Axum

Enable the axum feature and mount the auth router at its configured base path. This example also protects /profile with a session extractor:

use crate::auth_schema::AppAuthSchema;
use axum::{Router, routing::get};
use better_auth::BetterAuth;
use better_auth::integrations::axum::{AxumIntegration, CurrentSession};
use better_auth::prelude::AuthUser;
use std::sync::Arc;

async fn profile(session: CurrentSession<AppAuthSchema>) -> String {
    format!("Hello, {}", session.user.id())
}

fn router(auth: Arc<BetterAuth<AppAuthSchema>>) -> Router {
    Router::new()
        .nest("/api/auth", auth.clone().axum_router())
        .route("/profile", get(profile))
        .with_state(auth)
}

CurrentSession returns HTTP 401 when no valid session exists. Use OptionalSession for routes that also serve anonymous visitors.

Application state

If your application has its own state, implement FromRef so the auth instance and session extractors can read it:

use crate::auth_schema::AppAuthSchema;
use axum::{Router, extract::FromRef};
use better_auth::BetterAuth;
use better_auth::integrations::axum::AxumIntegration;
use std::sync::Arc;

#[derive(Clone)]
struct AppState {
    auth: Arc<BetterAuth<AppAuthSchema>>,
}

impl FromRef<AppState> for Arc<BetterAuth<AppAuthSchema>> {
    fn from_ref(state: &AppState) -> Self {
        state.auth.clone()
    }
}

fn router(state: AppState) -> Router {
    Router::new()
        .nest(
            "/api/auth",
            state.auth.clone().axum_router_with_state::<AppState>(),
        )
        .with_state(state)
}

Request lifetime

Axum supervises accepted, fully buffered auth requests, so dispatch can continue after a client disconnects. Keep the runtime alive while requests drain; process shutdown can still cancel them.

See installation for a runnable server.