websockets
is a library for building WebSocket servers and clients in Python with a focus on correctness and simplicity.
Built on top of asyncio
, Python's standard asynchronous I/O framework, it provides an elegant coroutine-based API.
Documentation is available on Read the Docs.
Here's how a client sends and receives messages:
#!/usr/bin/env python
import asyncio
from websockets import connect
async def hello(uri):
async with connect(uri) as websocket:
await websocket.send("Hello world!")
await websocket.recv()
asyncio.run(hello("ws://localhost:8765"))
And here's an echo server:
#!/usr/bin/env python
import asyncio
from websockets import serve
async def echo(websocket, path):
async for message in websocket:
await websocket.send(message)
async def main():
async with serve(echo, "localhost", 8765):
await asyncio.Future() # run forever
asyncio.run(main())
Does that look good?
Get started with the tutorial!
Available as part of the Tidelift Subscription
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(If you contribute to websockets
and would like to become an official support provider, let me know.)
The development of websockets
is shaped by four principles:
- Simplicity: all you need to understand is
msg = await ws.recv()
andawait ws.send(msg)
;websockets
takes care of managing connections so you can focus on your application. - Robustness:
websockets
is built for production; for example it was the only library to handle backpressure correctly before the issue became widely known in the Python community. - Quality:
websockets
is heavily tested. Continuous integration fails under 100% branch coverage. Also it passes the industry-standard Autobahn Testsuite. - Performance: memory usage is configurable. An extension written in C accelerates expensive operations. It's pre-compiled for Linux, macOS and Windows and packaged in the wheel format for each system and Python version.
Documentation is a first class concern in the project. Head over to Read the Docs and see for yourself.
- If you prefer callbacks over coroutines:
websockets
was created to provide the best coroutine-based API to manage WebSocket connections in Python. Pick another library for a callback-based API. - If you're looking for a mixed HTTP / WebSocket library:
websockets
aims at being an excellent implementation of6455
: The WebSocket Protocol and7692
: Compression Extensions for WebSocket. Its support for HTTP is minimal — just enough for a HTTP health check. - If you want to use Python 2:
websockets
builds uponasyncio
which only works on Python 3.websockets
requires Python ≥ 3.7.
Bug reports, patches and suggestions are welcome!
To report a security vulnerability, please use the Tidelift security contact. Tidelift will coordinate the fix and disclosure.
For anything else, please open an issue or send a pull request.
Participants must uphold the Contributor Covenant code of conduct.
websockets
is released under the BSD license.