Introduction

The Linq Partner API is a RESTful API at https://api.linqapp.com/api/partner/v3 that provides programmatic access to iMessage, RCS, and SMS messaging infrastructure.

New to Linq? Start with the Quickstart to send your first message in under 5 minutes, or explore the API Reference for the complete endpoint specification.

To use the Linq Partner API, you’ll need:

• A bearer token provisioned by your Linq representative
• One or more phone numbers assigned to your account
• An endpoint URL for receiving webhooks (optional but recommended)

For step-by-step setup, see Quickstart.

The Linq Partner API supports a wide range of messaging use cases:

• Customer support — Route conversations, send rich media, and integrate with your support stack
• Sales engagement — Personalized outreach with read receipts and delivery tracking
• Appointment reminders — Automated notifications with confirmation workflows
• Order notifications — Shipping updates, delivery confirmations, and feedback collection
• AI-powered agents — Build conversational AI that communicates over iMessage, RCS, and SMS

See open-source examples for real-world implementations.

All requests require a bearer token in the Authorization header:

Authorization: Bearer YOUR_TOKEN

For details on token management and security best practices, see Authentication.

Send a message with a single API call:

curl -X POST https://api.linqapp.com/api/partner/v3/chats \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "+12223334444",
    "to": ["+15556667777"],
    "message": {
      "parts": [
        { "type": "text", "value": "Hello from Linq!" }
      ]
    }
  }'

• Phone numbers must be in E.164 format: +12223334444
• Email addresses use standard format: [email protected]
• No spaces, dashes, or parentheses in phone numbers