# axum
`axum` is a web application framework that focuses on ergonomics and modularity.
[](https://github.com/tokio-rs/axum/actions/workflows/CI.yml)
[](https://crates.io/crates/axum)
[](https://docs.rs/axum)
More information about this crate can be found in the [crate documentation][docs].
## 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<CreateUser>,
) -> 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][readme-example] as well as other example projects in
the [example directory][examples].
See the [crate documentation][docs] 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 a
benchmark [here](https://github.com/programatik29/rust-web-benchmarks).
## Safety
This crate uses `#![forbid(unsafe_code)]` to ensure everything is implemented in
100% safe Rust.
## Minimum supported Rust version
axum's MSRV is 1.54.
## Examples
The [examples] folder contains various examples of how to use `axum`. The
[docs] also have lots of examples
## Getting Help
In the `axum`'s repo we also have a [number of examples][examples] showing how
to put everything together. You're also welcome to ask in the [Discord
channel][chat] or open an [issue] with your question.
## Community projects
See [here][ecosystem] 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][contributing] to help you get involved in the
`axum` project.
## License
This project is licensed under the [MIT license][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.
[readme-example]: https://github.com/tokio-rs/axum/tree/main/examples/readme
[examples]: https://github.com/tokio-rs/axum/tree/main/examples
[docs]: https://docs.rs/axum
[`tower`]: https://crates.io/crates/tower
[`hyper`]: https://crates.io/crates/hyper
[`tower-http`]: https://crates.io/crates/tower-http
[`tonic`]: https://crates.io/crates/tonic
[contributing]: /CONTRIBUTING.md
[chat]: https://discord.gg/tokio
[issue]: https://github.com/tokio-rs/axum/issues/new
[`tower::Service`]: https://docs.rs/tower/latest/tower/trait.Service.html
[ecosystem]: /ECOSYSTEM.md
[license]: /axum/LICENSE