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SSE (EventSource), with bidirectional emulation

Server-Sent Events or EventSource is a well-known HTTP-based transport available in all modern browsers and loved by many developers. It's unidirectional in its nature but with Centrifugo bidirectional emulation layer it may be used as a fallback or alternative to WebSocket.

SSE (EventSource) connection endpoint in Centrifugo is:

/connection/sse
info

This transport is only implemented by our Javascript SDK.

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);
centrifuge.connect()
danger

Make sure allowed_origins are properly configured.

Options​

sse​

Boolean, default: false.

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

config.json
{
    ...
    "sse": true
}

sse_max_request_body_size​

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).