Call Resource

A Call is an object that represents a connection between a telephone and Twilio.

Using this resource, you can initiate a call, fetch information about a completed call, fetch a list of calls made to and from your account, redirect or end a call that is in progress, and delete records of past calls from your account.

An inbound call occurs when a person calls one of your Twilio phone numbers, client connections, or SIP-enabled endpoints. An outbound call happens when you initiate a call from a Twilio phone number to an outside phone number, client, or SIP domain.

You can initiate an outbound call by POSTing to the Call resource, creating a new call.

You can also initiate a call from an active call (e.g., forwarding to another number or dialing into a conference) by including TwiML’s <Dial> verb in your TwiML application. However, the only way to initiate a call directly from Twilio is with an API request.

Are you looking for step-by-step instructions for making your first call with Twilio using the helper libraries? Check out one of our quickstarts in your programming language of choice: C#/.NET, Java, Node.js, PHP, Python, or Ruby.

Call properties

Resource Properties in REST API format
`sid`	sid<CA> Not PII The unique string that we created to identify this Call resource.
`date_created`	date_time<rfc2822> Not PII The date and time in GMT that this resource was created specified in RFC 2822 format.
`date_updated`	date_time<rfc2822> Not PII The date and time in GMT that this resource was last updated, specified in RFC 2822 format.
`parent_call_sid`	sid<CA> Not PII The SID that identifies the call that created this leg.
`account_sid`	sid<AC> Not PII The SID of the Account that created this Call resource.
`to`	string PII MTL: 120 DAYS The phone number, SIP address, Client identifier or SIM SID that received this call. Phone numbers are in E.164 format (e.g., +16175551212). SIP addresses are formatted as `name@company.com`. Client identifiers are formatted `client:name`. SIM SIDs are formatted as `sim:sid`.
`to_formatted`	string PII MTL: 120 DAYS The phone number, SIP address or Client identifier that received this call. Formatted for display. Non-North American phone numbers are in E.164 format (e.g., +442071838750).
`from`	string PII MTL: 120 DAYS The phone number, SIP address, Client identifier or SIM SID that made this call. Phone numbers are in E.164 format (e.g., +16175551212). SIP addresses are formatted as `name@company.com`. Client identifiers are formatted `client:name`. SIM SIDs are formatted as `sim:sid`.
`from_formatted`	string PII MTL: 120 DAYS The calling phone number, SIP address, or Client identifier formatted for display. Non-North American phone numbers are in E.164 format (e.g., +442071838750).
`phone_number_sid`	sid<PN> Not PII If the call was inbound, this is the SID of the IncomingPhoneNumber resource that received the call. If the call was outbound, it is the SID of the OutgoingCallerId resource from which the call was placed.
`status`	enum:status Not PII The status of this call. Can be: `queued`, `ringing`, `in-progress`, `canceled`, `completed`, `failed`, `busy` or `no-answer`. See Call Status Values below for more information.
`start_time`	date_time<rfc2822> Not PII The start time of the call, given as GMT in RFC 2822 format. Empty if the call has not yet been dialed.
`end_time`	date_time<rfc2822> Not PII The time the call ended, given as GMT in RFC 2822 format. Empty if the call did not complete successfully.
`duration`	string Not PII The length of the call in seconds. This value is empty for busy, failed, unanswered, or ongoing calls.
`price`	string? Not PII The charge for this call, in the currency associated with the account. Populated after the call is completed. May not be immediately available.
`price_unit`	currency Not PII The currency in which `Price` is measured, in ISO 4127 format (e.g., `USD`, `EUR`, `JPY`). Always capitalized for calls.
`direction`	string? Not PII A string describing the direction of the call. Can be: `inbound` for inbound calls, `outbound-api` for calls initiated via the REST API or `outbound-dial` for calls initiated by a `<Dial>` verb. Using Elastic SIP Trunking, the values can be `trunking-terminating` for outgoing calls from your communications infrastructure to the PSTN or `trunking-originating` for incoming calls to your communications infrastructure from the PSTN.
`answered_by`	string Not PII Either `human` or `machine` if this call was initiated with answering machine detection. Empty otherwise.
`api_version`	string Not PII The API version used to create the call.
`forwarded_from`	string PII MTL: 120 DAYS The forwarding phone number if this call was an incoming call forwarded from another number (depends on carrier supporting forwarding). Otherwise, empty.
`group_sid`	sid<GP> Not PII The Group SID associated with this call. If no Group is associated with the call, the field is empty.
`caller_name`	string PII MTL: 120 DAYS The caller's name if this call was an incoming call to a phone number with caller ID Lookup enabled. Otherwise, empty.
`queue_time`	string Not PII The wait time in milliseconds before the call is placed.
`trunk_sid`	sid<TK> Not PII The unique identifier of the trunk resource that was used for this call. The field is empty if the call was not made using a SIP trunk or if the call is not terminated.
`uri`	uri Not PII The URI of this resource, relative to `https://api.twilio.com`.
`subresource_uris`	uri_map Not PII A list of subresources available to this call, identified by their URIs relative to `https://api.twilio.com`.

Call status values

The following are the possible values for the Status parameter:

Status	Description
`queued`	The call is ready and waiting in line before dialing.
`ringing`	The call is currently ringing.
`in-progress`	The call was answered and is currently in progress.
`canceled`	The call was hung up while it was queued or ringing.
`completed`	The call was answered and has ended normally.
`busy`	The caller received a busy signal.
`no-answer`	There was no answer or the call was rejected.
`failed`	The call could not be completed as dialed, most likely because the phone number was non-existent.

Create a Call resource

post

https://api.twilio.com/2010-04-01/Accounts/{AccountSid}/Calls.json

Calls can be made via the REST API to phone numbers, SIP addresses, or client identifiers. To place a new outbound call, make an HTTP POST request to your account’s Call resource.

Parameters

Parameters in REST API format
`account_sid` Path	post sid<AC> Not PII The SID of the Account that will create the resource.
`to` Required	post endpoint PII MTL: 120 DAYS The phone number, SIP address, or client identifier to call.
`from` Required	post endpoint PII MTL: 120 DAYS The phone number or client identifier to use as the caller id. If using a phone number, it must be a Twilio number or a Verified outgoing caller id for your account. If the `to` parameter is a phone number, `From` must also be a phone number.
`method` Optional	post http_method Not PII The HTTP method we should use when calling the `url` parameter's value. Can be: `GET` or `POST` and the default is `POST`. If an `application_sid` parameter is present, this parameter is ignored.
`fallback_url` Optional	post url Not PII The URL that we call using the `fallback_method` if an error occurs when requesting or executing the TwiML at `url`. If an `application_sid` parameter is present, this parameter is ignored.
`fallback_method` Optional	post http_method Not PII The HTTP method that we should use to request the `fallback_url`. Can be: `GET` or `POST` and the default is `POST`. If an `application_sid` parameter is present, this parameter is ignored.
`status_callback` Optional	post url Not PII The URL we should call using the `status_callback_method` to send status information to your application. If no `status_callback_event` is specified, we will send the `completed` status. If an `application_sid` parameter is present, this parameter is ignored. URLs must contain a valid hostname (underscores are not permitted).
`status_callback_event` Optional	post string[] Not PII The call progress events that we will send to the `status_callback` URL. Can be: `initiated`, `ringing`, `answered`, and `completed`. If no event is specified, we send the `completed` status. If you want to receive multiple events, specify each one in a separate `status_callback_event` parameter. See the code sample for monitoring call progress. If an `application_sid` is present, this parameter is ignored.
`status_callback_method` Optional	post http_method Not PII The HTTP method we should use when calling the `status_callback` URL. Can be: `GET` or `POST` and the default is `POST`. If an `application_sid` parameter is present, this parameter is ignored.
`send_digits` Optional	post string Not PII A string of keys to dial after connecting to the number, maximum of 32 digits. Valid digits in the string include: any digit (`0`-`9`), '`#`', '`*`' and '`w`', to insert a half second pause. For example, if you connected to a company phone number and wanted to pause for one second, and then dial extension 1234 followed by the pound key, the value of this parameter would be `ww1234#`. Remember to URL-encode this string, since the '`#`' character has special meaning in a URL. If both `SendDigits` and `MachineDetection` parameters are provided, then `MachineDetection` will be ignored.
`timeout` Optional	post integer Not PII The integer number of seconds that we should allow the phone to ring before assuming there is no answer. The default is `60` seconds and the maximum is `600` seconds. For some call flows, we will add a 5-second buffer to the timeout value you provide. For this reason, a timeout value of 10 seconds could result in an actual timeout closer to 15 seconds. You can set this to a short time, such as `15` seconds, to hang up before reaching an answering machine or voicemail.
`record` Optional	post boolean Not PII Whether to record the call. Can be `true` to record the phone call, or `false` to not. The default is `false`. The `recording_url` is sent to the `status_callback` URL.
`recording_channels` Optional	post string Not PII The number of channels in the final recording. Can be: `mono` or `dual`. The default is `mono`. `mono` records both legs of the call in a single channel of the recording file. `dual` records each leg to a separate channel of the recording file. The first channel of a dual-channel recording contains the parent call and the second channel contains the child call.
`recording_status_callback` Optional	post string Not PII The URL that we call when the recording is available to be accessed.
`recording_status_callback_method` Optional	post http_method Not PII The HTTP method we should use when calling the `recording_status_callback` URL. Can be: `GET` or `POST` and the default is `POST`.
`sip_auth_username` Optional	post string Not PII The username used to authenticate the caller making a SIP call.
`sip_auth_password` Optional	post string Not PII The password required to authenticate the user account specified in `sip_auth_username`.
`machine_detection` Optional	post string Not PII Whether to detect if a human, answering machine, or fax has picked up the call. Can be: `Enable` or `DetectMessageEnd`. Use `Enable` if you would like us to return `AnsweredBy` as soon as the called party is identified. Use `DetectMessageEnd`, if you would like to leave a message on an answering machine. If `send_digits` is provided, this parameter is ignored. For more information, see Answering Machine Detection.
`machine_detection_timeout` Optional	post integer Not PII The number of seconds that we should attempt to detect an answering machine before timing out and sending a voice request with `AnsweredBy` of `unknown`. The default timeout is 30 seconds.
`recording_status_callback_event` Optional	post string[] Not PII The recording status events that will trigger calls to the URL specified in `recording_status_callback`. Can be: `in-progress`, `completed` and `absent`. Defaults to `completed`. Separate multiple values with a space.
`trim` Optional	post string Not PII Whether to trim any leading and trailing silence from the recording. Can be: `trim-silence` or `do-not-trim` and the default is `trim-silence`.
`caller_id` Optional	post string Not PII The phone number, SIP address, or Client identifier that made this call. Phone numbers are in E.164 format (e.g., +16175551212). SIP addresses are formatted as `name@company.com`.
`machine_detection_speech_threshold` Optional	post integer Not PII The number of milliseconds that is used as the measuring stick for the length of the speech activity, where durations lower than this value will be interpreted as a human and longer than this value as a machine. Possible Values: 1000-6000. Default: 2400.
`machine_detection_speech_end_threshold` Optional	post integer Not PII The number of milliseconds of silence after speech activity at which point the speech activity is considered complete. Possible Values: 500-5000. Default: 1200.
`machine_detection_silence_timeout` Optional	post integer Not PII The number of milliseconds of initial silence after which an `unknown` AnsweredBy result will be returned. Possible Values: 2000-10000. Default: 5000.
`async_amd` Optional	post string Not PII Select whether to perform answering machine detection in the background. Default, blocks the execution of the call until Answering Machine Detection is completed. Can be: `true` or `false`.
`async_amd_status_callback` Optional	post url Not PII The URL that we should call using the `async_amd_status_callback_method` to notify customer application whether the call was answered by human, machine or fax.
`async_amd_status_callback_method` Optional	post http_method Not PII The HTTP method we should use when calling the `async_amd_status_callback` URL. Can be: `GET` or `POST` and the default is `POST`.
`byoc` Optional	post sid<BY> Not PII The SID of a BYOC (Bring Your Own Carrier) trunk to route this call with. Note that `byoc` is only meaningful when `to` is a phone number; it will otherwise be ignored. (Beta)
`call_reason` Optional	post string PII MTL: 120 DAYS The Reason for the outgoing call. Use it to specify the purpose of the call that is presented on the called party's phone. (Branded Calls Beta)
`call_token` Optional	post string Not PII A token string needed to invoke a forwarded call. A call_token is generated when an incoming call is received on a Twilio number. Pass an incoming call's call_token value to a forwarded call via the call_token parameter when creating a new call. A forwarded call should bear the same CallerID of the original incoming call.
`recording_track` Optional	post string Not PII The audio track to record for the call. Can be: `inbound`, `outbound` or `both`. The default is `both`. `inbound` records the audio that is received by Twilio. `outbound` records the audio that is generated from Twilio. `both` records the audio that is received and generated by Twilio.
`time_limit` Optional	post integer Not PII The maximum duration of the call in seconds. Constraints depend on account and configuration.
`url` Required if twiml, application_sid is not passed	post url Not PII The absolute URL that returns the TwiML instructions for the call. We will call this URL using the `method` when the call connects. For more information, see the Url Parameter section in Making Calls.
`twiml` Required if url, application_sid is not passed	post twiml Not PII TwiML instructions for the call Twilio will use without fetching Twiml from url parameter. If both `twiml` and `url` are provided then `twiml` parameter will be ignored. Max 4000 characters.
`application_sid` Required if url, twiml is not passed	post sid<AP> Not PII The SID of the Application resource that will handle the call, if the call will be handled by an application.

Parameter	Description
CallSid	A unique identifier for this call, generated by Twilio.
AccountSid	Your Twilio account ID. It is 34 characters long, and always starts with the letters `AC`.
From	The phone number or client identifier of the party that initiated the call. Phone numbers use E.164 formatting, meaning they start with a + and country code, e.g. `+16175551212`. Client identifiers begin with the `client:` URI scheme; for example, on a call from a client named ‘charlie’ the `From` parameter will be `client:charlie`.
To	The phone number or client identifier of the called party. Phone numbers use E.164 formatting, meaning they start with a `+` and country code, e.g. `+16175551212`. Client identifiers begin with the `client:` URI scheme; for example, for a call to a client named ‘joey’, the `To` parameter will be `client:joey`.
CallStatus	A descriptive status for the call. The value is one of the following: `queued`, `initiated`, `ringing`, `in-progress`, `completed`, `busy`, `failed` or `no-answer`.
ApiVersion	The version of the Twilio API used to handle this call. For incoming calls, this is determined by the API version set on the dialed number. For outgoing calls, this is the version used in the REST API request of the outgoing call.
Direction	A string describing the direction of the call: `inbound` for inbound calls `outbound-api` for calls initiated via the REST API `outbound-dial` for calls initiated by a `<Dial>` verb.
ForwardedFrom	This parameter may be set when Twilio receives a forwarded call. The carrier who forwards the call determines the contents of the parameter. Not all carriers support passing this information. Some carriers provide this information when making a direct call to a Twilio number.
CallerName	This parameter is set when the IncomingPhoneNumber that received the call has set its `VoiceCallerIdLookup` value to `true` ($0.01 per lookup).
ParentCallSid	A unique identifier for the call that created this leg. If this is the first leg of a call, this parameter is not included.

Event	Description
`initiated`	Twilio removes your call from the queue and starts dialing.
`ringing`	The call starts ringing.
`answered`	The call is answered. If this event is specified, Twilio will send an `in-progress` status.
`completed`	The call is completed, regardless of the termination status (which can be `busy`, `cancelled`, `completed`, `failed`, or `no-answer`). If no `StatusCallbackEvent` is specified, completed is fired by default.

Parameter	Description
`CallStatus`	A descriptive status for the call. The value is one of `queued`, `initiated`, `ringing`, `in-progress`, `busy`, `failed`, or `no-answer`. For more details, see the CallStatus values in our TwiML introduction.
`Duration`	The duration in minutes of the just-completed call; calls are billed by the minute. Only present in the `completed` event.
`CallDuration`	The duration in seconds of the just-completed call. Only present in the `completed` event.
`SipResponseCode`	The SIP code that resulted in a failed call. For instance, a number that was unreachable will return 404, and if the Timeout value was reached before the call connected this code will be 487. Only present in the `completed` event if the CallStatus is `failed` or `no-answer`.
`RecordingUrl`	The URL of the phone call’s recorded audio. This parameter is included only if `Record=true` is set on the REST API request and does not include recordings initiated in other ways. `RecordingUrl` is only present in the `completed` event. The recording file may not yet be accessible when the Status Callback is sent. *Note:* Use RecordingStatusCallback for reliable notification on when the recording is available for access.
`RecordingSid`	The unique ID of the Recording from this call. `RecordingSid` is only present with the `completed` event.
`RecordingDuration`	The duration of the recorded audio (in seconds). `RecordingDuration` is only present in the `completed` event. To get a final accurate recording duration after any trimming of silence, use `RecordingStatusCallback`.
`Timestamp`	The timestamp when the event fired, given as UTC in RFC 2822 format.
`CallbackSource`	A string that describes the source of the webhook. This is provided to help disambiguate why the webhook was made. On Status Callbacks, this value is always `call-progress-events`.
`SequenceNumber`	The order in which the events were fired, starting from `0`. Although events are fired in order, they are made as separate HTTP requests, and there is no guarantee they will arrive in the same order.

Parameter	Description
`AccountSid`	The unique identifier of the Account responsible for this recording.
`CallSid`	A unique identifier for the call associated with the recording. CallSid will always refer to the parent leg of a two-leg call.
`RecordingSid`	The unique identifier for the recording.
`RecordingUrl`	The URL of the recorded audio.
`RecordingStatus`	The status of the recording. Possible values are: `in-progress`, `completed`, `absent`.
`RecordingDuration`	The length of the recording, in seconds.
`RecordingChannels`	The number of channels in the final recording file as an integer. Possible values are `1`, `2`.
`RecordingStartTime`	The timestamp of when the recording started.
`RecordingSource`	The initiation method used to create this recording. For recordings initiated when `Record=true` is set on the REST API, `OutboundAPI` will be returned.
`RecordingTrack`	The audio track recorded. Possible values are `inbound`, `outbound`, or `both`.

Parameter	Description
`in-progress`	The recording has started.
`completed`	The recording is complete and available for access.
`absent`	The recording is absent and inaccessible.

Parameters in REST API format
`account_sid` Path	get sid<AC> Not PII The SID of the Account that created the Call resource(s) to read.
`to` Optional	get phone_number PII MTL: 120 DAYS Only show calls made to this phone number, SIP address, Client identifier or SIM SID.
`from` Optional	get phone_number PII MTL: 120 DAYS Only include calls from this phone number, SIP address, Client identifier or SIM SID.
`parent_call_sid` Optional	get sid<CA> Not PII Only include calls spawned by calls with this SID.
`status` Optional	get enum:status Not PII The status of the calls to include. Can be: `queued`, `ringing`, `in-progress`, `canceled`, `completed`, `failed`, `busy`, or `no-answer`.
`start_time` Optional	get date_time_inequality<iso8601> Not PII Only include calls that started on this date. Specify a date as `YYYY-MM-DD` in GMT, for example: `2009-07-06`, to read only calls that started on this date. You can also specify an inequality, such as `StartTime<=YYYY-MM-DD`, to read calls that started on or before midnight of this date, and `StartTime>=YYYY-MM-DD` to read calls that started on or after midnight of this date.
`end_time` Optional	get date_time_inequality<iso8601> Not PII Only include calls that ended on this date. Specify a date as `YYYY-MM-DD` in GMT, for example: `2009-07-06`, to read only calls that ended on this date. You can also specify an inequality, such as `EndTime<=YYYY-MM-DD`, to read calls that ended on or before midnight of this date, and `EndTime>=YYYY-MM-DD` to read calls that ended on or after midnight of this date.

Parameters in REST API format
`account_sid` Path	post sid<AC> Not PII The SID of the Account that created the Call resource(s) to update.
`sid` Path	post sid<CA> Not PII The Twilio-provided string that uniquely identifies the Call resource to update
`url` Optional	post url Not PII The absolute URL that returns the TwiML instructions for the call. We will call this URL using the `method` when the call connects. For more information, see the Url Parameter section in Making Calls.
`method` Optional	post http_method Not PII The HTTP method we should use when calling the `url`. Can be: `GET` or `POST` and the default is `POST`. If an `application_sid` parameter is present, this parameter is ignored.
`status` Optional	post enum:update_status Not PII The new status of the resource. Can be: `canceled` or `completed`. Specifying `canceled` will attempt to hang up calls that are queued or ringing; however, it will not affect calls already in progress. Specifying `completed` will attempt to hang up a call even if it's already in progress.
`fallback_url` Optional	post url Not PII The URL that we call using the `fallback_method` if an error occurs when requesting or executing the TwiML at `url`. If an `application_sid` parameter is present, this parameter is ignored.
`fallback_method` Optional	post http_method Not PII The HTTP method that we should use to request the `fallback_url`. Can be: `GET` or `POST` and the default is `POST`. If an `application_sid` parameter is present, this parameter is ignored.
`status_callback` Optional	post url Not PII The URL we should call using the `status_callback_method` to send status information to your application. If no `status_callback_event` is specified, we will send the `completed` status. If an `application_sid` parameter is present, this parameter is ignored. URLs must contain a valid hostname (underscores are not permitted).
`status_callback_method` Optional	post http_method Not PII The HTTP method we should use when requesting the `status_callback` URL. Can be: `GET` or `POST` and the default is `POST`. If an `application_sid` parameter is present, this parameter is ignored.
`twiml` Optional	post twiml Not PII TwiML instructions for the call Twilio will use without fetching Twiml from url. Twiml and url parameters are mutually exclusive
`time_limit` Optional	post integer Not PII The maximum duration of the call in seconds. Constraints depend on account and configuration.

Parameters

Example 1

Create a Call resource with TwiML

Example 2

Create a Call resource with a URL

Example 3

Create a Call resource and specify a StatusCallback URL

Example 4

Create a Call resource and specify a StatusCallbackEvent

Parameters

Example 1

Fetch a Call resource

Parameters

Example 1

Read multiple Call resources

Example 2

Read multiple Call resources and filter by start date

Example 3

Read multiple Call resources and filter by ‘after start’ date

Example 4

Read multiple Call resources and filter by a period of time

Example 5

Read multiple Call resources and filter by call status and phone number

Example 6

Read multiple Call resources and filter by calls made from a specific device

Parameters

Example 1

Update a Call in progress with TwiML

Example 2

Update a Call in progress with URL

Example 3

Update a Call resource to end the call

Example 4

Update the StatusCallback of an active Call

Parameters

Example 1

Delete a Call resource

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