Webhooks

Overview

Webhooks allow you to receive real-time notifications when calls are completed. When a call ends, CallCow will send a POST request to your configured webhook URL with detailed information about the call.

Setting Up Webhooks

You can create a webhook in the Integration tab. Once you have created a webhook, you can update your custom workflow metadata to use the webhook.

Payload Format

When a call completes, you’ll receive a POST request with a JSON payload containing the following fields:

{
  "call_id": "e0f4c895-e3ea-416a-a98a-578e82868473",
  "workflow_id": "008bda4d-b467-4f55-a8ed-803b3d1d69d5",
  "workflow_name": "calendly test (Copy)",
  "phone_number_from": "browser",
  "phone_number_to": "browser",
  "call_status": "not_picked_up",
  "call_summary": "User and assistant exchange greetings, with assistant introducing themselves as Alex.",
  "messages": [
    {
      "role": "user",
      "content": "Hi"
    },
    {
      "role": "assistant",
      "content": "\nHello. Thank you for answering. My name is Alex."
    },
    {
      "role": "user",
      "content": "Hello?"
    },
    {
      "role": "assistant",
      "content": "Yes yes"
    }
  ],
  "context": "{\"name\": \"YiMing HAN\", \"email\": \"hanyiming1995@gmail.com\", \"number\": \"+14165551234\"}",
  "form_fills": [
    {
      "title": "Form Title",
      "values": {
        "Email": "xxx@gmail.com",
        "Phone Number": "+1416xxx1234",
        "Options": null
      }
    }],
  "created_at": "2026-01-30T14:48:36.371886"
}

Field Reference

Field	Type	Description
`call_id`	string	Unique identifier for the call
`workflow_id`	string	ID of the workflow that handled the call
`workflow_name`	string	Name of the workflow
`phone_number_from`	string	The originating phone number (or `browser` for web calls)
`phone_number_to`	string	The destination phone number (or `browser` for web calls)
`call_status`	string	Status of the call (e.g., `success`, `not_picked_up`)
`call_summary`	string	AI-generated summary of the call
`messages`	array	Full conversation transcript with `role` and `content` for each message
`context`	string	JSON string containing custom context data passed to the workflow (e.g., name, email, phone number)
`form_fills`	array	Array of forms filled out during the call, where each entry contains a `title` (string) and `values` (object mapping field names to values or null). This will only be included if you have forms in your workflow.
`created_at`	string	ISO 8601 timestamp when the call was created

Handling Webhooks

Your webhook endpoint should:

Accept POST requests with JSON content
Respond with a 2xx status code to acknowledge receipt
Process the webhook asynchronously if needed to avoid timeouts

Example Handler (Node.js)

app.post('/webhook/callcow', (req, res) => {
  const payload = req.body;

  console.log('Call completed:', payload.call_id);
  console.log('Status:', payload.call_status);
  console.log('Summary:', payload.call_summary);

  // Parse context if needed
  const context = JSON.parse(payload.context);
  console.log('Caller:', context.name);

  // Process the webhook data
  // e.g., update your CRM, send notifications, etc.

  res.status(200).send('OK');
});

Best Practices

Handle duplicates: Implement idempotency using the call_id field to handle potential duplicate deliveries
Respond quickly: Return a 2xx response promptly and process data asynchronously
Debug and Verify: Webhook works on browser calls as well. So as soon as you updated your webhook you can trigger a call in your browser test it.

API documentation

Endpoints

Webhooks

Overview

Setting Up Webhooks

Payload Format

Field Reference

Handling Webhooks

Example Handler (Node.js)

Best Practices

​Overview

​Setting Up Webhooks

​Payload Format

​Field Reference

​Handling Webhooks

​Example Handler (Node.js)

​Best Practices

Overview

Setting Up Webhooks

Payload Format

Field Reference

Handling Webhooks

Example Handler (Node.js)

Best Practices