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CometD client for asyncio

Project description


PyPI package Documentation Status Build status Coverage MIT license

aiocometd is a CometD client built using asyncio, implementing the Bayeux protocol.

CometD is a scalable WebSocket and HTTP based event and message routing bus. CometD makes use of WebSocket and HTTP push technologies known as Comet to provide low-latency data from the server to browsers and client applications.


  • Supported transports:
    • long-polling

    • websocket

  • Automatic reconnection after network failures

  • Extensions


import asyncio

from aiocometd import Client

async def chat():
    nickname = "John"

    # connect to the server
    async with Client("") as client:

            # subscribe to channels to receive chat messages and
            # notifications about new members
            await client.subscribe("/chat/demo")
            await client.subscribe("/members/demo")

            # send initial message
            await client.publish("/chat/demo", {
                "user": nickname,
                "membership": "join",
                "chat": nickname + " has joined"
            # add the user to the chat room's members
            await client.publish("/service/members", {
                "user": nickname,
                "room": "/chat/demo"

            # listen for incoming messages
            async for message in client:
                if message["channel"] == "/chat/demo":
                    data = message["data"]
                    print(f"{data['user']}: {data['chat']}")

if __name__ == "__main__":
    loop = asyncio.get_event_loop()

For more detailed usage examples take a look at the command line chat example or for a more complex example with a GUI check out the aiocometd-chat-demo.



0.4.5 (2019-03-14)

  • Fix connection issues when used with reverse proxy servers with cookie based sticky sessions

0.4.4 (2019-02-26)

  • Refactor the websocket transport implementation to use a single connection per client

0.4.3 (2019-02-12)

  • Fix reconnection issue on Salesforce Streaming API

0.4.2 (2019-01-15)

  • Fix the handling of invalid websocket transport responses

  • Fix the handling of failed subscription responses

0.4.1 (2019-01-04)

  • Add documentation links

0.4.0 (2019-01-04)

  • Add type hints

  • Add integration tests

0.3.1 (2018-06-15)

  • Fix premature request timeout issue

0.3.0 (2018-05-04)

  • Enable the usage of third party JSON libraries

  • Fix detection and recovery from network failures

0.2.3 (2018-04-24)

  • Fix RST rendering issues

0.2.2 (2018-04-24)

  • Fix documentation typos

  • Improve examples

  • Reorganise documentation

0.2.1 (2018-04-21)

  • Add PyPI badge to README

0.2.0 (2018-04-21)

  • Supported transports:
    • long-polling

    • websocket

  • Automatic reconnection after network failures

  • Extensions

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