So I’m trying to write authentication middleware for my axum server. I used to authenticate user with access token in every route instead of using middleware. But when I tried to create one, it doesn’t work.

main.rs

#[derive(Debug, Clone)]
pub struct AppState {
    pub auth_config: config::Auth,
    pub pool: Pool<MySql>,
    pub projects: config::Projects,
}

let user_routes = Router::new()
        .route("/email", patch(patch_email))
        .route("/password", patch(patch_password))
        .route("/", delete(delete_user))
        .route("/", get(get_user))
        .route("/lastLogin", post(handlers::last_login))
        .layer(axum::middleware::from_fn_with_state(
            state.clone(),
            middleware::auth,
        ));

let listener = tokio::net::TcpListener::bind("0.0.0.0:8001")
        .await
        .expect("Failed to bind auth");
    axum::serve(listener, base_router.into_make_service())
        .await
        .unwrap();

So as you can see here I have AppState with couple of user routes that need authentication, and then I have server initialization. Below routes I have a layer that is using from_fn_with_state function where I pass my state and middleware::auth function

middleware.rs

use axum::{
    extract::{Request, State},
    http::{HeaderMap, StatusCode},
    middleware::Next,
    response::Response,
};
use tools::tokens::AccessToken;

use crate::AppState;

pub async fn auth(
    State(state): State<AppState>,
    headers: HeaderMap,
    mut request: Request,
    next: Next,
) -> Result<Response, StatusCode> {
    match AccessToken::from_headers(&headers) {
        Some(token) => {
            // Check if token is valid
            // If valid, proceed to the next middleware or handler
            match token.decode(&state.auth_config.secret).await {
                Ok(c) => {
                    request.extensions_mut().insert(c.id).unwrap();
                    Ok(next.run(request).await)
                },
                Err(_) => Err(StatusCode::UNAUTHORIZED),
            }
        }
        None => {
            // Return unauthorized response if token is not valid
            Err(StatusCode::UNAUTHORIZED)
        }
    }
}

And this is auth function that validates token and passes uid into request

When I put it all together and try to build the project, it shows me this error:

the trait bound `axum::middleware::FromFn<fn(axum::extract::State<AppState>, axum::http::HeaderMap, axum::http::Request<axum::body::Body>, Next) -> impl std::future::Future<Output = Result<axum::http::Response<axum::body::Body>, axum::http::StatusCode>> {auth}, Arc<AppState>, Route, _>: Service<axum::http::Request<axum::body::Body>>` is not satisfied
the following other types implement trait `Service<Request>`:
  axum::middleware::FromFn<F, S, I, (T1, T2)>...
main.rs(47, 10): required by a bound introduced by this call
mod.rs(278, 21): required by a bound in `axum::Router::<S>::layer`

How can I fix this?