How to implement health check endpoint in Rust

Use the axum web framework to define a route that returns a 200 OK status with a JSON payload indicating the service is healthy.

use axum::{routing::get, Router};

async fn health_check() -> &'static str {
    "OK"
}

#[tokio::main]
async fn main() {
    let app = Router::new().route("/health", get(health_check));
    axum::Server::bind(&"0.0.0.0:3000".parse().unwrap())
        .serve(app.into_make_service())
        .await
        .unwrap();
}

Add axum = "0.7" and tokio = { version = "1", features = ["full"] } to your Cargo.toml.

A health check endpoint is a specific URL your server exposes to tell external systems if it is running correctly. It acts like a digital heartbeat, returning a simple 'I'm alive' signal so load balancers or monitoring tools know not to send traffic to a broken server.