Library for building WebSocket servers and clients in Python
Under BSD 3-Clause "New" or "Revised" License
By aaugustin

python python3 websocket websockets websocket-client websocket-server websocket-library

.. image:: logo/horizontal.svg
:width: 480px
:alt: websockets

|licence| |version| |pyversions| |wheel| |tests| |docs|

.. |licence| image:: https://img.shields.io/pypi/l/websockets.svg
:target: https://pypi.python.org/pypi/websockets

.. |version| image:: https://img.shields.io/pypi/v/websockets.svg
:target: https://pypi.python.org/pypi/websockets

.. |pyversions| image:: https://img.shields.io/pypi/pyversions/websockets.svg
:target: https://pypi.python.org/pypi/websockets

.. |wheel| image:: https://img.shields.io/pypi/wheel/websockets.svg
:target: https://pypi.python.org/pypi/websockets

.. |tests| image:: https://img.shields.io/github/checks-status/aaugustin/websockets/main
:target: https://github.com/aaugustin/websockets/actions/workflows/tests.yml

.. |docs| image:: https://img.shields.io/readthedocs/websockets.svg
:target: https://websockets.readthedocs.io/

What is websockets?

websockets is a library for building WebSocket servers_ and clients_ in
Python with a focus on correctness and simplicity.

.. _servers: https://github.com/aaugustin/websockets/blob/main/example/server.py
.. _clients: https://github.com/aaugustin/websockets/blob/main/example/client.py

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. <https://websockets.readthedocs.io/>_

Here's how a client sends and receives messages:

.. copy-pasted because GitHub doesn't support the include directive

.. code:: python

#!/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()


And here's an echo server:

.. code:: python

#!/usr/bin/env python

import asyncio
from websockets import serve

async def echo(websocket):
async for message in websocket:
await websocket.send(message)

async def main():
async with serve(echo, "localhost", 8765):
await asyncio.Future() # run forever


Does that look good?

Get started with the tutorial! <https://websockets.readthedocs.io/en/stable/intro/index.html>_

.. raw:: html

<img align="left" height="150" width="150" src="https://raw.githubusercontent.com/aaugustin/websockets/main/logo/tidelift.png">
<h3 align="center"><i>websockets for enterprise</i></h3>
<p align="center"><i>Available as part of the Tidelift Subscription</i></p>
<p align="center"><i>The maintainers of websockets and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source dependencies you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact dependencies you use. <a href="https://tidelift.com/subscription/pkg/pypi-websockets?utm_source=pypi-websockets&utm_medium=referral&utm_campaign=readme">Learn more.</a></i></p>
<p>(If you contribute to <code>websockets</code> and would like to become an official support provider, <a href="https://fractalideas.com/">let me know</a>.)</p>

Why should I use websockets?

The development of websockets is shaped by four principles:

  1. Simplicity: all you need to understand is msg = await ws.recv() and
    await ws.send(msg); websockets takes care of managing connections
    so you can focus on your application.

  2. 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.

  3. Quality: websockets is heavily tested. Continuous integration fails
    under 100% branch coverage. Also it passes the industry-standard Autobahn

  4. 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
_ and see for yourself.

.. _Read the Docs: https://websockets.readthedocs.io/
.. _handle backpressure correctly: https://vorpus.org/blog/some-thoughts-on-asynchronous-api-design-in-a-post-asyncawait-world/#websocket-servers

Why shouldn't I use websockets?

What else?

Bug reports, patches and suggestions are welcome!

To report a security vulnerability, please use the Tidelift security
_. Tidelift will coordinate the fix and disclosure.

.. _Tidelift security contact: https://tidelift.com/security

For anything else, please open an issue_ or send a pull request_.

.. _issue: https://github.com/aaugustin/websockets/issues/new
.. _pull request: https://github.com/aaugustin/websockets/compare/

Participants must uphold the Contributor Covenant code of conduct_.

.. _Contributor Covenant code of conduct: https://github.com/aaugustin/websockets/blob/main/CODE_OF_CONDUCT.md

websockets is released under the BSD license_.

.. _BSD license: https://github.com/aaugustin/websockets/blob/main/LICENSE