer interactions into unified profiles. Enhance marketing with real-time insights and personalized experiences.
* [Profile API](/docs/segment/unify/profile-api.md): Use the Segment Profile API for real-time, personalized customer insights. Empower your apps with user-level data for enhanced engagement and sales.
* [Profiles Sync overview](/docs/segment/unify/profiles-sync/overview.md): Connect identity-resolved profiles to your data warehouse with Profiles Sync. Enrich data, analyze attribution, create models, and more.
* [Set up Profiles Sync](/docs/segment/unify/profiles-sync/profiles-sync-setup.md): Learn to set up Profiles Sync for connected data warehouses like Snowflake, Redshift, or BigQuery, enabling seamless historical backfill and sync control.
* [Profiles Sync Tables and Materialized Views](/docs/segment/unify/profiles-sync/tables.md): Discover how Segment's Profiles Sync enhances customer data integration with raw tables and materialized views, optimizing profile and event data management.
* [Unify Onboarding Guide](/docs/segment/unify/quickstart.md): Set up a Segment Unify space step by step, from creating a developer space and connecting sources to validating profiles and going to production.
* [Computed Traits](/docs/segment/unify/traits/computed-traits.md): Learn more about how computed traits help you to create user or account-level computations based on events and event properties.
* [Custom Traits](/docs/segment/unify/traits/custom-traits.md): Discover how to use Segment custom traits from Identify calls to enrich user profiles with demographics and account info without trait limits.
* [Predictions Nutrition Facts Label](/docs/segment/unify/traits/predictions/predictions-nutrition-facts.md): Review the AI Nutrition Facts label for Segment Predictions, covering the model type, data privacy level, data storage, and compliance details.
* [SQL Traits](/docs/segment/unify/traits/sql-traits.md): Import and manage SQL Traits in Segment for enhanced personalization. Leverage data from cloud sources to build audiences and meet your business goals.

## Twilio SendGrid

* [Add IPs](/docs/sendgrid/api-reference/account-ip-provisioning-api-ip-operations/add-ips.md): Add IP addresses to a customer account with the IP Provisioning API
* [List IPs](/docs/sendgrid/api-reference/account-ip-provisioning-api-ip-operations/list-ips.md): Retrieve a list of IP addresses associated with a customer account
* [Remove IPs](/docs/sendgrid/api-reference/account-ip-provisioning-api-ip-operations/remove-ips.md): Remove IP addresses from a customer account with the IP Provisioning API
* [Create Account](/docs/sendgrid/api-reference/account-provisioning-api-account-operations/create-account.md): Create a new customer account with the Twilio SendGrid Account Provisioning API by sending a profile object and an array of offerings in the request.
* [Delete Account](/docs/sendgrid/api-reference/account-provisioning-api-account-operations/delete-account.md): Delete an account under your organization with the Account Provisioning API
* [Account Provisioning API](/docs/sendgrid/api-reference/account-provisioning-api.md): The Twilio SendGrid Account Provisioning API provides a platform for Twilio SendGrid resellers to manage their customer accounts. This API is for companies that have a formal reseller partnership with Twilio SendGrid.
* [API Key permissions](/docs/sendgrid/api-reference/api-key-permissions.md): Utilize Twilio SendGrid API keys for secure and efficient access to v3 API endpoints. Manage different permissions for seamless integration.
* [Create API keys](/docs/sendgrid/api-reference/api-keys/create-api-keys.md): Manage and refine API keys using Twilio SendGrid App. Efficiently access SendGrid services with full control and scope for limited actions.
* [Delete API keys](/docs/sendgrid/api-reference/api-keys/delete-api-keys.md): Utilize API keys to validate access to SendGrid services without changing credentials. Manage actions with specific scopes via the Twilio SendGrid App.
* [Retrieve all bounces](/docs/sendgrid/api-reference/bounces-api/retrieve-all-bounces.md): Manage bounced emails and retrieve up to 500 instances per query with SendGrid's suppression settings in Twilio app, honing API parameters.
* [Add or update a contact](/docs/sendgrid/api-reference/contacts/add-or-update-a-contact.md): Use the SendGrid Marketing Campaigns API to add or update up to 30,000 contacts in a single PUT request, including custom fields and reserved fields.
* [Delete Contacts](/docs/sendgrid/api-reference/contacts/delete-contacts.md): Leverage the SendGrid API for bulk deleting of contacts. Ensure efficient contact management and avoid data loss with regular backups.
* [Import Contacts](/docs/sendgrid/api-reference/contacts/import-contacts.md): Use our API endpoint to import up to 1 million contacts via a CSV. Asynchronous process allows gzip compression and custom field mappings.
* [Contacts](/docs/sendgrid/api-reference/contacts.md): The Twilio SendGrid Marketing Campaigns Contacts API allows you to add, update, and delete contacts in your Marketing Campaigns account.
* [Create Design](/docs/sendgrid/api-reference/designs-api/create-design.md): Manage your email layouts with Twilio SendGrid's Designs API. Create, alter, or delete designs using a RESTful interface without UI dependency.
* [Authenticate a domain](/docs/sendgrid/api-reference/domain-authentication/authenticate-a-domain.md): Authenticating domains with SendGrid simplifies email sending. Enjoy personalized sender domains, managed SPF records, and automated or custom security options.
* [Domain Authentication](/docs/sendgrid/api-reference/domain-authentication.md): Authenticate sending domains with the Twilio SendGrid API. Create, list, update, and delete domain authentication records and manage subuser associations.
* [Validate a domain authentication](/docs/sendgrid/api-reference/domain-authentication/validate-a-domain-authentication.md): Authenticate your domain with SendGrid for email, eliminate 'via' or 'sent on behalf of' messages, and utilize your personal sending domain.
* [Download CSV](/docs/sendgrid/api-reference/email-activity/download-csv.md): Access Email Activity Feed API purchase extra email activity history for comprehensive message data analysis.
* [Filter all messages](/docs/sendgrid/api-reference/email-activity/filter-all-messages.md): Access and analyze your stored email messages using the Email Activity Feed API. Purchase additional history for enhanced data retrieval.
* [Filter messages by message ID](/docs/sendgrid/api-reference/email-activity/filter-messages-by-message-id.md): Use the Email Activity Feed API for efficient querying, downloading, and inspecting emails in Twilio SendGrid. Access bounced messages, sender/recipient details, event info, and more.
* [Email Activity](/docs/sendgrid/api-reference/email-activity.md): Use the Twilio SendGrid Email Activity Feed API to query, filter, and download your stored email message data, including rate limits and CSV export endpoints.
* [Request a CSV](/docs/sendgrid/api-reference/email-activity/request-a-csv.md): Harness the power of the Email Activity Feed API to analyze stored messages. Use the Twilio SendGrid App for email activity tracking.
* [Email Address Validation](/docs/sendgrid/api-reference/email-address-validation.md): Reduce bounce rate and improve your sender reputation by validating email addresses with the Email Address Validation API.
* [Request a Bulk Email Address Validation Upload URL](/docs/sendgrid/api-reference/email-address-validation/request-bulk-email-address-validation-upload-url.md): Request a presigned URL and headers to upload a CSV file for bulk email address validation with the Twilio SendGrid Email Address Validation API.
* [Real Time Email Address Validation - API Reference](/docs/sendgrid/api-reference/email-address-validation/validate-an-email.md): Integrate real-time Email Address Validation to your Twilio SendGrid App. Ensures validity, assesses bounce likelihood, identifies role/group accounts.
* [Filter all messages](/docs/sendgrid/api-reference/email-logs/filter-all-messages.md): Search stored email messages using the Email Logs API and return message-level results with key delivery attributes.
* [Filter messages by ID](/docs/sendgrid/api-reference/email-logs/filter-messages-by-id.md): Retrieve detailed event-level data for a specific message using the Email Logs API, including its delivery timeline and status updates.
* [Email Logs](/docs/sendgrid/api-reference/email-logs.md): Search and retrieve detailed email delivery and engagement data with the Email Logs API. Gain event-level visibility to troubleshoot and validate message outcomes in near real time.
* [Authentication](/docs/sendgrid/api-reference/how-to-use-the-sendgrid-v3-api/authentication.md): Explore the Twilio SendGrid Web API v3, a REST API with SDK support in seven languages. Ensure secure, controllable account access with API keys.
* [Authorization](/docs/sendgrid/api-reference/how-to-use-the-sendgrid-v3-api/authorization.md): Explore SendGrid's Web API v3, a RESTful API supporting seven languages, and learn to authenticate using API keys with specific scopes.
* [Errors](/docs/sendgrid/api-reference/how-to-use-the-sendgrid-v3-api/errors.md): Explore SendGrid's Web API v3: a fully featured, easily integratable RESTful API supporting 7 languages. Handles errors with detailed status codes.
* [How to use the SendGrid V3 API](/docs/sendgrid/api-reference/how-to-use-the-sendgrid-v3-api.md): Learn how to use the Twilio SendGrid Web API v3, a RESTful API with official libraries in 7 languages, including authentication, requests, and responses.
* [On Behalf Of](/docs/sendgrid/api-reference/how-to-use-the-sendgrid-v3-api/on-behalf-of.md): Utilize SendGrid's Web API v3, a user-friendly RESTful API; perform bulk actions and sub-account admin with the 'On Behalf Of' header.
* [Rate Limits](/docs/sendgrid/api-reference/how-to-use-the-sendgrid-v3-api/rate-limits.md): Explore SendGrid's Web API v3 features with this comprehensive guide. Understand rate limits, status codes, and more for efficient API calls.
* [Requests](/docs/sendgrid/api-reference/how-to-use-the-sendgrid-v3-api/requests.md): Leverage the power of SendGrid's Web API v3 for a multi-featured, RESTful API experience. Enable batch retrieval and search by field features.
* [Responses](/docs/sendgrid/api-reference/how-to-use-the-sendgrid-v3-api/responses.md): Explore the responses that the Twilio SendGrid Web API v3 returns.
* [SendGrid v3 API reference](/docs/sendgrid/api-reference.md): The SendGrid API reference provides detailed descriptions and code samples for every Twilio SendGrid API.
* [Errors](/docs/sendgrid/api-reference/mail-send/errors.md): Troubleshoot error code 400 during SendGrid API use. Explore solutions independently or engage Twilio SendGrid Support Team resources.
* [Mail Send API Overview](/docs/sendgrid/api-reference/mail-send.md): A high-level overview of the Mail Send endpoint in the SendGrid v3 Web API.
* [Mail Send](/docs/sendgrid/api-reference/mail-send/mail-send.md): Optimize emailing with SendGrid's Mail Send endpoint. Create dynamic templates, schedule emails, track click rates, and manage subscriptions efficiently.
* [SendGrid Engagement Quality API](/docs/sendgrid/api-reference/sendgrid-engagement-quality-api.md): Learn how the Twilio SendGrid Engagement Quality (SEQ) metric scores your email program and how to use the SEQ API to improve inbox placement.
* [Create a parse setting](/docs/sendgrid/api-reference/settings-inbound-parse/create-a-parse-setting.md): Set up Twilio SendGrid's Inbound Parse Webhook to receive emails at your desired URL. Configure domain, DNS, and API calls efficiently.
* [Settings - Inbound Parse](/docs/sendgrid/api-reference/settings-inbound-parse.md): Manage Twilio SendGrid Inbound Parse Webhook settings and security policies with the API to receive, parse, and secure inbound emails at your domains.
* [Settings - Tracking](/docs/sendgrid/api-reference/settings-tracking.md): Manage SendGrid tracking settings with the v3 API. Configure open tracking, click tracking, subscription tracking, and Google Analytics settings.
* [Create Single Send](/docs/sendgrid/api-reference/single-sends/create-single-send.md): Leverage your audience lists with Single Send API. Manage email messages for marketing campaigns, newsletters, legal notices, and more. No templates required.
* [Stats](/docs/sendgrid/api-reference/stats.md): Use the Twilio SendGrid Stats API to retrieve global and category email statistics, including open rates, click rates, bounces, and delivery metrics.
* [Retrieve global email statistics](/docs/sendgrid/api-reference/stats/retrieve-global-email-statistics.md): Track email activity efficiently using the Twilio SendGrid Stats API. Retrieve detailed global statistics like click rates, open rates, bounces, and more.
* [Suppressions - Unsubscribe Groups](/docs/sendgrid/api-reference/suppressions-unsubscribe-groups.md): Create and manage unsubscribe suppression groups with the Twilio SendGrid API to give recipients granular control over the emails they receive.
* [Create a transactional template.](/docs/sendgrid/api-reference/transactional-templates/create-a-transactional-template.md): Create HTML templates for transactional emails on SendGrid. Manage up to 300 unique templates per account, with dynamic content replacement.
* [Transactional Templates](/docs/sendgrid/api-reference/transactional-templates.md): Create and manage Twilio SendGrid transactional email templates with the API. Build, edit, duplicate, and retrieve up to 300 HTML templates per account.
* [Retrieve a single transactional template.](/docs/sendgrid/api-reference/transactional-templates/retrieve-a-single-transactional-template.md): Leverage an HTML template for creating transactional emails. Manage multiple transactional templates and efficiently fetch details using an endpoint.
* [Retrieve paged transactional templates.](/docs/sendgrid/api-reference/transactional-templates/retrieve-paged-transactional-templates.md): Discover how to create, retrieve and manage up to 300 unique transactional email templates with the easy-to-use API provided.
* [Create an Event Webhook](/docs/sendgrid/api-reference/webhooks/create-an-event-webhook.md): Create a Twilio SendGrid Event Webhook with a POST request to receive real-time email event notifications such as delivered, opened, clicked, and bounced.
* [Get All Event Webhooks](/docs/sendgrid/api-reference/webhooks/get-all-event-webhooks.md): List all Twilio SendGrid Event Webhooks for your account with a GET request to the v3 API. Retrieve every webhook's settings, IDs, and subscribed events.
* [Get an Event Webhook](/docs/sendgrid/api-reference/webhooks/get-an-event-webhook.md): Retrieve a single Event Webhook by its ID using the API endpoint at https://api.sendgrid.com. Detailed event data and settings returned efficiently.
* [Webhooks](/docs/sendgrid/api-reference/webhooks.md): Manage Twilio SendGrid Event Webhooks and Inbound Parse Webhooks with the v3 API. Create, retrieve, update, and delete webhook settings for your account or Subusers.
* [Test Event Notification Settings](/docs/sendgrid/api-reference/webhooks/test-event-notification-settings.md): Test Event Webhook on SendGrid using specialized endpoint. Facilitate POST requests, verify OAuth properties, and make API calls for subusers.
* [Blocklist provider insights](/docs/sendgrid/concepts/deliverability/blocklist-provider-insights.md): Discover how blocklist providers monitor and act on issues with IP addresses.
* [Blocklists](/docs/sendgrid/concepts/deliverability/blocklists.md): Learn how blocklists work, how you get on them, and how you get off them.
* [Deferrals](/docs/sendgrid/concepts/deliverability/deferrals.md): Learn about email deferrals, why messages are temporarily delayed by receiving servers, and how to address common causes.
* [Manage Unsubscribes](/docs/sendgrid/concepts/deliverability/unsubscribes.md): Set how you plan to manage recipients' requests to unsubscribe from your emails.
* [Email Flow](/docs/sendgrid/concepts/email-flow.md): Understand how an email message flows from sender to recipient inbox through SendGrid, including SMTP, DNS, authentication, reputation, and content checks.
* [Apple iCloud](/docs/sendgrid/concepts/inbox-provider-insights/apple.md): Authentication requirements that Apple iCloud email services use.
* [Google](/docs/sendgrid/concepts/inbox-provider-insights/google.md): Authentication requirement that Gmail and Google-hosted email services use.
* [Inbox provider authentication requirements](/docs/sendgrid/concepts/inbox-provider-insights.md): Compare how Apple, Google, Microsoft, Orange, and Yahoo handle email authentication, blocklists, and feedback loops, plus provider-specific sender services.
* [Microsoft](/docs/sendgrid/concepts/inbox-provider-insights/microsoft.md): Authentication requirements that Microsoft Outlook and Microsoft 365 email services use.
* [Orange email security and reputation](/docs/sendgrid/concepts/inbox-provider-insights/orange.md): Authentication requirements that Orange email services use.
* [Yahoo email authentication and reputation](/docs/sendgrid/concepts/inbox-provider-insights/yahoo.md): Authentication requirements that Yahoo and Yahoo-served email services use.
* [Email concepts](/docs/sendgrid/concepts.md): Concepts cover the basics of bulk email messaging.
* [Establish and maintain reputation](/docs/sendgrid/concepts/reputation/establish-maintain-reputation.md): Give ISPs, inbox providers, and blocklist providers reasons to trust your email messages.
* [Spam notifications](/docs/sendgrid/concepts/reputation/spam-reports-and-fbls.md): Learn how feedback loops (FBLs) report spam complaints to senders and how Twilio SendGrid enrolls users to monitor and act on those complaints.
* [Warm up an IP address](/docs/sendgrid/concepts/reputation/warm-up-ip-addresses.md): Learn how to warm up a new dedicated IP address, why gradual volume ramping matters, and how automated and manual IP warmup work in Twilio SendGrid.
* [Abuse awareness](/docs/sendgrid/concepts/security/abuse-awareness.md): Identify how email can be attacked.
* [Email authentication](/docs/sendgrid/concepts/security/email-authentication.md): Learn how SPF, DKIM, and DMARC authentication standards work together to verify your domain, prevent spoofing, and improve email deliverability.
* [Secure your Twilio account](/docs/sendgrid/concepts/security/secure-account.md): Secure your Twilio SendGrid account against takeovers with API key storage and rotation, IP access management, two-factor authentication, and SSO.
* [Encrypt with TLS](/docs/sendgrid/concepts/security/tls.md): Twilio uses Transport Layer Security when delivering email.
* [Twilio SendGrid developer documentation](/docs/sendgrid/for-developers.md): SendGrid's for-developers documentation provides information on how to use and configure SendGrid's APIs and developer-focused tools, including how to send email and configure your necessary DNS changes.
* [Migrate from Twilio SendGrid API v2 to v3](/docs/sendgrid/for-developers/migration-guides/v2-to-v3-api.md): Follow our guide to successfully migrate from SendGrid API v2 to v3. Improve performance and access updated features.
* [Inbound Email Parse Webhook](/docs/sendgrid/for-developers/parsing-email/inbound-email.md): Utilize SendGrid's Parse API to parse incoming emails and attachments efficiently. Mitigate data loss and ensure email delivery success.
* [Configure the inbound parse webhook](/docs/sendgrid/for-developers/parsing-email/setting-up-the-inbound-parse-webhook.md): How to set up the inbound parse webhook to process and parse incoming email
* [Migrating from a partner account](/docs/sendgrid/for-developers/partners/account-migration.md): How to migrate from a Twilio SendGrid partner account to a direct SendGrid account, including sender authentication, unsubscribes, templates, IPs, and subusers.
* [Sending Email with Microsoft Azure](/docs/sendgrid/for-developers/partners/microsoft-azure-2021.md): Create and configure a Twilio SendGrid account through the Microsoft Azure Marketplace, then set up 2FA, API keys, and Sender Authentication to send email.
* [Getting started with the SendGrid API](/docs/sendgrid/for-developers/sending-email/api-getting-started.md): Sending your first email using the SendGrid REST API.
* [Authentication](/docs/sendgrid/for-developers/sending-email/authentication.md): Authenticating with the Twilio SendGrid API.
* [Automate Adding Subusers with the SendGrid API](/docs/sendgrid/for-developers/sending-email/automating-subusers.md): Use the SendGrid API to add Subusers to your account.
* [Building an X-SMTPAPI Header](/docs/sendgrid/for-developers/sending-email/building-an-x-smtpapi-header.md): Learn how to build email content, add recipients and schedule your send.
* [Working with Categories](/docs/sendgrid/for-developers/sending-email/categories.md): Learn how to utilize SendGrid's PII fields, improve email analytics, categorize emails, and understand category limits effectively.
* [Cross Origin Resource Sharing (CORS)](/docs/sendgrid/for-developers/sending-email/cors.md): CORS is a security feature of modern browsers to keep browser users secure.
* [cURL Examples for Common Use Cases](/docs/sendgrid/for-developers/sending-email/curl-examples.md): Schedule or cancel emails effectively within a 72-hour timeframe using the send\_at parameter and Cancel Scheduled Sends endpoint.
* [Django](/docs/sendgrid/for-developers/sending-email/django.md): View instructions on how to send email with Django using SendGrid, by setting up setting up Django's built in mail library.
* [Email API Quickstart for C#](/docs/sendgrid/for-developers/sending-email/email-api-quickstart-for-c.md): Learn to send emails using Twilio SendGrid Mail Send API and C# with our comprehensive guide. Master setup, installation, and code development.
* [Email API Quickstart for Java](/docs/sendgrid/for-developers/sending-email/email-quickstart-for-java.md): Send emails easily with SendGrid's Mail Send API and Java following this quickstart guide. Covers setup, sending, and troubleshooting.
* [Enforced TLS](/docs/sendgrid/for-developers/sending-email/enforced-tls.md): Learn to retrieve or update Enforced TLS settings using our provided endpoints. Ensure recipients support TLS 1.1 or above.
* [Getting Started with the Email Activity Feed API](/docs/sendgrid/for-developers/sending-email/getting-started-email-activity-api.md): Use the Email Activity Feed query language to get started with the Email Activity Feed API.
* [How to send an Email with SMTP](/docs/sendgrid/for-developers/sending-email/getting-started-smtp.md): Use Telnet to send your first SMTP email. SendGrid's software allows developers to specify custom handling instructions for email using an X-SMTPAPI header inserted into the message.
* [Getting Started with Transactional Email](/docs/sendgrid/for-developers/sending-email/getting-started-with-transactional-emails.md): Send transactional email with Twilio SendGrid over SMTP or the Mail Send API, including receipts, password resets, and account notifications.
* [How to Create a Subuser with the API](/docs/sendgrid/for-developers/sending-email/how-to-create-a-subuser-with-the-api.md): Create a SendGrid subuser using only API calls. Establish the account, assign an IP, set domain authentication, and enable website and SMTP access.
* [Integrating with the SMTP API](/docs/sendgrid/for-developers/sending-email/integrating-with-the-smtp-api.md): Learn how to set your systems up to use SendGrid's SMTP API to integrate and send emails.
* [Send Email in Laravel](/docs/sendgrid/for-developers/sending-email/laravel.md): Send email with Laravel using SendGrid over SMTP. Configure your .env file, create a Mailable class, and add categories or custom fields.
* [API Libraries](/docs/sendgrid/for-developers/sending-email/libraries.md): Send email and interact with SendGrid using your favorite language including Python, Go, Node.js, Ruby, PHP, Java, C#, Perl, Objective-C, and more.
* [Personalizations](/docs/sendgrid/for-developers/sending-email/personalizations.md): Learn how to use personalizations to customize your messages sent over the Web API v3.
* [Postfix](/docs/sendgrid/for-developers/sending-email/postfix.md): Setup SendGrid as a Postfix relay host for better deliverability and advanced statistics on your email.
* [Email API Quickstart for Go](/docs/sendgrid/for-developers/sending-email/quickstart-go.md): Send your first email with Go using the Twilio SendGrid Mail Send API and the sendgrid-go SDK. Includes setup, API key, sender verification, and code.
* [Email API Quickstart for Node.js](/docs/sendgrid/for-developers/sending-email/quickstart-nodejs.md): Send your first email with Node.js using the Twilio SendGrid Mail Send API and the @sendgrid/mail SDK. Includes setup, API key, sender verification, and code.
* [Email API Quickstart for PHP](/docs/sendgrid/for-developers/sending-email/quickstart-php.md): Send your first email with PHP using the Twilio SendGrid Mail Send API and the sendgrid-php SDK. Includes setup, API key, sender verification, and code.
* [Email API Quickstart: How to Send Email with Python](/docs/sendgrid/for-developers/sending-email/quickstart-python.md): Sending your first email using the SendGrid REST API and Python.
* [Email API Quickstart for Ruby](/docs/sendgrid/for-developers/sending-email/quickstart-ruby.md): Sending your first email using the SendGrid REST API and Ruby.
* [Ruby on Rails](/docs/sendgrid/for-developers/sending-email/rubyonrails.md): View instructions on how to easily send email with Ruby on Rails using SendGrid, by setting up setting up ActionMailer or using a gem.
* [Sandbox Mode](/docs/sendgrid/for-developers/sending-email/sandbox-mode.md): Learn how to use Sandbox Mode when sending mail over SendGrid's Web API v3.
* [Scheduling Email](/docs/sendgrid/for-developers/sending-email/scheduling-email.md): How can I schedule emails to send at specific times?
* [Segmentation Query Language Reference](/docs/sendgrid/for-developers/sending-email/segmentation-query-language.md): SendGrid Segmentation Query Language Reference
* [Sender Identity](/docs/sendgrid/for-developers/sending-email/sender-identity.md): Understanding the difference between Domain Authentication and verifying a Single Sender.
* [Single Sends 2020 Update](/docs/sendgrid/for-developers/sending-email/single-sends-2020-update.md): Instructions for migrating to the updated Single Sends API
* [SMTP Errors and Troubleshooting](/docs/sendgrid/for-developers/sending-email/smtp-errors-and-troubleshooting.md): SMTP Response codes and troubleshooting tips
* [Stopping an in-progress send](/docs/sendgrid/for-developers/sending-email/stopping-an-in-progress-send.md): Stop a Twilio SendGrid email send in progress by changing your API key, contacting Support, or canceling a marketing campaign in the UI or API.
* [Substitution Tags](/docs/sendgrid/for-developers/sending-email/substitution-tags.md): Substitution tags let you insert dynamic, per-recipient content into Twilio SendGrid SMTP API emails, such as names, custom URLs, and other values.
* [Support for TLS 1.2](/docs/sendgrid/for-developers/sending-email/support-for-tls-12.md): Twilio SendGrid ends support for TLS 1.0 and TLS 1.1. Learn how to test your infrastructure to ensure that you are supporting TLS 1.2 or higher.
* [Unique Arguments](/docs/sendgrid/for-developers/sending-email/unique-arguments.md): Add unique arguments to customize your SMTP emails event tracking
* [Upgrade your authentication method to API keys](/docs/sendgrid/for-developers/sending-email/upgrade-your-authentication-method-to-api-keys.md): How to upgrade your authentication methods in your code to use API keys
* [Using Handlebars](/docs/sendgrid/for-developers/sending-email/using-handlebars.md): Utilize Twilio's SendGrid Dynamic Transactional Templates and Marketing Campaigns for seamless message personalizations and efficient data integration.
* [v3 API C# Code Example](/docs/sendgrid/for-developers/sending-email/v3-csharp-code-example.md): Integrate effortlessly with SendGrid C#, a fully documented client library on GitHub. An API Key is essential for integration.
* [v3 API Java Code Example](/docs/sendgrid/for-developers/sending-email/v3-java-code-example.md): Integrate SendGrid Java with your system, access the client library on GitHub. Use an API Key for seamless integration.
* [v3 Mail Send FAQ](/docs/sendgrid/for-developers/sending-email/v3-mail-send-faq.md): Leverage SendGrid's v3 Mail Send, the improved Web API endpoint, for effective email management. Enhanced JSON schema, better validation, and easy migration.
* [v3 API Python Code Example](/docs/sendgrid/for-developers/sending-email/v3-python-code-example.md): Integrate Twilio SendGrid using the Python client library with complete documentation. Detailed example with API integration tips and resources.
* [Web API vs. SMTP for Sending Email](/docs/sendgrid/for-developers/sending-email/web-api-vs-smtp.md): Compare the Twilio SendGrid Web API and SMTP relay for sending email. Learn how each method works, their differences, and which option fits your use case.
* [Event Webhook C# Code Example](/docs/sendgrid/for-developers/tracking-events/csharp-code-example.md): Implement email parsing from the SendGrid domain and post to a specific URL using our proven methods in ApiController.
* [Event Webhook Reference](/docs/sendgrid/for-developers/tracking-events/event.md): Full Event Webhook event list and descriptions, event examples, and the objects each event contains.
* [Getting Started with the Event Webhook Security Features](/docs/sendgrid/for-developers/tracking-events/getting-started-event-webhook-security-features.md): Secure the Event Webhook using the Signed Webhook, OAuth 2.0, or both.
* [Getting started with the Event Webhook](/docs/sendgrid/for-developers/tracking-events/getting-started-event-webhook.md): Add and configure a Twilio SendGrid Event Webhook to post email event data to your URL, including local testing with ngrok and webhook testing sites.
* [Event Webhook Node.js Code Example](/docs/sendgrid/for-developers/tracking-events/nodejs-code-example.md): Explore how to parse emails using Node and Express, and post via Event Webhook. The sendgrid.biz/parse guide simplifies the process.
* [Twilio SendGrid Event Webhook Overview](/docs/sendgrid/for-developers/tracking-events/twilio-sendgrid-event-webhook-overview.md): Understand the SendGrid Event Webhook and how to integrate it to better manage your email program with event data.
* [Ad exchange](/docs/sendgrid/glossary/ad-exchange.md): \*Advertising\*. A digital marketplace where advertisers and publishers can buy and sell display, video, and mobile advertising.
* [Ad impression](/docs/sendgrid/glossary/ad-impression.md): \*Advertising\*. One occurence of an advertisement displaying on a screen.
* [Ad unit](/docs/sendgrid/glossary/ad-unit.md): \*Advertising\*. The container that holds the advertising copy and graphics for a digital advertisement on a screen.
* [Affiliate marketing](/docs/sendgrid/glossary/affiliate-marketing.md): \*Marketing\*. An activity in which companies offer to pay individuals or other businesses to promote their products or services.
* [Affirmative consent](/docs/sendgrid/glossary/affirmative-consent.md): \*Reputation\*. The informed, explicit acceptance that a recipient granted you to receive your email.
* [Allowlist](/docs/sendgrid/glossary/allow-list.md): \*Internet Security\*. A curated selection of domains, email addresses, or IP addresses that a service or system has granted explicit access.
* [Automated email](/docs/sendgrid/glossary/automated-email.md): \*Marketing\*. A system that allows the sending of messages with content relevant to individual recipients.
* [Autoresponder](/docs/sendgrid/glossary/autoresponder.md): \*Marketing\*. A system that generates email responses to actions and events.
* [Bayesian filter](/docs/sendgrid/glossary/bayesian-filter.md): \*Email Deliverability\*. A statistical technique that detects email spam.
* [Blocklist](/docs/sendgrid/glossary/blocklist.md): \*Email Deliverability\*. A list of IP addresses, email addresses, or domains known to ISPs or list providers for sending unsolicited or unwanted emails.
* [Blocked email messages](/docs/sendgrid/glossary/blocks.md): \*Email Deliverability\*. A temporary rejection of messages sent from your IP address.
* [Bounced email messages](/docs/sendgrid/glossary/bounces.md): \*Email Deliverability\*. A permanent rejection of messages sent from your IP address.
* [Bulk email service](/docs/sendgrid/glossary/bulk-email-service.md): \*Marketing\*. Software or service through which one sender can send one or many email messages to a large list of recipients.
* [Bulk mail folder](/docs/sendgrid/glossary/bulk-mail-folder.md): \*Email Deliverability\*. A location in a recipient's inbox into which the inbox provider routes email of questionable use or providence.
* [Campaigns](/docs/sendgrid/glossary/campaigns.md): \*Marketing\*. The act of sending customized email messages to a group of targeted recipient segments.
* [CAN-SPAM Act of 2003](/docs/sendgrid/glossary/can-spam.md): \*Regulation\*. US law that lists the guidelines, requirements, and penalties regarding the sending of commercial bulk email.
* [Canonicalization](/docs/sendgrid/glossary/canonicalization.md): \*Internet standard\*. The standardization of email messages formatting that enables consistent hashed values for validating email messages.
* [Canadian Anti-Spam Law of 2014](/docs/sendgrid/glossary/casl.md): \*Regulation\*. Canadian law that lists the guidelines, requirements, and penalties regarding the sending of commercial bulk email.
* [Categories](/docs/sendgrid/glossary/categories.md): \*Analytics\*. One or more topical tags applied to an email message that aids in analyzing email campaign effectiveness.&#x20;
* [Content delivery network](/docs/sendgrid/glossary/cdn.md): \*Service Provider\*. A global network of servers that stores and serves copies of website content to website visitors using the server geographically closest to each website visitor.&#x20;
* [Challenge-response spam filtering](/docs/sendgrid/glossary/challenge-response.md): \*Internet Security\*. A type of spam filter that replies with a challenge to the given sender.
* [Clicks and unique clicks](/docs/sendgrid/glossary/clicks.md): \*Analytics\*. A record of each time a customer clicks any link in your Twilio SendGrid emails.
* [Canonical Name record (CNAME)](/docs/sendgrid/glossary/cname.md): \*Internet standard\*. A DNS record that maps one hostname in a domain to another hostname instead of an IP address.
* [Complaint](/docs/sendgrid/glossary/complaint.md): \*Reputation\*. A record of an email recipient reporting an email message as spam.
* [Click-through rate](/docs/sendgrid/glossary/ctr.md): \*Analytics\*. A metric of interest in content linked in an email message expressed as a percentage of recipients that click a link in your email message.
* [Custom fields](/docs/sendgrid/glossary/custom-fields.md): \*Configuration\*. Original contact attribute added to your email contacts.
* [Deferral](/docs/sendgrid/glossary/deferrals.md): \*Email Deliverability\*. A deferred status can occur when an ISP or mailbox provider can't accept email from your IP address.
* [Deliverability](/docs/sendgrid/glossary/deliverability.md): \*Email Deliverability\*. The measure of how many emails sent that reach their intended recipients without issue.
* [Delivery](/docs/sendgrid/glossary/deliveries.md): \*Email Deliverability\*. A confirmation that an end recipient received the email that the sender had sent.
* [Demand-side platform (DSP)](/docs/sendgrid/glossary/demand-side-platform.md): \*Advertising\*. Software that helps advertisers or ad agencies buy digital ad inventory across publishers, supply-side platforms, and ad exchanges.
* [Direct response advertising](/docs/sendgrid/glossary/direct-response-advertising.md): \*Advertising\*. A advertising tactic where ad content encourages or prompts viewers of an ad to act or to engage with the ad directly.
* [DomainKeys Identified Mail (DKIM)](/docs/sendgrid/glossary/dkim.md): \*Internet standard\*. DomainKeys Identified Mail (DKIM) is a domain-based email authentication protocol that helps mailbox providers identify legitimate email senders.
* [Domain-based Message Authentication, Reporting and Conformance (DMARC)](/docs/sendgrid/glossary/dmarc.md): \*Internet Security\*, \*Internet Standard\*. A domain-based policy for determining the authenticity of the person or service sending email on behalf of a domain.
* [Domain Name System](/docs/sendgrid/glossary/dns.md): \*Internet standard\*. A hierarchical system of software and systems that translate a fully qualified domain name into an IP address.
* [Domain authentication](/docs/sendgrid/glossary/domain-authentication.md): \*Internet Security\*. Protocols and policies that specify IP addresses and domains as proof of identity of an individual or organization sending email messages.
* [Domain](/docs/sendgrid/glossary/domain.md): \*Internet standard\*. A human-readable branding for an individual or organization's presense on the internet.
* [Drip campaign](/docs/sendgrid/glossary/drip-campaign.md): \*Marketing\*. An email marketing strategy that sends engagement email messages on a schedule.
* [Drops](/docs/sendgrid/glossary/drops.md): \*Email Deliverability\*. The removal of an email message to a specific recipient to protect the sender's reputation.
* [Email API integration](/docs/sendgrid/glossary/email-api-integration.md): \*API\*. The facilitation of automating key functions through the synchronization of a sender's email service provider with their platform and software tools.
* [Email Authentication](/docs/sendgrid/glossary/email-authentication.md): \*Internet Security\*. Technical standards to help ISPs and other receivers validate the identity of an email sender.
* [Email harvesting](/docs/sendgrid/glossary/email-harvesting.md): \*Reputation\*. The process of obtaining lists of valid email addresses other than affirmative consent of the recipients for the purpose of sending bulk email.
* [Email marketing](/docs/sendgrid/glossary/email-marketing.md): \*Marketing\*. The promotion of a commercial product or service conveyed in an email message.
* [Email reputation score](/docs/sendgrid/glossary/email-reputation-score.md): \*Reputation\*. The rating an internet service provider or inbox provider sets for email sent from your email server IP addresses.
* [Email service provider (ESP)](/docs/sendgrid/glossary/email-service-provider.md): \*Service Provider\*. A service organization that provides transactional and marketing email services.
* [Expandable Banner](/docs/sendgrid/glossary/expandable-banner.md): \*Advertising\*. A design of a digital advertisement that increases in size when a viewer clicks or hovers over the ad.
* [Expired](/docs/sendgrid/glossary/expired.md): \*Email Deliverability\*. The removal of recipient email address from a contact list when an SMTP server couldn't deliver an email message to the recipient within 72 hours.
* [Feedback loop](/docs/sendgrid/glossary/feedback-loop.md): \*Reputation\*. A process where an service provider forwards emails reported as spam to a sender for removal.
* [Flighting](/docs/sendgrid/glossary/flighting-in-advertising.md): \*Advertising\*. The time in which an advertising campaign runs.
* [Fully Qualified Domain Name (FQDN)](/docs/sendgrid/glossary/fqdn.md): \*Internet standard\*. A human-readable label that identifies a specific server on the internet.
* [Frequency capping](/docs/sendgrid/glossary/frequency-capping.md): \*Advertising\*. The setting of a maximum number of times a specific viewer sees a specific ad.&#x20;
* [General Data Protection Regulation of 2018](/docs/sendgrid/glossary/gdpr.md): \*Regulation\*. European Union law that regulates the handling of personal data and outlines the rights individuals have regarding their data.
* [Header](/docs/sendgrid/glossary/header.md): \*Internet standard\*. Metadata that informs email recipients and servers of the routing, formatting, and security of an email message.
* [Internet Message Access Protocol (IMAP)](/docs/sendgrid/glossary/imap.md): \*Internet standard\*. The communication rules that systems follow to let you read and retrieve email messages from your inbox provider.
* [SendGrid Glossary](/docs/sendgrid/glossary.md): A repository of the technical terms and jargon that intrepid Twilio SendGrid developers may encounter on their building journey.
* [Invalid Email](/docs/sendgrid/glossary/invalid-email.md): Email Deliverability. An invalid email is a recipient address that doesn't conform to IETF email syntax standards and is removed from a contact list.
* [IP Address](/docs/sendgrid/glossary/ip-address.md): \*Internet standard\*. A unique numerical address that identifies a virtual location on the internet.
* [IP address warmup](/docs/sendgrid/glossary/ip-warmup.md): \*Email Deliverability\*. The establishment of a reputation as a legitimate email sender through the gradual and regular increase in the volume of email sent from one IP address.
* [Link branding](/docs/sendgrid/glossary/link-branding.md): \*Marketing\*. Change the domain for open and click tracking links to your domain.
* [Lists](/docs/sendgrid/glossary/lists.md): \*Marketing\*. Static collections of contacts to whom email messages can be sent.
* [Mail merge](/docs/sendgrid/glossary/mail-merge.md): \*Marketing\*. A process that generates customized email messages from a generic template and store of contact data.
* [Mailbox provider](/docs/sendgrid/glossary/mailbox-provider.md): \*Marketing\*. A service organization that provides transactional email services, marketing email services, or both.
* [Twilio SendGrid message ID](/docs/sendgrid/glossary/message-id.md): \*Marketing\*. A unique identifier that Twilio SendGrid generates and assigns to an email message for event identification purposes.
* [Mail Transfer Agent (MTA)](/docs/sendgrid/glossary/mta.md): \*Internet standard\*. A system that transfers email messages from one computer to another using a client-server application architecture.
* [Mail User Agent (MUA)](/docs/sendgrid/glossary/mua.md): \*Internet standard\*. An app that you use to compose and send email messages.
* [Mail Exchanger record (MX)](/docs/sendgrid/glossary/mx-record.md): \*Internet standard\*. A DNS record that maps the hostname in a domain that accepts email for the domain.
* [Native advertising](/docs/sendgrid/glossary/native-advertising.md): \*Advertising\*. A type of advertising that resembles the content of the surrounding medium.
* [Open Rate](/docs/sendgrid/glossary/open-rate.md): \*Analytics\*. The frequency by which your customers open emails that you send.
* [Open relay](/docs/sendgrid/glossary/openrelay.md): \*Internet Security\*. An unsecured SMTP relay that routes email between domains.
* [Opens & Unique Opens](/docs/sendgrid/glossary/opens.md): \*Analytics\*. The record of each time a customer opens your Twilio SendGrid email messages.
* [Peer-initiated invitations campaign](/docs/sendgrid/glossary/peer-invitations.md): \*Marketing\*. A email marketing campaign designed to get customers to invite their friends and family.
* [Phishing](/docs/sendgrid/glossary/phishing.md): \*Internet Security\*. The act of masquerading as a trusted business to acquire personally identifiable information.
* [Preheader](/docs/sendgrid/glossary/preheader.md): \*Marketing\*. The short summary text that follows the subject line when you view an email in your inbox.
* [Programmatic media buying](/docs/sendgrid/glossary/programmatic-media-buying.md): \*Advertising\*. Process of buying paid media through sophisticated software that automates how the buying, placing, and optimizing of paid media.
* [Pointer record (PTR)](/docs/sendgrid/glossary/ptr.md): \*Internet standard\*. A DNS record that maps an IP address to one hostname in a domain.
* [Rate limiting](/docs/sendgrid/glossary/rate-limiting.md): \*Email Deliverability\*. See Throttling.
* [Reconfirmation email](/docs/sendgrid/glossary/reconfirmation.md): \*Reputation\*. An email message sent to existing recipients asking them to confirm that they still want your messages.
* [Request](/docs/sendgrid/glossary/request.md): \*Analytics\*. The record of an attempt to send an email through Twilio SendGrid.
* [Reseller email account](/docs/sendgrid/glossary/reseller-email-account.md): \*Service Provider\*. Email account created after a company entered into a partnership with Twilio.
* [Reserved fields](/docs/sendgrid/glossary/reserved-fields.md): \*Configuration\*. Predefined and protected attributes provided for email contacts.
* [Reverse DNS](/docs/sendgrid/glossary/reverse-dns.md): \*Internet Standard\*. Method for systems to resolve an IP address from a domain name.
* [Scheduled Emails](/docs/sendgrid/glossary/scheduled-emails.md): \*Marketing\*. Configuring a system to send email messages starting at a given date and time.
* [Segmentation](/docs/sendgrid/glossary/segmentation.md): \*Marketing\*. The practice of channeling email traffic based on the intent and audience of email messages.
* [Segments](/docs/sendgrid/glossary/segments.md): \*Marketing\*. A dynamic collection of contacts grouped based on criteria you define.
* [Sender authentication](/docs/sendgrid/glossary/sender-authentication.md): \*Internet Security\*. The process that shows ISPs that you gave your mailbox provider permission to send emails on your behalf.
* [Sender ID](/docs/sendgrid/glossary/sender-id.md): \*Internet Security\*. A deprecated email authentication standard that checked that a domain authorized a given email address to send on its behalf.
* [Senders](/docs/sendgrid/glossary/senders.md): Identity of the individual, position, or organization sending an email message.
* [Sends](/docs/sendgrid/glossary/sends.md): \*Analytics\*. A request for Twilio SendGrid to deliver email to your recipients.
* [Single send](/docs/sendgrid/glossary/single-send.md): \*Marketing\*. A non-recurring email message that communicates non-automated, non-sequential content.
* [SMTP API](/docs/sendgrid/glossary/smtp-api.md): \*API\*. A progamming interface that provides customized email handling instructions on a per-email basis.
* [SMTP Provider](/docs/sendgrid/glossary/smtp-provider.md): \*Service Provider\*. A vendor that helps send large quantities of email messages to recipients.
* [SMTP relay](/docs/sendgrid/glossary/smtp-relay.md): \*Internet standard\*. A system that sends email between SMTP servers on different domains.
* [SMTP Server](/docs/sendgrid/glossary/smtp-server.md): \*Internet standard\*. An app or server that sends email and reacts to response codes from receiving servers.
* [SMTP service](/docs/sendgrid/glossary/smtp-service.md): \*Email Deliverability\*. Third-party managed service that delivers email messages to a large audience.
* [Simple Mail Transfer Protocol (SMTP)](/docs/sendgrid/glossary/smtp.md): \*Internet standard\*. The communication rules that systems follow for the reliable and efficient transfer of email messages.
* [Spam Filter](/docs/sendgrid/glossary/spam-filter.md): \*Email Deliverability\*. Algorithms that identify and remediate unwanted email messages.
* [Spam report](/docs/sendgrid/glossary/spam-reports.md): \*Reputation\*. A feedback mechanism that identifies electronic messages as abusing the transmission medium and reports them to an authority for remediation.
* [Spam Traps](/docs/sendgrid/glossary/spam-traps.md): \*Reputation\*. Email addresses created without active owners to identify spammers and senders with poor data quality practices.
* [Spam](/docs/sendgrid/glossary/spam.md): \*Reputation\*. An email message sent to a recipient that they didn't request or want.
* [Sender Policy Framework (SPF)](/docs/sendgrid/glossary/spf.md): \*Internet Security\*, \*Internet Standard\*. An email authentication standard that sets which servers can send email from their domain.
* [Spoofing](/docs/sendgrid/glossary/spoofing.md): \*Internet Security\*. A technique where a falsified sender email addresses attempts to trick recipients into opening an email message.
* [Subscriber list management](/docs/sendgrid/glossary/subscriber-list-management.md): \*Marketing\*. The validation that subscribers found in your contact lists remain active and engaged with your email marketing.
* [Suspicious Sender](/docs/sendgrid/glossary/suspicious-sender.md): \*Reputation\*. An email sender who sends email messages to recipients that never granted explicit permission to that sender.
* [Reserved substitution tags](/docs/sendgrid/glossary/system-fields.md): \*Configuration\*. Placeholder labels that get replaced with personalized content in an email campaign.
* [Teammates](/docs/sendgrid/glossary/teammates.md): \*Configuration\*. Option that allows multiple physical users to share access to a single Twilio SendGrid account.
* [Throttling](/docs/sendgrid/glossary/throttling.md): \*Email Deliverability\*. A recipient inbox provider reduces throughput of email messages below the level at which sender mail server sent the email messages.
* [Time zone](/docs/sendgrid/glossary/timezone.md): \*Internet standard\*. Local time, based on your current geographic location on the earth.
* [Transport Layer Security (TLS)](/docs/sendgrid/glossary/tls.md): \*Internet Security\*, \*Internet Standard\*. The set of rules that encrypts internet traffic between systems.
* [Transactional Email Templates](/docs/sendgrid/glossary/transactional-email-templates.md): \*Marketing\*. A predesigned email layout, and sometimes content, that you can apply to transactional emails.
* [Transactional email](/docs/sendgrid/glossary/transactional-email.md): \*Marketing\*. An email message sent in response to a user interaction with a web application.
* [Triggered action](/docs/sendgrid/glossary/triggered-actions.md): \*Marketing\*. A task executed once a customer meets a pre-defined condition.
* [Triggered email](/docs/sendgrid/glossary/triggered-email.md): \*Marketing\*. An email message sent in response to specific events or actions.
* [Trusted sender](/docs/sendgrid/glossary/trusted-sender.md): \*Reputation\*. An email sender who only sends email messages to those recipients that granted explicit permission to that sender.
* [Two Factor Authentication (2FA)](/docs/sendgrid/glossary/two-factor-authentication.md): \*Internet Security\*. Use of two or more means of user identification to grant access to a system.
* [Undelivered Email](/docs/sendgrid/glossary/undelivered-email.md): \*Email Deliverability\*. A category of reasons why an email message wasn't delivered to a recipient's inbox.
* [Unknown User](/docs/sendgrid/glossary/unknown-user.md): \*Email Deliverability\*. A bounce reason indicating that the recipient email address doesn't exist on the recipient email server.
* [Unsubscribe](/docs/sendgrid/glossary/unsubscribes.md): \*Email Deliverability\*. A recipient's voluntary decision to remove themself from a sender's bulk email service.
* [Urchin Tracking Module (UTM) parameters](/docs/sendgrid/glossary/utm-parameters.md): \*Analytics\*. Five URL parameters added to links that marketers use to track online marketing campaigns.
* [Web API](/docs/sendgrid/glossary/web-api.md): \*API\*. A programming interface that allows web servers and web browsers to connect and enable account and data collection for services like email.
* [Webhook](/docs/sendgrid/glossary/webhook.md): \*Analytics\*. An event-driven communication that sends data between apps using custom HTTP POST request to a URL.
* [X-Message-ID](/docs/sendgrid/glossary/x-message-id.md): \*Analytics\*. An SMTP email header that Twilio SendGrid includes in email messages it sends as event webhook metadata.
* [Twilio SendGrid](/docs/sendgrid.md): Learn to send transactional and marketing emails at scale with the platform that offers a 99% deliverability rate. From quickstarts and onboarding guides to full API reference, the Twilio SendGrid docs have everything you need to send email at scale.
* [Email API Onboarding](/docs/sendgrid/onboarding/email-api.md): Build a scalable email program with the Twilio SendGrid Email API Onboarding Guide, covering email foundations, architecture, integration, and monitoring.
* [Twilio SendGrid Onboarding Guides](/docs/sendgrid/onboarding.md): Find documentation, sample code, and developer tools to build a dependable email program on Twilio SendGrid's cloud-based mail transfer agent.
* [Accessing email account associated with SendGrid](/docs/sendgrid/ui/account-and-settings/accessing-email-account-associated-with-sendgrid.md): Recover access to the email address associated with your Twilio SendGrid account, including options through Unified Identity with Twilio.
* [Account Under Review](/docs/sendgrid/ui/account-and-settings/account-under-review.md): If your account is suspended or is otherwise under review, learn how to bring your account into good standing.
* [Account Details](/docs/sendgrid/ui/account-and-settings/account.md): Manage your Twilio SendGrid Account Details, including personal information, Twilio SendGrid credentials, time zone, and company name, address, and website.
* [API Keys](/docs/sendgrid/ui/account-and-settings/api-keys.md): Create, manage, store, and test Twilio SendGrid API keys to authenticate access to Twilio SendGrid services and set permission scopes for each key.
* [Billing](/docs/sendgrid/ui/account-and-settings/billing.md): Manage Twilio SendGrid billing, including payment cards, invoices, plan changes, subusers, refunds, and how to cancel or delete your account.
* [Configuring Sign in with Apple](/docs/sendgrid/ui/account-and-settings/configuring-sign-in-with-apple.md): Configure your authenticated domain to support Sign in with Apple and successfully deliver email to Apple's Private Email Relay addresses.
* [Add a Custom SSL Configuration](/docs/sendgrid/ui/account-and-settings/custom-ssl-configurations.md): Set up a custom SSL for click and open tracking by establishing link branding on your account. Avoid DNS validation errors.
* [Dedicated IP addresses](/docs/sendgrid/ui/account-and-settings/dedicated-ip-addresses.md): Acquire, allocate, warm up, and assign dedicated IP addresses in Twilio SendGrid to control your sender reputation and improve email deliverability.
* [Verify message integrity with DKIM](/docs/sendgrid/ui/account-and-settings/dkim-records.md): Learn how DomainKeys Identified Mail (DKIM) verifies that the content of an email message doesn't change in transit.
* [Configure domain authentication](/docs/sendgrid/ui/account-and-settings/how-to-set-up-domain-authentication.md): Set up domain and sender authentication to improve deliverability and security of emails.
* [How to set up link branding](/docs/sendgrid/ui/account-and-settings/how-to-set-up-link-branding.md): Set up link branding to improve your deliverability and security of your emails.
* [How to set up reverse DNS](/docs/sendgrid/ui/account-and-settings/how-to-set-up-reverse-dns.md): Set up reverse DNS to improve your deliverability and security of your emails.
* [Inbound Parse](/docs/sendgrid/ui/account-and-settings/inbound-parse.md): Configure the Twilio SendGrid Inbound Parse Webhook to receive incoming emails, then parse their content, attachments, and headers and POST them to your URL.
* [IP Access Management](/docs/sendgrid/ui/account-and-settings/ip-access-management.md): Control which IPs have access to your SendGrid account.
* [IP Pools](/docs/sendgrid/ui/account-and-settings/ip-pools.md): Group your dedicated Twilio SendGrid IP addresses into IP Pools to control deliverability and sender reputation. Create, edit, and delete IP Pools in the console.
* [Troubleshooting account login issues](/docs/sendgrid/ui/account-and-settings/log-in-issues.md): Troubleshoot Twilio SendGrid account login issues, including unconfirmed email addresses, forgotten usernames, password resets, billing terminations, and banned accounts.
* [Mail Settings](/docs/sendgrid/ui/account-and-settings/mail.md): Manage Twilio SendGrid mail settings, including the address allow list, bounce purge, event notification, footer, bounce and spam forwarding, and email templates.
* [Resetting your Username and Password](/docs/sendgrid/ui/account-and-settings/resetting-your-username-and-password.md): Steps for resetting your username and password using the SendGrid UI
* [Twilio SendGrid Single Sign-On with Azure Active Directory](/docs/sendgrid/ui/account-and-settings/sso-azure-ad.md): Follow this guide to configure Twilio SendGrid's Single Sign-On with Microsoft Azure Active Directory using SAML 2.0 for user authentication.
* [SendGrid Single Sign-On](/docs/sendgrid/ui/account-and-settings/sso.md): Twilio SendGrid's Single Sign-On system integrates with platforms like Okta and Azure. Easy setup and administration for API Pro and Premier Plans.
* [Subusers](/docs/sendgrid/ui/account-and-settings/subusers.md): Create and Manage Subusers
* [Teammate Permissions](/docs/sendgrid/ui/account-and-settings/teammate-permissions.md): Reference all the permissions or scopes available for a SendGrid Teammate
* [Teammates](/docs/sendgrid/ui/account-and-settings/teammates.md): Add, manage, and remove Teammates in the Twilio SendGrid UI to share one account across users with role-based permissions, SSO, and API key access.
* [Tracking settings](/docs/sendgrid/ui/account-and-settings/tracking.md): Track clicks, opens, and subscriptions with Twilio SendGrid
* [Troubleshooting Delays and Latency](/docs/sendgrid/ui/account-and-settings/troubleshooting-delays-and-latency.md): Diagnose Twilio SendGrid email delays and latency using Twilio SendGrid libraries, hping, traceroute, the Google header analyzer, and Wireshark packet captures.
* [Troubleshooting Sender Authentication](/docs/sendgrid/ui/account-and-settings/troubleshooting-sender-authentication.md): Troubleshoot Twilio SendGrid sender authentication, including DNS records that won't validate, DMARC failures, underscores, and manual DNS checks.
* [Twilio Login Overview](/docs/sendgrid/ui/account-and-settings/twilio-login-overview.md): Learn how to connect your SendGrid or Segment accounts with your Twilio account from the Twilio Console.
* [Two-factor authentication](/docs/sendgrid/ui/account-and-settings/two-factor-authentication.md): Two-Factor Authentication gives you an extra layer of security to protect your Twilio SendGrid account.
* [Upgrade your plan](/docs/sendgrid/ui/account-and-settings/upgrading-your-plan.md): Upgrade your SendGrid plan to enhance email sending capabilities. Explore flexible options to meet your business needs.
* [Verifying your Account](/docs/sendgrid/ui/account-and-settings/verifying-your-account.md): Verify your Twilio SendGrid account by confirming your email, authenticating your domain, enabling two-factor authentication, and adding a payment method.
* [Bounce and Block Classifications](/docs/sendgrid/ui/analytics-and-reporting/bounce-and-block-classifications.md): Understand Twilio SendGrid's SMTP bounce and block response classification. Use the Email Activity API or Event Webhook for insights on message failures.
* [Click Tracking & HTML Best Practices](/docs/sendgrid/ui/analytics-and-reporting/click-tracking-html-best-practices.md): Format HTML links so Twilio SendGrid click tracking can find and replace them, and learn how to disable click tracking for individual links.
* [Set up secure click tracking](/docs/sendgrid/ui/analytics-and-reporting/click-tracking-ssl.md): Set up and manage SSL-enabled click and open tracking with Twilio SendGrid. Understand sender authentication setup, SSL operation, and data access via UI or API.
* [Deliverability Insights](/docs/sendgrid/ui/analytics-and-reporting/deliverability-insights.md): Explore Twilio SendGrid's Deliverability Insights, a dashboard providing detailed insights into email delivery performance.
* [Email Activity Feed](/docs/sendgrid/ui/analytics-and-reporting/email-activity-feed.md): Learn how to use the Email Activity Feed to view recent email-activity events, troubleshoot delivery issues, and access extended event history.
* [Email Logs](/docs/sendgrid/ui/analytics-and-reporting/email-logs.md): Email Logs is a next-generation solution for accessing and troubleshooting detailed email data with clear, detailed, and near real-time visibility.
* [Marketing Campaigns Statistics](/docs/sendgrid/ui/analytics-and-reporting/marketing-campaigns-stats.md): Explore current features of Twilio SendGrid's Marketing Campaigns and Deliverability Insights for enhanced email delivery performance analysis and click tracking.
* [Spam Reports](/docs/sendgrid/ui/analytics-and-reporting/spam-reports.md): When a recipient marks your email as spam, their mail provider will let SendGrid know. We will help to prevent you from sending email to this recipient again.
* [Statistics Overview](/docs/sendgrid/ui/analytics-and-reporting/stats-overview.md): View and filter all of your SendGrid account email statistics.
* [Twilio SendGrid user interface documentation](/docs/sendgrid/ui.md): SendGrid's user interface documentation provides information on how to navigate the SendGrid web-based interface, also known as the UI, App, and Console.
* [Integrations](/docs/sendgrid/ui/integrations.md): Integrate 3rd party tools with SendGrid Marketing Campaigns.
* [Building your Contact list](/docs/sendgrid/ui/managing-contacts/building-your-contact-list.md): Directions on how to effectively build your Marketing Campaigns Contact list.
* [Manage contacts](/docs/sendgrid/ui/managing-contacts/create-and-manage-contacts.md): Manage Twilio SendGrid Marketing Campaigns contacts through CSV files, signup forms, the console, or the Contacts API. Add, edit, find, and delete contacts.
* [Personalize and segment messages with custom fields](/docs/sendgrid/ui/managing-contacts/custom-fields.md): Custom fields help you segment your lists dynamically based on your user information.
* [Bulk Email Address Validation Overview](/docs/sendgrid/ui/managing-contacts/email-address-validation/bulk-email-address-validation-overview.md): Use the Twilio SendGrid Bulk Email Address Validation API to asynchronously validate up to one million email addresses from a CSV file and clean your lists.
* [Email Address Validation Overview](/docs/sendgrid/ui/managing-contacts/email-address-validation.md): Remove invalid email addresses from your lists, decrease your bounce rate, and improve your sender reputation with the Email Address Validation API.
* [Real Time Email Address Validation Overview](/docs/sendgrid/ui/managing-contacts/email-address-validation/real-time-email-address-validation-overview.md): Validate email addresses in real time with the SendGrid Email Address Validation API to reduce bounces, clean lists, and protect sender reputation.
* [Formatting a CSV](/docs/sendgrid/ui/managing-contacts/formatting-a-csv.md): Directions on how to format a CSV for upload using SendGrid Marketing Campaigns
* [Segmenting your Contacts](/docs/sendgrid/ui/managing-contacts/segmenting-your-contacts.md): Use Marketing Campaigns for dynamic email segmentation based on various conditions. Create, refresh, and manage up to 200 segments per user.
* [A/B Testing Your Single Send](/docs/sendgrid/ui/sending-email/a-b-testing.md): Optimize engagement of your campaigns with A/B testing, by sending different versions of your emails to a small subset of your contacts and measuring the engagement results.
* [Adding Dynamic Content with Handlebars in Marketing Campaigns](/docs/sendgrid/ui/sending-email/adding-dynamic-content-with-handlebars-in-marketing-campaigns.md): The use cases on this page will help you utilize Handlebars helpers to deliver dynamic content targeted to your customers.
* [Sending Attachments with Digioh](/docs/sendgrid/ui/sending-email/attachments-with-digioh.md): Manage file size during email attachment with SendGrid's Marketing Email solution. Learn to use SMTP Relay or Web API v3 effectively.
* [Manage blocked messages](/docs/sendgrid/ui/sending-email/blocks.md): How to find out if an ISP or inbox provider blocks your email.
* [Manage bounced messages](/docs/sendgrid/ui/sending-email/bounces.md): Twilio SendGrid helps prevent you from resending to a recipient whose email server rejects the messages.
* [Use the Code Editor](/docs/sendgrid/ui/sending-email/code-editor.md): Twilio SendGrid Code Editor lets you design your email messages with HTML.
* [Content Delivery Networks](/docs/sendgrid/ui/sending-email/content-delivery-networks.md): Integrate Twilio SendGrid with CDNs such as CloudFront, CloudFlare, Fastly, KeyCDN for efficient content delivery and security management.
* [Using CloudFlare as your Content Delivery Network (CDN)](/docs/sendgrid/ui/sending-email/content-delivery-networks/using-cloudflare-as-your-content-delivery-network-cdn.md): Setup your Content Delivery Network with CloudFlare for effective click tracking. Follow our step-by-step guide and enhance your SSL setup process.
* [Create and Edit Legacy Transactional Templates](/docs/sendgrid/ui/sending-email/create-and-edit-legacy-transactional-templates.md): Create, edit, preview, test, and manage legacy transactional email templates in Twilio SendGrid using the Code Editor or Design Editor.
* [Manage recipients who unsubscribe](/docs/sendgrid/ui/sending-email/create-and-manage-unsubscribe-groups.md): Recipients can choose to unsubscribe from your email messages. How you handle these requests factors heavily into your overall deliverability and sender reputation.
* [Cross-Platform Email Design](/docs/sendgrid/ui/sending-email/cross-platform-html-design.md): HTML and CSS best practices for designing emails that render consistently across email clients, browsers, and devices, covering layout, backgrounds, and images.
* [Improve deliverability](/docs/sendgrid/ui/sending-email/deliverability.md): Best practices to improve Twilio SendGrid email deliverability, including consent, regulations, sender reputation, IP separation, and click tracking.
* [Use the Design Editor](/docs/sendgrid/ui/sending-email/design-editor.md): Twilio SendGrid Design Editor lets you design your email messages with a visual editor.
* [Enforce authentication with a DMARC policy](/docs/sendgrid/ui/sending-email/dmarc.md): Learn how Domain-based Message Authentication, Reporting and Conformance enforces email message authentication results.
* [Choose an email editor](/docs/sendgrid/ui/sending-email/editor.md): Twilio SendGrid Marketing Campaigns' editing gives you complete control over your emails. Use a flexible drag-and-drop Design editor or a robust HTML code editor.
* [Email Testing](/docs/sendgrid/ui/sending-email/email-testing.md): Email Testing for Software Developers: Enhance your emails with features such as spam testing, inbox rendering previews, and link validation.
* [HTML Formatting Issues](/docs/sendgrid/ui/sending-email/formatting-html.md): Follow these HTML formatting guidelines to send email through Twilio SendGrid, preserve content, and fix rendering issues caused by MIME encoding and line length.
* [Get started with Automation](/docs/sendgrid/ui/sending-email/getting-started-with-automation.md): Create an automated email series or drip campaign targeted towards a specific audience with Automation.
* [Global Unsubscribes](/docs/sendgrid/ui/sending-email/global-unsubscribes.md): Recipients can unsubscribe from everything you send, rather than just a single group.
* [Group Unsubscribes](/docs/sendgrid/ui/sending-email/group-unsubscribes.md): Allow recipients to unsubscribe from specific types of email you send, rather than everything you send, and stay out of the spam folder.
* [Send an email with dynamic templates](/docs/sendgrid/ui/sending-email/how-to-send-an-email-with-dynamic-templates.md): Activate and customize dynamic email templates with our comprehensive guide. Master template ID retrieval and implement dynamic data with ease.
* [Prepare your email Marketing Campaign](/docs/sendgrid/ui/sending-email/how-to-send-email-with-marketing-campaigns.md): Prepare a Twilio SendGrid Marketing Campaign by verifying your time zone, adding a sender, setting notifications, adding contacts, and configuring opt-out.
* [Suppressions](/docs/sendgrid/ui/sending-email/index-suppressions.md): Twilio SendGrid suppresses emails that your recipients unsubscribe from or that recipient email servers reject.
* [Invalid email addresses](/docs/sendgrid/ui/sending-email/invalid-emails.md): Twilio SendGrid keeps reports of invalid email addresses for 30 days.
* [List-Unsubscribe](/docs/sendgrid/ui/sending-email/list-unsubscribe.md): Include the List-Unsubscribe header to provide your recipients with an unsubscribe link next to the From address used to deliver mail.
* [Authenticate a single sender](/docs/sendgrid/ui/sending-email/sender-verification.md): Understand the difference between domain authentication and verifying a single sender.
* [Senders](/docs/sendgrid/ui/sending-email/senders.md): Understand email sender identification and how to manage the sender of your email campaign with Twilio SendGrid.
* [Single Sends](/docs/sendgrid/ui/sending-email/single-sends.md): An overview and reference page for customers working with Twilio SendGrid Marketing Campaigns Single Sends.
* [Unsubscribe with Subscription Tracking](/docs/sendgrid/ui/sending-email/subscription-tracking.md): Use SendGrid Subscription Tracking to add and customize unsubscribe links, set a replacement tag, and create an unsubscribe landing page.
* [Substitution and Section Tags](/docs/sendgrid/ui/sending-email/substitution-and-section-tags.md): Personalize SendGrid emails with substitution and section tags. See examples for name, first and last name, greeting, and confirmation tags.
* [Universal Links](/docs/sendgrid/ui/sending-email/universal-links.md): Learn how to set up universal links with click tracking in your emails.
* [Verify sending email servers with SPF](/docs/sendgrid/ui/sending-email/verify-sender-with-spf.md): Identify which servers can send email from your domain with the Sender Policy Framework (SPF). Learn SPF record format, mechanisms, and best practices.
* [The Weblink Substitution Tag](/docs/sendgrid/ui/sending-email/weblink.md): The Weblink tag is replaced with a link that opens the email in a Twilio SendGrid-hosted webpage, making it possible to view an email when an email client fails to open or properly render the message.
* [Create an email design](/docs/sendgrid/ui/sending-email/working-with-marketing-campaigns-email-designs.md): Twilio SendGrid creates messages based on templates called Designs. To create a template for your Single Send messages, start with the Design Library.

## Twilio Video

* [Add Programmable Voice Participants to Video Rooms](/docs/video/adding-programmable-voice-participants-video-rooms.md): Learn how to add Programmable Voice callers as participants in video rooms using the TwiML \<Room> noun within the \<Connect> verb. You can connect inbound calls to your Twilio phone number as well as outgoing calls from your Twilio phone number to video rooms.
* [Twilio Video Quickstart for Android](/docs/video/android-getting-started.md): Learn how to build a video application with Twilio's Video API and the Twilio Android SDK in this Twilio Video Quickstart.
* [Android Video Application Recommendations and Best Practices](/docs/video/android-recommendations-best-practices.md): Recommendations and best practices for building with the Programmable Video Android SDK, including managing audio focus, handling local media, and error handling.
* [Video Android Platform Overview](/docs/video/android.md): Integrate Programmable Video into your Android application using the Video SDK using this sample application as a guide.
* [Composition Hooks](/docs/video/api/composition-hooks.md): Learn about Composition Hooks and their instance and list resources, plus see some examples.
* [Compositions Resource](/docs/video/api/compositions-resource.md): Full API reference for the Composition resource in the Programmable Video API. Create (post), fetch (get), delete, and modify compositions.
* [Encrypted Recordings](/docs/video/api/encrypted-recordings.md): An API reference for the Twilio Recording Settings REST API that lets you configure Twilio to store your recordings encrypted.
* [External S3 Recordings](/docs/video/api/external-s3-recordings.md): The Twilio Recording Settings REST API lets you store Programmable Video recordings in an external AWS S3 bucket at the account or project level.
* [Programmable Video REST API](/docs/video/api.md): Create and complete video rooms, query their status, retrieve recording files, configure webhooks, and more with Twilio's Programmable Video REST API.
* [Participants](/docs/video/api/participants.md): Full API reference for the Participant resource in the Programmable Video API. Sample code shows how to retrieve (get), remove, or update participants.
* [PublishedTrack](/docs/video/api/publishedtrack.md): A full API reference for the Published Track resource of the Programmable Video REST API.
* [Recording Rules](/docs/video/api/recording-rules.md): Use the recording rules REST API to specify which participants' audio and video tracks should be recorded in a video room.
* [Recordings Resource](/docs/video/api/recordings-resource.md): Full API reference for the Recordings resource in the Programmable Video APIs for Rooms and Recordings, complete with sample code.
* [Rooms Resource](/docs/video/api/rooms-resource.md): Share video and audio tracks to a room, and receive video and audio tracks from other participants in a room with Twilio Programmable Video.
* [Status Callbacks](/docs/video/api/status-callbacks.md): Receive events related to your video Rooms via HTTP request with Twilio's Programmable Video Rooms Status Callbacks.
* [Track Subscriptions](/docs/video/api/track-subscriptions.md): Full API reference for all things Track Subscription in the Programmable Video API. Learn how to use these resources, complete with sample code.
* [Real-time Transcriptions for Video](/docs/video/api/transcriptions.md): Enable real-time video transcriptions using this AI-powered tool from Twilio. Convert speech to text, choose your speech model, and customize your app's UI.
* [Building a JS Video App: Recommendations and Best Practices](/docs/video/build-js-video-application-recommendations-and-best-practices.md): Recommendations and best practices for building with the Programmable Video JavaScript SDK, including browser support, local media, and error handling.
* [Configuring Audio, Video Input and Output devices](/docs/video/configuring-audio-video-input-and-output-devices.md): This guide will show you how to configure audio and video input and output devices in your Programmable Video Rooms applications.
* [Detecting the Dominant Speaker](/docs/video/detecting-dominant-speaker.md): Learn how to detect the dominant speaker in a Video Room for Android, iOS, and JavaScript applications.
* [Frequently asked questions](/docs/video/faq.md): Answers to common questions about Twilio Video, including product status, platform support, pricing, and capabilities.
* [Guide to Scaling Applications](/docs/video/guide-to-scaling-applications.md): This guide describes some implementation considerations for your video application to allow it to scale efficiently with Twilio.
* [Video guides](/docs/video/guides.md): Find guides for building, optimizing, and troubleshooting your Twilio Video application.
* [Twilio Video](/docs/video.md): Use Twilio Programmable Video to add video to your web or mobile app. Create applications with video calling functionality, recording, virtual backgrounds, screensharing, diagnostic tooling, and more.
* [Twilio Video Quickstart for iOS](/docs/video/ios-getting-started.md): Learn the basics of building an iOS app using Twilio Video.
* [iOS Video Application Recommendations and Best Practices](/docs/video/ios-recommendations-best-practices.md): Recommendations and best practices for building with the Programmable Video iOS SDK, including handling local media, background the application, and error handling.
* [Video iOS Platform Overview](/docs/video/ios.md): Integrate Programmable Video into your iOS application using the Video SDK, starting with this example iOS application for on mobile phones and tablets.
* [Firewall and Network Configuration](/docs/video/ip-addresses.md): Configure your firewall for Twilio Programmable Video. Includes IP address ranges, ports, protocols, proxy bypass guidance, and troubleshooting for enterprise network environments.
* [Twilio Video Quickstart for JavaScript](/docs/video/javascript-getting-started.md): Quickstart for the JavaScript SDK for Twilio Video: connect to a room, set up local media, work with remote participants, and participate in a room.
* [JavaScript Platform Overview](/docs/video/javascript.md): Learn how to start working with the Programmable Video JavaScript SDK, which lets you add real-time voice and video to your web applications.
* [Legacy Video Room Types](/docs/video/legacy-room-types.md): An overview of legacy Twilio Video Room types: Peer-to-Peer, WebRTC Go, Small Group Rooms, and audio-only Group Rooms
* [Managing codecs](/docs/video/managing-codecs.md): An in-depth guide to managing codecs in Programmable Video to help you understand supported codecs, interoperability, limitations, and known issues.
* [Media Security](/docs/video/media-security.md): Learn about Twilio Programmable Video's security, encryption, and the protocols it uses.
* [Networking Considerations for Video Applications](/docs/video/networking-considerations.md): Learn about network aspects to consider when building a Twilio Video application.
* [Noise Cancellation](/docs/video/noise-cancellation.md): Learn how to add noise cancellation from Krisp.ai to Video Rooms. You can filter out hundreds of types of unwanted background noises from audio tracks with AI-based noise cancellation.
* [Twilio Video technical overview](/docs/video/overview.md): Learn how Twilio Video works and explore the resources you can use as you build, scale, and troubleshoot your applications.
* [Platform SDK Support Policy](/docs/video/platform-sdk-support-policy.md): Find information on how long iOS, Android, and JavaScript SDK versions are officially supported by Twilio.
* [Programmable Video Quotas and Limits](/docs/video/programmable-video-limits.md): Learn about account-based quotas and system-wide limits for Programmable Video rooms and participants.
* [Reconnection States and Events](/docs/video/reconnection-states-and-events.md): An introduction to Programmable Video reconnection states and events, providing guidance and sample code to show how to use them in your applications.
* [Telemedicine Virtual Visits](/docs/video/solutions-blueprint-telemedicine-virtual-visits.md): This guide will walk through a standard implementation of Twilio Programmable Video for telehealth applications using best practices.
* [Specify Audio and Video Constraints in JavaScript](/docs/video/specify-audio-and-video-constraints.md): Sample code and instructions that show how to set constraints on a Programmable Video LocalAudioTrack and LocalVideoTrack for optimization.
* [Video Insights](/docs/video/troubleshooting/insights.md): Use Video Insights to observe your video application, discover trends, and troubleshoot room and participant issues. View an overview dashboard of all your video rooms, dig into detected issues, and see quality metric graphs for all participants.
* [JavaScript Logger](/docs/video/troubleshooting/javascript-logger.md): Learn how to install the JavaScript Logger via npm or Twilio's CDN, then learn how to set the logging level and intercept logs.
* [JavaScript Room Monitor](/docs/video/troubleshooting/javascript-room-monitor.md): The JavaScript Room Monitor displays real-time metrics about a Twilio Video Room. Learn supported browsers, how to add the monitor to your app, and how to use its methods.
* [Pre-call Testing and Diagnostics](/docs/video/troubleshooting/pre-call-testing-and-diagnostics.md): Learn about tools for understanding clients' connections and diagnosing any potential problems before, during, or after a Twilio Video call.
* [Preflight API](/docs/video/troubleshooting/preflight-api.md): How to access and use the Preflight API for testing connectivity to the Twilio Cloud.
* [Video Log Analyzer API](/docs/video/troubleshooting/video-log-analyzer-api.md): Full reference for the Programmable Video Log Analyzer API. Sample code shows how to get a list of rooms and participants and a room's video log data.
* [Developing High Quality Video Applications](/docs/video/tutorials/developing-high-quality-video-applications.md): This guide provides advice for building higher-quality video applications, covering terminology and concepts, requirements, and room quality.
* [Encrypting your Stored Media](/docs/video/tutorials/encrypting-your-stored-media.md): Learn how to encrypt Twilio Video Recordings and Compositions. Use this feature when you need to ensure your recorded media is encrypted end-to-end.
* [Get Started with Twilio Video Part 2: Creating the Frontend](/docs/video/tutorials/get-started-with-twilio-video-node-express-frontend.md): Learn how to create a browser-based video application using JavaScript. This is the second part of a tutorial for building a Twilio Video app using Node/Express for the server and JavaScript for the frontend.
* [Get Started with Twilio Video Part 1: Creating a server with Node or Express](/docs/video/tutorials/get-started-with-twilio-video-node-express-server.md): Learn how to build a browser-based video application using Node and Express. In this part of the two-part tutorial, build out an Access Token server to generate tokens for users who want to join your video chat application.
* [Get Started with Twilio Video Part 2: Creating the Frontend](/docs/video/tutorials/get-started-with-twilio-video-python-flask-frontend.md): The second part of a two-part tutorial for creating a video web application with a Python3/Flask backend (part 1) and a JavaScript frontend (part 2).
* [Get Started with Twilio Video Part 1: Creating a Server with Python/Flask](/docs/video/tutorials/get-started-with-twilio-video-python-flask-server.md): The first part of a two-part tutorial for creating a video web application with a Python3/Flask backend (part 1) and a JavaScript frontend (part 2).
* [Storing into AWS S3](/docs/video/tutorials/storing-aws-s3.md): Learn how to store your Video Recordings and Compositions in your own AWS S3 bucket, rather than in Twilio's cloud.
* [Understanding Video Recordings and Compositions](/docs/video/tutorials/understanding-video-recordings-and-compositions.md): An explainer of the technical concepts behind Programmable Video recordings and compositions.
* [Understanding Video Rooms APIs](/docs/video/tutorials/understanding-video-rooms-apis.md): Go in-depth with all things Video Rooms API for Programmable Video with this guide.
* [Understanding Video Rooms](/docs/video/tutorials/understanding-video-rooms.md): Learn the foundational concepts behind Programmable Video Rooms.
* [User Identity & Access Tokens for Programmable Video](/docs/video/tutorials/user-identity-access-tokens.md): Learn how to control user identity and room permissions in your Programmable Video applications, including access tokens, room access, and time-to-live.
* [Using the Network Bandwidth Profile API](/docs/video/tutorials/using-bandwidth-profile-api.md): Learn how to use the Programmable Video Network Bandwidth Profile API to assign a higher bandwidth to tracks, protect audio quality and manage resources.
* [Video Regions and Global Low Latency](/docs/video/tutorials/video-regions-and-global-low-latency.md): Learn about how geolocation of media and signaling servers impacts call quality. Selecting the right geolocation setting improves the video call experience and reduces call latency. See how to set the signaling and media region for your Twilio Video Rooms depending on your users' locations.
* [Using the DataTrack API - JavaScript](/docs/video/using-datatrack-api.md): Follow sample code and learn how to use the DataTrack API to send messages between participants connected to a room in your Programmable Video application.
* [Using the Network Quality API](/docs/video/using-network-quality-api.md): An introduction to the Network Quality API for Programmable Video with guidance on using Network Quality effectively in your Rooms applications.
* [Components of a Twilio Video app](/docs/video/video-app-components.md): Learn about the main components required to build a multi-participant video application using Twilio Video.
* [Adding Virtual Backgrounds](/docs/video/video-processors.md): Apply transformations and filters, such as blurring and virtual backgrounds, to a Programmable VideoTrack using the Video Processors JavaScript library and the JavaScript SDK
* [Twilio Video Webinar](/docs/video/webinar.md): View this webinar presentation to learn more about Twilio Video.

## Twilio for Salesforce

* [Twilio for Salesforce](/docs/salesforce.md): Learn what you can do with Twilio's managed package for Salesforce. We include ProcessBuilder, Apex, running SMS campaigns, and sending 1:1 messages.

## Unified Profiles (Public Beta)

* [Confirm or update your customer identifier settings (Public Beta)](/docs/unified-profiles/identifiers.md): Unified Profiles uses customer identifiers to search for customer profiles. You can configure these identifiers.
* [Unified Profiles (Public Beta)](/docs/unified-profiles.md): Provide your teams with information about each customer to enhance their understanding of customer intent and enable them to personalize every conversation.
* [Known issues and limitations in Unified Profiles (Public Beta)](/docs/unified-profiles/limitations.md): Known issues and limitations in Unified Profiles.
* [Connect your Segment space (Public Beta)](/docs/unified-profiles/segment-space.md): Learn how to connect your Segment space to work with Unified Profiles.
* [Set up and configure Unified Profiles (Public Beta)](/docs/unified-profiles/setup.md): Learn how to set up and configure Unified Profiles.
* [Choose the traits to use (Public Beta)](/docs/unified-profiles/traits.md): Show customer traits in Unified Profiles to make important customer information available to your agents.

## Verify

* [Access Token Resource](/docs/verify/api/access-token.md): Full API reference for the Access Token resource in the Twilio Verify API. Sample code shows how to create and fetch Access Tokens.
* [Verification Attempts](/docs/verify/api/attempts.md): Full API reference for the Verification Attempts resource in the Twilio Verify API. Sample code shows how to fetch and list Verification Attempts.
* [Challenge Resource](/docs/verify/api/challenge.md): Full API reference for the Challenge resource in the Twilio Verify API for TOTP and Push. Sample code shows how to create, fetch, read, and update a Challenge.
* [Customization Options](/docs/verify/api/customization-options.md): Sample code that shows how to customize verification codes with Verify and information on message templates and localizations for communications.
* [Verify v2 Error Codes](/docs/verify/api/error-codes.md): Explore Verify v2 error codes and find solutions for Twilio Verify issues with our comprehensive guide, covering common errors, causes, and fixes.
* [Factor Resource](/docs/verify/api/factor.md): Full API reference for the Factor resource in the Verify API for TOTP and Push. Sample code shows how to create, fetch, read, update, and delete a Factor.
* [Verify API](/docs/verify/api.md): Simplify user verification with Verify API. Send OTPs via SMS, call, WhatsApp, and more for enhanced security.
* [Protect Your Verify Application with Service Rate Limits](/docs/verify/api/programmable-rate-limits.md): Learn how to protect your Verify application with Service Rate Limits, which let you define verification rate limits.
* [Rate Limits and Timeouts](/docs/verify/api/rate-limits-and-timeouts.md): Learn about rate limits for requesting the status of a verification and the duration of token validity when building with Verify.
* [Safe List](/docs/verify/api/safe-list.md): Full API reference for the Safe List resource in the Twilio Verify API. Sample code shows how to add, check, and remove a phone number from the Safe List.
* [Service Rate Limit Buckets](/docs/verify/api/service-rate-limit-buckets.md): Full API reference for the Service Rate Limit Bucket resource in the Twilio Verify API. Sample code shows how to create, fetch, list all, update, and delete a Bucket.
* [Service Rate Limits](/docs/verify/api/service-rate-limits.md): Full API reference for the Service Rate Limits resource for the Twilio Verify API. Sample code shows how to create, fetch, list, update, and delete.
* [Services](/docs/verify/api/service.md): Full API reference for the Services resource in the Verify API. Sample code shows how to create, fetch, list, update, and delete Services.
* [Templates](/docs/verify/api/templates.md): Templates are predefined and approved messages that allow you to customize your SMS or Voice Verifications.
* [Verification Attempts Summary](/docs/verify/api/verification-attempts-summary.md): Full API reference for the Verification Attempts Summary resource in the Twilio Verify API. Sample code shows how to get and fetch Verification Attempt Summaries.
* [Verification Check](/docs/verify/api/verification-check.md): Full API reference for the Verification Check resource in the Verify API. Sample code shows how to check verifications with a phone number, email, or SID.
* [Verifications](/docs/verify/api/verification.md): Full API reference for the Verifications resource in the Verify API. Sample code shows how to create (start), fetch (get), and update verifications.
* [Verify Push Webhooks](/docs/verify/api/webhooks.md): API reference for Verify Push webhooks and how they can be used to notify your application's backend in real-time when verification statuses change.
* [App Verification with Twilio SMS](/docs/verify/app-verification.md): Learn how to verify Android phone numbers automatically with Twilio Verify and the Google SMS Retriever API, without requiring users to type in an OTP code.
* [Verification Channels](/docs/verify/authentication-channels.md): Choosing the right authentication channels for your app can help increase 2FA adoption and keep your customers secure. Twilio's Verify API supports several channels including SMS, Voice, Email, Passkeys, and TOTP.
* [Verify vs. Authy](/docs/verify/authy-vs-verify.md): The Verify API is a consolidated version of earlier versions of our phone verification and 2FA APIs.
* [Verify Automatic SMS Fallback Overview](/docs/verify/automatic-channel-selection.md): Learn about how to use Twilio Verify API's automatic SMS Fallback feature in this overview.
* [Consent and Opt-in Policy](/docs/verify/consent-opt-in.md): Learn the consent and opt-in compliance rules for sending OTP and 2FA SMS or RCS messages with Twilio Verify, including required US and Canada disclosures.
* [Default Languages for Phone Number Country Codes](/docs/verify/default-phone-verification-languages.md): Learn about how Twilio's Verify API automatically resolves a verification's language based on phone number country code and see the supported mappings.
* [Verification and two-factor authentication best practices](/docs/verify/developer-best-practices.md): Developer best practices for phone and user verification with SMS, voice, email, WhatsApp, TOTP and push channels. Reduce fraud with these tips and tricks.
* [Send Email Verifications with Verify and Twilio SendGrid](/docs/verify/email.md): Set up your Twilio account to send verification emails with Verify and Twilio SendGrid with step-by-step instructions, complete with sample code.
* [Verify Channel Selection](/docs/verify/fallback-scenarios.md): Discover how to enhance OTP verification success with fallback scenarios and optimal channel selection, including SMS, WhatsApp, and RCS.
* [Verify](/docs/verify.md): Verification API with support for multiple channels. Verify user identity and reduce fraud with built-in support for global delivery and translations.
* [Message Status Stream](/docs/verify/message-status.md): Subscribe to specific message status events to identify and respond to issues impacting message delivery by carriers. The message status stream is equivalent to the outbound message event's stream provided by Twilio Programmable Messaging.
* [Preventing Fraud in Verify](/docs/verify/preventing-toll-fraud.md): SMS pumping and voice toll fraud attacks cause inflated traffic to your app and higher costs. Learn how fraudsters can take advantage of your application and how to stop them.
* [Verify Fraud Guard](/docs/verify/preventing-toll-fraud/sms-fraud-guard.md): Learn how to prevent SMS pumping fraud with Twilio's Verify SMS Fraud Guard overview.
* [Verify Geo Permissions](/docs/verify/preventing-toll-fraud/verify-geo-permissions.md): Learn how to configure Geo Permissions for Twilio's Verify API in order to disable verification sends to specific countries to help prevent fraud.
* [Verify Push & Silent Device Approval Overview](/docs/verify/push.md): Learn how to add a push authentication factor to verify users in your app with Twilio's Verify Push overview.
* [Verify Push Client Library Technical Overview](/docs/verify/push/technical-overview.md): Learn how Twilio's Verify Push SDK works in this technical overview with sequence diagrams, sample app demos, data models, and resource definitions.
* [Verify C# ASP.NET Core Quickstart](/docs/verify/quickstarts/csharp-asp-net-core-mvc.md): Learn how to verify phone numbers using the Verify REST API, the Twilio C# SDK, and C# ASP.NET Core with this quickstart.
* [Verify Quickstarts](/docs/verify/quickstarts.md): Find links to all Twilio Verify quickstarts and learn how to verify user identity with Verify and your supported programming language of choice.
* [Verify Node.js Express Quickstart](/docs/verify/quickstarts/node-express.md): Learn how to send an SMS verification with the Verify REST API, the Twilio Node.js SDK, and Express.js in this quickstart.
* [Verify PHP Laravel Quickstart](/docs/verify/quickstarts/php-laravel.md): Learn how to send an SMS verification with the Verify API, Twilio's PHP helper library, and the Laravel web framework in this quickstart.
* [Verify Python Flask Quickstart](/docs/verify/quickstarts/python-flask.md): This quickstart shows you how to send your first SMS verification with the Verify REST API, the Twilio Python SDK, and the Flask micro-framework
* [Verify TOTP Quickstart](/docs/verify/quickstarts/totp.md): Learn how to send Time-based One-Time Passwords (TOTP) verifications so you can authenticate users with apps like Authy or Google Authenticator.
* [Verify RCS Upgrade](/docs/verify/rcs.md): Learn how Twilio Verify automatically upgrades one-time passcode (OTP) delivery from SMS to the RCS channel for lower cost and better performance.
* [Singapore Sender ID Handling](/docs/verify/singapore.md): How Verify handles Sender IDs when sending to Singapore
* [Verify SMS overview](/docs/verify/sms.md): Learn how to implement SMS-based phone verification and two-factor authentication with Twilio Verify.
* [Verify Silent Network Auth Overview](/docs/verify/sna.md): Learn about Twilio Verify's Silent Network Auth verifications in this overview.
* [Verify Silent Network Auth Technical Overview](/docs/verify/sna/tech-overview.md): Technical overview and sequence diagram for the Twilio Verify Silent Network Auth feature
* [Verify supported languages](/docs/verify/supported-languages.md): Learn about the different languages and locales Twilio Verify supports for sending Verifications in this guide.
* [Verify TOTP Overview](/docs/verify/totp.md): Learn more about sending time-based one-time passcode (TOTP) user verifications via Twilio's Verify API TOTP Overview.
* [Verify TOTP Technical Overview](/docs/verify/totp/technical-overview.md): Learn about the technical specifics of Twilio's Verify API TOTP verification feature in this overview.
* [Getting Started with Verification Templates](/docs/verify/verification-templates.md): Learn more about the available templates Twilio Verify can use to send Verifications and how to configure them.
* [Verification Stream](/docs/verify/verification.md): Subscribe to Twilio Verify verification status events through Event Streams to track the lifecycle of a verification, from pending to approved, expired, or canceled.
* [Verify Countries and Regions Deliverability](/docs/verify/verify-countries-and-regions-deliverability.md): Learn about what countries and regions have deliverability support with Twilio's Verify API.
* [Verify Events](/docs/verify/verify-events.md): Verify Events provides instant information on your Verify Service's activity, allowing you to tap into events via webhook or other streaming technology.
* [Verify SNA Live Test Number](/docs/verify/verify-sna-live-test-number.md): Learn how to use Twilio's Verify Silent Network Auth Live Test Number for testing SNA with your own personal number.
* [Verify Transactions for PSD2](/docs/verify/verifying-transactions-psd2.md): Learn how to use Twilio's Verify API to verify transactions in a way that is compliant with Payment Service Directive 2 (PSD2).
* [Viewing Logs with Twilio Console](/docs/verify/viewing-logs-with-twilio-console.md): Learn how to view the logs of your Verify Service using the Twilio Console interface in this guide.
* [Bring Your Own WhatsApp Sender](/docs/verify/whatsapp/byo.md): Bring your own WhatsApp Sender to send Twilio Verify WhatsApp OTP messages from your own brand, comply with Meta policy, and use branded Authentication Templates.
* [Verify WhatsApp Overview](/docs/verify/whatsapp.md): Learn more about sending one-time passcode (OTP) user verifications via WhatsApp with Twilio's Verify WhatsApp Overview.

## WhatsApp Business Platform with Twilio

* [List of Corresponding Twilio and WhatsApp Error Codes](/docs/whatsapp/api/error-code-mapping.md): A table of the corresponding Twilio and WhatsApp error codes. Debug efficiently with a mapping of common Twilio error codes to their WhatsApp counterpart.
* [Twilio Event Streams for WhatsApp](/docs/whatsapp/api/events.md): Learn about WhatsApp event types, schemas, and how to subscribe to real-time notifications for updates to your WhatsApp integration through Twilio.
* [Overview of the WhatsApp Business Platform with Twilio](/docs/whatsapp/api.md): Complete Twilio API for WhatsApp overview showing API calls, parameters, message formatting, and common examples and responses.
* [Senders API - WhatsApp](/docs/whatsapp/api/senders.md): Register and manage your Twilio WhatsApp Senders using the Senders API
* [The WhatsApp Business Platform with Twilio: Best Practices and FAQs](/docs/whatsapp/best-practices-and-faqs.md): Best practices and FAQs on WhatsApp and the Twilio API for WhatsApp. Learn how to get started with a WhatsApp integration including samples.
* [Using Buttons In WhatsApp](/docs/whatsapp/buttons.md): Instructions and sample code that show how to add quick-reply or call-to-action buttons to your WhatsApp messages to increase engagement with customers.
* [Editing your WhatsApp Business Profile](/docs/whatsapp/editing-your-whatsapp-business-profile.md): Learn how to edit your WhatsApp Business Profile to display accurate business information to your end-users.
* [Guidance on WhatsApp Media Messages](/docs/whatsapp/guidance-whatsapp-media-messages.md): Guidance for content-type and media file size limits. Send media messages in WhatsApp using the Twilio API for WhatsApp.
* [WhatsApp Business Platform with Twilio](/docs/whatsapp.md): Integrate WhatsApp messaging into your business with Twilio APIs.
* [Key Concepts and Terms for the WhatsApp Business Platform with Twilio](/docs/whatsapp/key-concepts.md): Learn the key concepts and terms for the WhatsApp Business Platform with Twilio, including customer service windows, message templates, WABAs, and usernames.
* [Rich Messaging Features in the Twilio API for WhatsApp](/docs/whatsapp/message-features.md): Twilio supports the latest WhatsApp-specific features to make it easier for your customers to engage with you. Reach your customers through WhatsApp using the Twilio API for WhatsApp.
* [Quickstart: Send and receive WhatsApp messages](/docs/whatsapp/quickstart.md): Quickstart guide and sample code for developers to try the WhatsApp Business Platform with Twilio. Start connecting with WhatsApp users.
* [Test WhatsApp messaging with the Sandbox](/docs/whatsapp/sandbox.md): With the Twilio Sandbox for WhatsApp, you can start prototyping with Twilio API functionality and sending WhatsApp messages right away: outbound and inbound messages, status callbacks, and more!
* [Register WhatsApp senders using Self Sign-up](/docs/whatsapp/self-sign-up.md): Learn how to register a WhatsApp sender using the Self Sign-up in the Twilio Console.
* [Twilio API for WhatsApp Tutorials](/docs/whatsapp/tutorial.md): Tutorials and sample code for sending, receiving images, PDFs, and audio, reminders, notifications, messages with the Twilio API for WhatsApp.
* [Message template approvals and statuses](/docs/whatsapp/tutorial/message-template-approvals-statuses.md): Understand the approval process, common rejection reasons, and best practices for WhatsApp message templates.
* [Send and Receive Media Messages with the Twilio API for WhatsApp](/docs/whatsapp/tutorial/send-and-receive-media-messages-twilio-api-whatsapp.md): Find links to step-by-step tutorials to learn how to use the Programmable Messaging API to send and receive WhatsApp media messages from your applications.
* [Send and Receive Media Messages with WhatsApp in C#/ASP.NET](/docs/whatsapp/tutorial/send-and-receive-media-messages-whatsapp-csharp-aspnet.md): How to send media messages with the Twilio API for WhatsApp. Add media attachments like images, audio files, and PDF documents to WhatsApp messages with Twilio.
* [Send and Receive Media Messages with WhatsApp in Node.js](/docs/whatsapp/tutorial/send-and-receive-media-messages-whatsapp-nodejs.md): How to send media messages with the Twilio API for WhatsApp. Add media attachments like images, audio files, and PDF documents to WhatsApp messages with Twilio.
* [Send and Receive Media Messages with WhatsApp in PHP](/docs/whatsapp/tutorial/send-and-receive-media-messages-whatsapp-php.md): Learn how to send media messages with the Twilio API for WhatsApp. Add media attachments like images, audio files, and PDF documents to WhatsApp messages with Twilio.
* [Send and Receive Media Messages with WhatsApp in Python](/docs/whatsapp/tutorial/send-and-receive-media-messages-whatsapp-python.md): How to send media messages with the Twilio API for WhatsApp. Add media attachments like images, audio files, and PDF documents to WhatsApp messages with Twilio.
* [Send WhatsApp notification messages with templates](/docs/whatsapp/tutorial/send-whatsapp-notification-messages-templates.md): Create and send WhatsApp notification message templates using Twilio API. Learn template categories, approval process, and implementation examples.
* [Using WhatsApp Business Accounts with Twilio](/docs/whatsapp/tutorial/whatsapp-business-account.md): Learn about WhatsApp Official Business Accounts ("green tick") and how to request one for your Twilio WhatsApp sender

## api

* [Error and Warning Dictionary](/docs/api/errors.md): Explore the full list of all possible Twilio REST API error codes.

## comms

* [Sender Pools](/docs/comms/sender-pools.md): Learn how to manage sender resources with Sender Pools in Twilio Communications API.