Protocols
Cloudflare Workers support the following protocols and interfaces:
| Protocol | Inbound | Outbound |
|---|---|---|
| HTTP / HTTPS | Handle incoming HTTP requests using the fetch() handler | Make HTTP subrequests using the fetch() API |
| Direct TCP sockets | Support for handling inbound TCP connections is coming soon ↗ | Create outbound TCP connections using the connect() API |
| WebSockets | Accept incoming WebSocket connections using the WebSocket API, or with MQTT over WebSockets (Pub/Sub) | MQTT over WebSockets (Pub/Sub) |
| MQTT | Handle incoming messages to an MQTT broker with Pub Sub | Support for publishing MQTT messages to an MQTT topic is coming soon |
| HTTP/3 (QUIC) | Accept inbound requests over HTTP/3 ↗ by enabling it on your zone in Speed > Optimization > Protocol Optimization area of the Cloudflare dashboard ↗. | |
| SMTP | Use Email Workers to process and forward email, without having to manage TCP connections to SMTP email servers | Email Workers |