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SSE (EventSource), with bidirectional emulation

SSE (EventSource) connection endpoint in Centrifugo is:


This transport is only implemented by our Javascript SDK at this point – as it mostly makes sense as a fallback for WebSocket to have real-time connection in an environment where WebSocket is unavailable. These days those envs are mostly corporate networks which can block WebSocket traffic (even TLS-based).

Here is an example how to use JavaScript SDK with WebSocket as the main transport and SSE transport fallback:

Use SSE with bidirectional emulation as a fallback for WebSocket in JS SDK
const transports = [
transport: 'websocket',
endpoint: 'ws://localhost:8000/connection/websocket'
transport: 'sse',
endpoint: 'http://localhost:8000/connection/sse'
const centrifuge = new Centrifuge(transports);

Make sure allowed_origins are properly configured.



Boolean, default: false.

Enables SSE (EventSource) endpoint. And enables emulation endpoint (/emulation by default) to accept emulation HTTP requests from clients.

"sse": true


Default: 65536 (64KB)

Maximum allowed size of a initial HTTP POST request in bytes when using HTTP POST requests to connect (browsers are using GET so it's not applied).