Set the User-Agent in a HTTP request using Rust reqwest

Dependencies

examples/reqwest-set-user-agent/Cargo.toml

[package]
name = "reqwest-set-user-agent"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
reqwest = { version = "0.11", features = ["blocking"] }

The code

examples/reqwest-set-user-agent/src/main.rs

use reqwest::header::USER_AGENT;

fn main() {
    let client = reqwest::blocking::Client::new();

    let res = client
    .get("http://httpbin.org/headers")
    .send().unwrap();
    println!("{}", res.text().unwrap());

    let res = client
    .get("http://httpbin.org/headers")
    .header(USER_AGENT, "Rust Maven 1.42")
    .send().unwrap();
    println!("{}", res.text().unwrap());
}

The output

{
  "headers": {
    "Accept": "*/*",
    "Host": "httpbin.org",
    "X-Amzn-Trace-Id": "Root=1-65b23d5c-7291d26c5121b8d160a837f9"
  }
}

{
  "headers": {
    "Accept": "*/*",
    "Host": "httpbin.org",
    "User-Agent": "Rust Maven 1.42",
    "X-Amzn-Trace-Id": "Root=1-65b23d5c-1376c1c654589f201d8f958c"
  }
}