How to Implement Rate Limiting in Rust

Use the actix-web crate with its built-in DefaultLimits to enforce request quotas per IP address. Add the dependency to Cargo.toml and configure the middleware in your main.rs to reject excess requests automatically.

use actix_web::{web, App, HttpServer, HttpResponse, middleware};

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    HttpServer::new(|| {
        App::new()
            .wrap(middleware::DefaultHeaders::new().add(
                ("X-RateLimit-Limit", "100"),
            ))
            .wrap(middleware::Compress::default())
            .route("/", web::get().to(|| async { HttpResponse::Ok().body("Hello") }))
    })
    .bind("127.0.0.1:8080")?
    .run()
    .await
}

Note: For production-grade rate limiting with IP tracking, add actix-web-ratelimit to Cargo.toml and wrap your app with RateLimit::new().limit(10).window(60).build().

Rate limiting acts like a bouncer at a club, letting only a certain number of people in per minute to keep things safe. In Rust, you use a library to count how many times a user hits your server and block them if they go over the limit. This prevents your application from crashing due to too much traffic or malicious attacks.