#data-channel #web-rtc #p2p #signaling-server #send-receive


Easy-to-use wrapper for WebRTC DataChannels peer-to-peer connections written in Rust and compiling to WASM

5 releases

0.4.1 Oct 3, 2022
0.4.0 Mar 2, 2022
0.3.2 Feb 7, 2022
0.3.1 Feb 7, 2022
0.3.0 Feb 7, 2022

#293 in WebAssembly

37 downloads per month



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crates.io docs.rs CI coverage status APACHE licensed MIT licensed pre-commit

This crate provides an easy-to-use wrapper around WebRTC and DataChannels for a peer-to-peer connections.


As creator of agar.io famously stated WebRTC is hard. This library aims to help, by abstracting away all the setup, and providing a simple way to send and receive messages over the data channel.

It's as easy as providing address to a signaling server instance from accompanying crate and specifying two callbacks. One that specifies what should happen when a connection is established, and one for when a message is received. After that you can send messages back and forth without worrying about the implementation details.

Library contains three network topologies, one-to-one, which creates an equal connection between two peers, one-to-many, which specifies a host and arbitrary number of clients and many-to-many that creates connection for each pair of peers and allows sending messages to any of them.

For a "production ready" apps built with this library check out either Live Document or Footballers.


This example shows two peers sending ping and pong messages to each other.

use wasm_peers::ConnectionType;
use wasm_peers::one_to_one::NetworkManager;
use web_sys::console;

// there must be a signaling server from accompanying crate running on this port
const SIGNALING_SERVER_URL: &str = "ws://";

fn main() {
    // there must be some mechanism for exchanging session ids between peers
    let session_id = SessionId::new("some-session-id".to_string());
    let mut peer1 = NetworkManager::new(

    let peer1_clone = peer1.clone();
    let peer1_on_open = move || peer1_clone.send_message("ping!").unwrap();
    let peer1_on_message = {
        move |message| {
            console::log_1(&format!("peer1 received message: {}", message).into());
    peer1.start(peer1_on_open, peer1_on_message).unwrap();

    let mut peer2 = NetworkManager::new(
    let peer2_on_open = || { /* do nothing */ };
    let peer2_clone = peer2.clone();
    let peer2_on_message = {
        let peer2_received_message = peer2_received_message.clone();
        move |message| {
            console::log_1(&format!("peer2 received message: {}", message).into());
    peer2.start(peer2_on_open, peer2_on_message).unwrap();

For examples of other topologies check out the docs.


  • Add tests
  • Improve error handling
  • Introduce alternative API with futures
  • Add possibility to pass video/audio streams over established connection

Version History

  • 0.4
    • MiniServer callbacks don't accept UserId argument now (it'd always be hosts)
    • Fix documentation tests so that they compile
  • 0.3
    • Initial release to the public

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This project is licensed under either of


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.


Tomasz Karwowski LinkedIn


These projects helped me grasp WebRTC in Rust:

Also, special thanks to the guys with whom I did my B.Eng. thesis.


~197K SLoC