Crate reqwest

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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.

  • Uses system-native TLS
  • Plain bodies, JSON, urlencoded, multipart
  • Customizable redirect policy
  • Proxies
  • Cookies (only rudimentary support, full support is TODO)

The rudimentary cookie support means that the cookies need to be manually configured for every single request. In other words, there’s no cookie jar support as of now. The tracking issue for this feature is available on GitHub.

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.

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()?;

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.
  • hyper-011: Provides support for hyper’s old typed headers.

Modules

An ‘async’ implementation of the reqwest Client.
HTTP header types
multipart/form-data

Structs

The body of a Request.
Represent an X509 certificate.
A Client to make Requests with.
A ClientBuilder can be used to create a Client with custom configuration.
The Errors that may occur when processing a Request.
Represent a private key and X509 cert as a client certificate.
The Request Method (VERB)
Configuration of a proxy that a Client should pass requests to.
An action to perform when a redirect status code is found.
A type that holds information on the next request and previous requests in redirect chain.
A type that controls the policy on how to handle the following of redirects.
A request which can be executed with Client::execute().
A builder to construct the properties of a Request.
A Response to a submitted Request.
An HTTP status code (status-code in RFC 7230 et al.).
A parsed URL record.
Represents a version of the HTTP spec.

Enums

Errors that can occur during parsing.

Traits

A trait to try to convert some type into a Url.

Functions

Shortcut method to quickly make a GET request.

Type Definitions

A Result alias where the Err case is reqwest::Error.