mojo-websockets is a lightweight library for handling WebSocket connections in Mojo.

It aims to provide an similar interface as the python-websockets package for creating WebSocket servers and clients, with additional features for enhanced usability.

Disclaimer ⚠️

This software is in a early stage of development. Please DO NOT use yet for production ready services.

Features

• WebSocket Server and Client: Supports creating both WebSocket servers and clients.
• Compatibility: API designed to be intuitive for developers familiar with the Python websockets library.
• Sans/IO Layer: Implements a WebSocket Sans/IO layer pure Mojo and performs no I/O of its own.

For a complete listing, see the features document.

Installation

1. Install pixi

2. Add the WebSockets Package (at the top level of your project):

   pixi add websockets
         
   
         
   
       

Example of usage

Server side

from websockets.sync.server import serve, WSConnection

fn on_message(conn: WSConnection, data: Span[Byte]) raises -> None:
    str_received = String(data)
    print("<<< ", str_received)
    conn.send_text(str_received)
    print(">>> ", str_received)

fn main() raises:
    with serve[on_message]("127.0.0.1", 8000) as server:
        server.serve_forever()
      

      

    

Client side

from websockets.sync.client import connect

fn send_and_receive(msg: String) raises:
    with connect("ws://127.0.0.1:8000") as client:
        client.send_text(msg)
        print(">>> ", msg)
        response = client.recv_text()
        print("<<< ", response)

fn main() raises:
    send_and_receive("Hello world!")
      

      

    

TODO

• Asynchronous non-blocking communication (implemented in the io_uring branch)
• Implement automatic reconnection for clients
• Make sure it passes all the tests in Autobahn|Testsuite
• Implement subprotocols and extensions
• Optimize performance for high-concurrency scenarios
• TLS support

See all the remaining features in the features document.

Contributing

Contributions are welcome! If you'd like to contribute, please follow the contribution guidelines in the CONTRIBUTING.md file in the repository.

Acknowledgments

We have taken a lot of code from the amazing lightbug_http project.

Also, we took inspiration and some code from the python-websockets project, specially for implementing the WebSocket Sans/IO layer and their tests.

License

mojo-websockets is licensed under the MIT license.