Socketioxide: SocketIO & EngineIO Server in Rust

Socket.IO server implementation as a tower layer in Rust

It integrates with any framework based on tower/hyper, such as:

• axum: echo implementation
• warp: echo implementation
• hyper: echo implementation

It takes full advantage of the tower and tower-http ecosystem of middleware, services, and utilities.

⚠️ This crate is under active development and the API is not yet stable.

Features :

• Namespaces
• Rooms
• Handshake data
• Ack and emit with ack
• Binary
• Polling & Websocket transport
• Extensions on socket to add custom data to sockets

Planned features :

• Other adapter to share state between server instances (like redis adapter), currently only the in memory adapter is implemented
• State recovery when a socket reconnects
• SocketIo v3 support (currently only v4 is supported)

Examples :

• Chat app with Axum
• Echo implementation with Axum :

use axum::routing::get;
use axum::Server;
use serde::{Serialize, Deserialize};
use socketioxide::{Namespace, SocketIoLayer};
use serde_json::Value;

#[derive(Debug, Serialize, Deserialize)]
struct MyData {
  pub name: String,
  pub age: u8,
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {

    println!("Starting server");

    let ns = Namespace::builder()
        .add("/", |socket| async move {
            println!("Socket connected on / namespace with id: {}", socket.sid);

            // Add a callback triggered when the socket receive an 'abc' event
            // The json data will be deserialized to MyData
            socket.on("abc", |socket, data: MyData, bin, _| async move {
                println!("Received abc event: {:?} {:?}", data, bin);
                socket.bin(bin).emit("abc", data).ok();
            });

            // Add a callback triggered when the socket receive an 'acb' event
            // Ackknowledge the message with the ack callback
            socket.on("acb", |_, data: Value, bin, ack| async move {
                println!("Received acb event: {:?} {:?}", data, bin);
                ack.bin(bin).send(data).ok();
            });
        })
        .add("/custom", |socket| async move {
            println!("Socket connected on /custom namespace with id: {}", socket.sid);
        })
        .build();

    let app = axum::Router::new()
        .route("/", get(|| async { "Hello, World!" }))
        .layer(SocketIoLayer::new(ns));

    Server::bind(&"127.0.0.1:3000".parse().unwrap())
        .serve(app.into_make_service())
        .await?;

    Ok(())
}