Websockets

Sanic provides an easy to use abstraction on top of websockets (opens new window).

Routing

Websocket handlers can be hooked up to the router similar to regular handlers.

async def feed(request, ws):
    pass
app.add_websocket_route(feed, "/feed")

@app.websocket("/feed")
async def feed(request, ws):
    pass

Handler

Typically, a websocket handler will want to hold open a loop.

It can then use the send() and recv() methods on the second object injected into the handler.

This example is a simple endpoint that echos back to the client messages that it receives.

@app.websocket("/feed")
async def feed(request, ws):
    while True:
        data = "hello!"
        print("Sending: " + data)
        await ws.send(data)
        data = await ws.recv()
        print("Received: " + data)

Configuration

See configuration section for more details.

app.config.WEBSOCKET_MAX_SIZE = 2 ** 20
app.config.WEBSOCKET_MAX_QUEUE = 32
app.config.WEBSOCKET_READ_LIMIT = 2 ** 16
app.config.WEBSOCKET_WRITE_LIMIT = 2 ** 16
app.config.WEBSOCKET_PING_INTERVAL = 20
app.config.WEBSOCKET_PING_TIMEOUT = 20