In this guide we’ll cover how to combine Twilio Add-ons with Programmable Voice to use data from Twilio's partners in your C# (ASP.NET MVC) web application. Let's get started!
Twilio Add-ons are pre-integrated third party services that you can use with your Twilio application. Add-ons enhance the responses your application receives from Twilio by including additional data from Twilio’s partners.
In this guide we’ll cover how to combine Twilio Add-ons with Programmable Voice to use data from Twilio's partners in your C# web application. The sample code in this guide will use the Twilio C# SDK and C# (ASP.NET MVC). Let's get started.
Here’s an example that uses the IBM Watson Speech to Text Add-on. The generated transcription will be pushed to the application through a callback from Twilio.
The IBM Watson Speech add-on can convert Twilio audio recordings into text using machine intelligence to combine information about grammar and language structure.
See the Add-ons Catalog for the complete list of available add-ons.
The first stop in using an add-on is your Twilio Console. Log in and navigate to the Add-ons page within the Marketplace section.
Then choose on the add-on you want to enable and click the “Install” button. After accepting the Terms of Service, it will be installed on your account. In this example, we’ll use the IBM Watson Speech to Text Add-on.
Set the “Callback URL” and “Callback Request Method” as appropriate for your public server URL (instructions below).
Pro Tip: you can quickly inspect what Twilio will send to your callback URL using tools like PostBin before you actually set up your server.
If you choose to record voice or video calls, you need to comply with certain laws and regulations, including those regarding obtaining consent to record (such as California’s Invasion of Privacy Act and similar laws in other jurisdictions). Additional information on the legal implications of call recording can be found here.
Notice: Twilio recommends that you consult with your legal counsel to make sure that you are complying with all applicable laws in connection with communications you record or store using Twilio.
Now we’re ready to use the extra data from our add-on in our C# application.
Twilio will include data from all of your add-ons in an “AddOns” field on HTTP requests it makes to your application. The following example demonstrates how to access add-on data within your C# (ASP.NET MVC) application.
The `VoiceController` will receive the call, record the next 10 seconds of the call and redirect the code execution to the `RecordingController` and hangup.
The `RecodingController` will receive a link to recorded data and execute it.
Lastly, the `CallbackController` will kick, receive the recorded data transcription and return on the HTTP response.
This application gets the transcription for the recorded call from IBM Watson Speech to Text Add-on we configured in the Twilio console. You can find a detailed specification of the data structure for an individual add-on within that add-on's page in the catalog.
And that’s it! Try giving your application a call to see your add-on in action. If you've never received a Twilio phone call with C# before, check out our guide on that topic.
We focused on the IBM Watson Speech to Text Add-on in this guide, but you can just as easily use any of the add-ons available in the catalog in your Twilio Console.