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POST
Create Mid-call Action
This endpoint allows you to create a new Mid-call Action that can be used by your AI assistants to interact with external APIs during calls.

Body Parameters

The public API creates HTTP Mid-call Actions. Automation Platform Mid-call Actions (which generate a linked flow) are created from the dashboard. Mid-call Action values support dynamic variables — use {param} for AI-extracted parameters in the URL, and {{variable}} (e.g. {{customer_phone}}) in the URL, header values, and static field values.
name
string
required
Mid-call Action name — letters, numbers and underscores, starting with a letter or underscore (max 64 characters, e.g. get_weather, book_appointment)
description
string
required
Detailed explanation of when and how the AI should use this Mid-call Action (max 255 characters)
endpoint
string
required
Valid URL of the API endpoint to call (max 2048 characters)
method
string
required
HTTP method: GET, POST, PUT, PATCH, or DELETE
body_format
string
How the request body is encoded for write methods (POST/PUT/PATCH): json (default) or form (application/x-www-form-urlencoded)
timeout
integer
Request timeout in seconds (1-30, default: 10)
headers
array
HTTP headers to send with the request
static_fields
array
Fixed key/value pairs always sent with the request (the AI never changes them)
schema
array
Parameters that the AI will extract from conversation and send to the endpoint

Response Fields

message
string
Success message
data
object
The created Mid-call Action object

Attaching Mid-call Actions to Assistants

After creating a Mid-call Action, attach it to an assistant to use it during calls. Manage assignments through the Assistant API:
  • Create Assistant — Use the tool_ids parameter to attach Mid-call Actions when creating an assistant
  • Update Assistant — Use the tool_ids parameter to add, remove, or replace Mid-call Actions on an existing assistant
Need a whole toolset instead of building HTTP actions one by one? Connect an external MCP server — tools are discovered automatically. See MCP Servers.