One POST Request,
Instant MQTT
Publish to any MQTT topic with a single HTTP call. No connections to manage, no libraries to install.
When to Use REST API vs MQTT
Choose the right approach for your architecture.
Use REST API When...
- Your backend doesn't need to stay online continuously
- You're using serverless functions (Lambda, Vercel, Workers)
- You can't install MQTT client libraries
- You only need to publish, not subscribe
- You want to avoid connection management complexity
- Cost efficiency matters more than latency
Use Direct MQTT When...
- You need to subscribe and receive messages in real-time
- Your app maintains long-running connections (web apps, mobile)
- Sub-second latency is critical
- You're building a browser app with WebSocket support
- You need QoS 2 exactly-once delivery
- Bidirectional communication is required
Built for Simplicity
Everything you need to publish MQTT messages via HTTP.
Simple HTTP Publishing
Publish MQTT messages with a single POST request. No persistent connections, no MQTT client libraries.
Secure by Default
API key authentication and HTTPS encryption. Scoped permissions per key.
Serverless Native
Stateless API calls work perfectly with AWS Lambda, Vercel, Cloudflare Workers, and cloud functions.
JSON Native
Send structured JSON payloads directly. Automatic serialization, no encoding hassles.
No Connection Overhead
No handshakes, no keepalives, no reconnection logic. Fire and forget.
Scoped API Keys
Create keys with specific topic permissions. Fine-grained access control per integration.
API Endpoints
A simple, RESTful interface to your MQTT broker.
/api/v1/publish /api/v1/publish/batch /api/v1/topics/:topic/retained Quick Examples
Drop these into a serverless function or any HTTP client.
Publish a Message
// Publish via REST API, no MQTT client needed
const response = await fetch('https://api.cloudsignal.app/v1/publish', {
method: 'POST',
headers: {
'Authorization': 'Bearer YOUR_API_KEY',
'Content-Type': 'application/json'
},
body: JSON.stringify({
topic: 'devices/sensor-1/data',
payload: {
temperature: 23.5,
humidity: 65,
timestamp: Date.now()
},
qos: 1
})
})
const result = await response.json()
// { success: true, messageId: "msg_abc123" }Batch Publish
// Batch publish: multiple messages in one request
const response = await fetch('https://api.cloudsignal.app/v1/publish/batch', {
method: 'POST',
headers: {
'Authorization': 'Bearer YOUR_API_KEY',
'Content-Type': 'application/json'
},
body: JSON.stringify({
messages: [
{ topic: 'alerts/system', payload: { type: 'info', msg: 'Backup complete' }},
{ topic: 'metrics/daily', payload: { users: 1250, revenue: 4500 }},
{ topic: 'notifications/user-123', payload: { title: 'Order shipped' }}
]
})
})
// { success: true, published: 3, messageIds: [...] }Real-World Use Cases
How teams use the REST API Bridge to simplify their architecture.
Scheduled Notifications
A scheduled Lambda function runs at 8am, fetches user data, and publishes personalized notifications to each user's topic. No server running 24/7.
Database Triggers
When a new order is created in the database, an edge function fires and publishes to the relevant device topics to trigger UI updates.
CI/CD Pipeline Alerts
After each deployment, a GitHub Action publishes build status to a team channel topic. Connected dashboards update in real-time.
Form Submissions
When a customer fills out a support form, the webhook triggers a serverless function that publishes to an agent's queue topic.
Included in Pro & Scale
The REST API Bridge is bundled with Pro and Scale plans. Free Starter users can add it for $7/month.
- HTTP POST publish
- Batch up to 100 msgs
- 30-day logs
- HTTP POST publish
- Batch up to 100 msgs
- 30-day logs
- Priority processing
- HTTP POST publish
- JSON payloads
- 7-day logs
Enterprise plans include unlimited REST API calls at no additional cost.
View full pricing detailsPublish Your First Message
Get your API key and start publishing in under 5 minutes. No MQTT knowledge required.