Crate reqwest

Expand description

reqwest

The reqwest crate provides a convenient, higher-level HTTP Client.

It handles many of the things that most people just expect an HTTP client to do for them.

Plain bodies, JSON, urlencoded, multipart
Customizable redirect policy
HTTP Proxies
Uses system-native TLS
Cookies

The reqwest::Client is synchronous, making it a great fit for applications that only require a few HTTP requests, and wish to handle them synchronously.

Additional learning resources include:

Making a GET request

For a single request, you can use the get shortcut method.


let body = reqwest::get("https://www.rust-lang.org")?
    .text()?;

println!("body = {:?}", body);

Additionally, reqwest’s Response struct implements Rust’s Read trait, so many useful standard library and third party crates will have convenience methods that take a Response anywhere T: Read is acceptable.

NOTE: If you plan to perform multiple requests, it is best to create a Client and reuse it, taking advantage of keep-alive connection pooling.

Making POST requests (or setting request bodies)

There are several ways you can set the body of a request. The basic one is by using the body() method of a RequestBuilder. This lets you set the exact raw bytes of what the body should be. It accepts various types, including String, Vec<u8>, and File. If you wish to pass a custom Reader, you can use the reqwest::Body::new() constructor.

let client = reqwest::Client::new();
let res = client.post("http://httpbin.org/post")
    .body("the exact body that is sent")
    .send()?;

Forms

It’s very common to want to send form data in a request body. This can be done with any type that can be serialized into form data.

This can be an array of tuples, or a HashMap, or a custom type that implements Serialize.

// This will POST a body of `foo=bar&baz=quux`
let params = [("foo", "bar"), ("baz", "quux")];
let client = reqwest::Client::new();
let res = client.post("http://httpbin.org/post")
    .form(&params)
    .send()?;

JSON

There is also a json method helper on the RequestBuilder that works in a similar fashion the form method. It can take any value that can be serialized into JSON.

// This will POST a body of `{"lang":"rust","body":"json"}`
let mut map = HashMap::new();
map.insert("lang", "rust");
map.insert("body", "json");

let client = reqwest::Client::new();
let res = client.post("http://httpbin.org/post")
    .json(&map)
    .send()?;

Additional X509 certificates can be configured on a ClientBuilder with the Certificate type.
Client certificates can be add to a ClientBuilder with the Identity type.
Various parts of TLS can also be configured or even disabled on the ClientBuilder.

Optional Features

The following are a list of Cargo features that can be enabled or disabled:

default-tls (enabled by default): Provides TLS support via the native-tls library to connect over HTTPS.
default-tls-vendored: Enables the vendored feature of native-tls.
rustls-tls: Provides TLS support via the rustls library.
socks: Provides SOCKS5 proxy support.
trust-dns: Enables a trust-dns async resolver instead of default threadpool using getaddrinfo.
hyper-011: Provides support for hyper’s old typed headers.