axum

axum is a web application framework that focuses on ergonomics and modularity.

More information about this crate can be found in the crate documentation.

High level features

• Route requests to handlers with a macro free API.
• Declaratively parse requests using extractors.
• Simple and predictable error handling model.
• Generate responses with minimal boilerplate.
• Take full advantage of the [tower] and [tower-http] ecosystem of middleware, services, and utilities.

In particular the last point is what sets axum apart from other frameworks. axum doesn't have its own middleware system but instead uses [tower::Service]. This means axum gets timeouts, tracing, compression, authorization, and more, for free. It also enables you to share middleware with applications written using [hyper] or [tonic].

Usage example

```rust use axum::{ routing::{get, post}, http::StatusCode, response::IntoResponse, Json, Router, }; use serde::{Deserialize, Serialize}; use std::net::SocketAddr;

[tokio::main]

async fn main() { // initialize tracing tracing_subscriber::fmt::init();

// build our application with a route
let app = Router::new()
    // `GET /` goes to `root`
    .route("/", get(root))
    // `POST /users` goes to `create_user`
    .route("/users", post(create_user));

// run our app with hyper
// `axum::Server` is a re-export of `hyper::Server`
let addr = SocketAddr::from(([127, 0, 0, 1], 3000));
tracing::debug!("listening on {}", addr);
axum::Server::bind(&addr)
    .serve(app.into_make_service())
    .await
    .unwrap();

}

// basic handler that responds with a static string async fn root() -> &'static str { "Hello, World!" }

async fn create_user( // this argument tells axum to parse the request body // as JSON into a CreateUser type Json(payload): Json, ) -> impl IntoResponse { // insert your application logic here let user = User { id: 1337, username: payload.username, };

// this will be converted into a JSON response
// with a status code of `201 Created`
(StatusCode::CREATED, Json(user))

}

// the input to our create_user handler

[derive(Deserialize)]

struct CreateUser { username: String, }

// the output to our create_user handler

[derive(Serialize)]

struct User { id: u64, username: String, } ```

You can find this example as well as other example projects in the example directory.

See the crate documentation for way more examples.

Performance

axum is a relatively thin layer on top of [hyper] and adds very little overhead. So axum's performance is comparable to [hyper]. You can find benchmarks here and here.

Safety

This crate uses #![forbid(unsafe_code)] to ensure everything is implemented in 100% safe Rust.

Minimum supported Rust version

axum's MSRV is 1.56.

Examples

The [examples] folder contains various examples of how to use axum. The [docs] also provide lots of code snippets and examples. For full-fledged examples, check out community-maintained [showcases] or [tutorials].

Getting Help

In the axum's repo we also have a number of examples showing how to put everything together. Community-maintained [showcases] and [tutorials] also demonstrate how to use axum for real-world applications. You're also welcome to ask in the Discord channel or open an [issue] with your question.

Community projects

See here for a list of community maintained crates and projects built with axum.

Contributing

:balloon: Thanks for your help improving the project! We are so happy to have you! We have a contributing guide to help you get involved in the axum project.

License

This project is licensed under the MIT license.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in axum by you, shall be licensed as MIT, without any additional terms or conditions.