Custom Headers: Actix Web Documentation

# Custom Headers

You often need to attach headers to responses, such as cache controls, custom identifiers, or cookies.

#Modifying the Response

Use the insert_header or append_header methods on the HttpResponseBuilder.

code_blocksrust

use actix_web::{get, HttpResponse, Responder};
use actix_web::http::header;

#[get("/data")]
async fn get_data() -> impl Responder {
    HttpResponse::Ok()
        .insert_header((header::CACHE_CONTROL, "public, max-age=3600"))
        .insert_header(("X-Custom-Identifier", "12345"))
        .body("Cached data")
}

#typed Headers

Actix Web leverages the http::header module for strongly typed standard header names, reducing the risk of typos compared to string literals.

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Reference Implementation

The following code snippet demonstrates the authoritative pattern for this documentation.

src/main.rs

Edition 2024

1use actix_web::{get, App, HttpServer, HttpResponse, Responder};
2 
3#[get("/headers")]
4async fn custom_headers() -> impl Responder {
5    HttpResponse::Ok()
6        .insert_header(("X-RateLimit-Limit", "100"))
7        .body("Header set")
8}
9 
10#[actix_web::main]
11async fn main() -> std::io::Result<()> {
12    HttpServer::new(|| App::new().service(custom_headers))
13        .bind(("127.0.0.1", 8080))?
14        .run()
15        .await
16}

Custom Headers

#Modifying the Response

#typed Headers

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Reference Implementation

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