SMS Webhooks and API: Build Custom Integrations

JustCall provides webhooks and API endpoints for SMS, so you can build custom integrations that go beyond the built-in CRM connectors. Receive real-time event notifications, send messages programmatically, and sync SMS data with your own systems.

Available on: Pro plan and above

SMS Webhooks

Webhooks push event data to your application in real time. When an SMS event occurs, JustCall sends an HTTP POST request to your configured endpoint.

Available webhook events

Set up a webhook

1. Go to Settings → Webhooks.
2. Click Add Webhook.
3. Enter your endpoint URL (must be HTTPS).
4. Select the events you want to receive.
5. Click Save.

JustCall sends a test ping to verify your endpoint is reachable.

Webhook payload

Each webhook POST includes:

{
  "event": "sms.received",
  "timestamp": "2026-03-12T14:30:00Z",
  "data": {
    "message_id": "msg_abc123",
    "direction": "inbound",
    "from": "+15125551234",
    "to": "+15125550100",
    "body": "Hi, I'd like to schedule an appointment",
    "media_urls": [],
    "justcall_number": "+15125550100",
    "contact_name": "Sarah Chen",
    "agent_id": null
  }
}

Retry policy

If your endpoint returns a non-2xx status code, JustCall retries:

• 1st retry: 30 seconds
• 2nd retry: 5 minutes
• 3rd retry: 30 minutes
• After 3 failures: webhook is paused. Check Settings → Webhooks to reactivate.

SMS API

Send messages, retrieve conversations, and manage contacts programmatically.

Authentication

All API requests require your JustCall API key and secret:

Authorization: Bearer {api_key}:{api_secret}

Find your API credentials under Settings → API & Webhooks → API Keys.

Send an SMS

POST /api/v2/texts/new
Content-Type: application/json

{
  "from": "+15125550100",
  "to": "+15125551234",
  "body": "Your appointment is confirmed for March 15 at 2 PM."
}

Retrieve conversations

GET /api/v2/texts/list?per_page=20&page=1

Get message details

GET /api/v2/texts/{message_id}

For the complete API reference, visit JustCall's developer documentation under Settings → API & Webhooks → Documentation.

Common Integration Patterns

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• SMS and CRM Integration
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