REST API

Project Blue API

Send iMessages and SMS directly from your application. Integrate messaging into your CRM, workflows, or custom tools with a single API call.

Authentication

All API requests require a Bearer token in the Authorization header. You can generate API keys from within your Project Blue dashboard under Settings → API Keys.

Authorization: Bearer YOUR_API_KEY

Send Message

Send a message to a phone number via iMessage or SMS. If the recipient has iMessage, the message is delivered as an iMessage (blue bubble). Otherwise, it falls back to SMS automatically.

Request Body

The phone parameter is flexible — we accept formats like (555) 123-4567, 555.123.4567, +15551234567, and more. All numbers are normalized to E.164 format before sending.

Example Request

curl -X POST https://api.tryprojectblue.com/send-api-message \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "message": "Hey! Just following up on our conversation.",
    "phone": "+15551234567"
  }'

Example with Media Attachment

curl -X POST https://api.tryprojectblue.com/send-api-message \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "message": "Check out this property!",
    "phone": "+15551234567",
    "mediaAttachmentUrl": "https://example.com/property-photo.jpg"
  }'

Example with AI Voice Memo

curl -X POST https://api.tryprojectblue.com/send-api-message \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "message": "Hey, wanted to quickly touch base about your appointment tomorrow.",
    "phone": "+15551234567",
    "enableAiVoiceMemo": true
  }'

Success Response

{
  "success": true,
  "messageId": "msg_abc123def456"
}

Supported Media Types

Use the mediaAttachmentUrl field to send rich media with your messages. The following formats are supported:

Images

Videos

Contact Cards

Voice Memos & Audio

Use audioAttachmentUrl to send audio files as voice memos. The following formats are supported:

Webhooks

Webhooks let you receive real-time notifications when messages are sent or received. Configure webhooks from within the Project Blue dashboard alongside your API keys.

Configuration

In the Project Blue app, you can:

• Paste the webhook URL you want to receive events at

• Toggle whether the webhook fires for outbound messages, inbound messages, or both

• Send test payloads to verify your endpoint is working

Webhook Payload

Every webhook event delivers the same payload structure. The direction field indicates whether the message was inbound or outbound.

Example — Inbound

{
  "message": "Yes, I'm interested! When can we schedule?",
  "destination": "+15551234567",
  "receivedAt": "2026-03-04T18:30:00.000Z",
  "direction": "inbound",
  "messageId": 456,
  "guid": "sample-guid-1234",
  "linePhoneNumber": "+15559876543"
}

Example — Outbound

{
  "message": "Great! Let's book you in for Thursday at 2pm.",
  "destination": "+15551234567",
  "receivedAt": "2026-03-04T18:31:00.000Z",
  "direction": "outbound",
  "messageId": 789,
  "guid": "sample-guid-5678",
  "linePhoneNumber": "+15559876543"
}

Error Handling

The API uses standard HTTP status codes. All error responses include a JSON body with an error field describing what went wrong.

{
  "error": "Missing or invalid Authorization header"
}