Error 400: "Bad Request" When Using the HTTP Request Widget – Twilio Support

Issue

With Twilio Studio, Flows can trigger other Flows by several mechanisms, including a Run Subflow widget or by making use of the Twilio API/SDK to trigger a Flow Execution in a Twilio Function with a Run Function widget.

However, using a Make HTTP Request widget to POST to another Flow URL results in a 400 Bad Request error if given a Request Body containing To/From addresses, e.g. "To=+1...&From=MG...". How can this error be avoided?

Product

Twilio Studio

Environment

Twilio Console

Resolution

Instead of specifying the Request Body, enter the "To" and "From" fields as HTTP Parameters.

You will want to ensure:

The Request Method is set to "POST"
The Request URL is the Flow URL to be triggered, e.g. "https://studio.twilio.com/v2/Flows/FW.../Executions"
The Content Type is set to "Form URL Encoded"
"Authenticate With Twilio" is checked

Your receiving Flow should include a "REST API" Trigger (Start) widget to handle the request from the requesting Flow.

Additional Information

You can find more details on configuration for the Make HTTP Request widget here.