iMessage REST API

The Blooio iMessage REST API lets you send and receive iMessages over plain HTTPS. This guide is a practical tour of the API's resources and conventions so you can integrate with any HTTP client — curl, fetch, requests, axios, or anything else.

What is a REST API for iMessage?

Apple does not expose a public iMessage API. Blooio runs real Apple infrastructure and exposes a standard REST interface on top of it, so any app that can speak HTTP can send iMessages. Every request uses plain JSON and returns predictable, documented response shapes.

Key properties:

• HTTPS only — every request goes to https://backend.blooio.com/v2/api
• Stateless — every request carries a Bearer token; no cookies or sessions
• JSON in, JSON out — no XML, no multipart except for file uploads
• Conventional HTTP verbs — GET, POST, PATCH, DELETE do what you'd expect
• Predictable URLs — /chats/{chatId}/messages, /contacts/{contactId}, /groups/{groupId}/members

Base URL

https://backend.blooio.com/v2/api

All examples in the docs are relative to this base URL.

Authentication

Every request includes a Bearer token in the Authorization header:

curl -X GET https://backend.blooio.com/v2/api/me \
  -H "Authorization: Bearer YOUR_API_KEY"

Get an API key from the Blooio dashboard. See Authentication for details on rotating keys and scoping permissions.

Resources

The REST API is organised into a handful of resources. Each resource is a plural noun at a top-level path.

HTTP verbs

Blooio uses the standard REST verb vocabulary. No surprises, no custom verbs.

Sending a message

The most common REST call — send an iMessage — is a single POST:

curl -X POST 'https://backend.blooio.com/v2/api/chats/%2B15551234567/messages' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"text": "Hello from the REST API"}'

const chatId = encodeURIComponent('+15551234567')

const res = await fetch(
  `https://backend.blooio.com/v2/api/chats/${chatId}/messages`,
  {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${process.env.BLOOIO_API_KEY}`,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({ text: 'Hello from the REST API' })
  }
)

const { message_id } = await res.json()

import os, requests
from urllib.parse import quote

chat_id = quote('+15551234567', safe='')

res = requests.post(
    f'https://backend.blooio.com/v2/api/chats/{chat_id}/messages',
    headers={
        'Authorization': f"Bearer {os.environ['BLOOIO_API_KEY']}",
        'Content-Type': 'application/json',
    },
    json={'text': 'Hello from the REST API'},
)

print(res.json()['message_id'])

Response:

{
  "message_id": "Qm8FhbH3P7R",
  "status": "queued"
}

Request conventions

URL-encoding phone numbers

Phone numbers contain a + which has special meaning in URLs. Always URL-encode the chatId:

// becomes %2B15551234567
const chatId = encodeURIComponent('+15551234567')

Forgetting to encode the + is the single most common REST integration mistake.

Pagination

List endpoints use limit and offset:

curl 'https://backend.blooio.com/v2/api/chats?limit=25&offset=50' \
  -H 'Authorization: Bearer YOUR_API_KEY'

Defaults: limit=25, offset=0. Maximum limit is 100.

Sorting and filtering

Most list endpoints accept sort (e.g. created_at:desc) and a q search parameter. See each endpoint's reference page for supported fields.

Response shape

Every successful response is a JSON object. List endpoints return:

{
  "data": [ ... ],
  "count": 42,
  "limit": 25,
  "offset": 0
}

Single-resource endpoints return the resource directly:

{
  "id": "msg_abc123",
  "text": "Hello",
  "status": "delivered",
  "created_at": "2026-04-19T12:34:56Z"
}

Errors

Errors use standard HTTP status codes and a consistent JSON body:

{
  "error": "invalid_request",
  "message": "text or attachments is required",
  "details": {
    "field": "text"
  }
}

See Error handling for retry strategies.

Idempotency

Send the Idempotency-Key header on POST requests to make them safe to retry:

curl -X POST 'https://backend.blooio.com/v2/api/chats/%2B15551234567/messages' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Idempotency-Key: a1b2c3d4-order-123' \
  -H 'Content-Type: application/json' \
  -d '{"text": "Hello"}'

If the same key is sent twice within 24 hours, Blooio returns the original response without creating a duplicate message. See Idempotency for the full rules.

Rate limits

Rate limits are automatically managed per API key. The current limit is returned on every response:

On 429, honour the Retry-After header (seconds) before retrying.

Webhooks

The REST API's read side is usually backed by webhooks — Blooio POSTs events to a URL you register. Create a webhook:

curl -X POST 'https://backend.blooio.com/v2/api/webhooks' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
    "webhook_url": "https://yourapp.com/hooks/blooio",
    "webhook_type": "all"
  }'

Events include message received, delivered, failed, and reactions. See Webhook events for the full catalogue.

Code examples

Full end-to-end examples live in message-sending basics. For language-specific walkthroughs see:

• Send iMessage with Python
• Send iMessage with Node.js

Next steps

• Quickstart — send your first iMessage in under five minutes
• Authentication — API key management and rotation
• Webhook signatures — verify event authenticity
• API reference — every endpoint, every field