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Guide
Core Concepts
Topics
Features
Ecosystem
API
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Reqwest: Rust HTTP Client Library

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Reqwest is a high-level HTTP client library that simplifies HTTP request handling with many built-in features:

  • Supports both async and blocking APIs
  • Handles various request body types: plain text, JSON, URL-encoded forms, multipart forms
  • Customizable redirect policies
  • HTTP proxy support
  • TLS encryption by default
  • Cookie management

Basic Usage

Making GET Requests

For single requests, use the get convenience method:

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

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

Note: When making multiple requests, it's better to create and reuse a Client to benefit from connection pooling.

let client = reqwest::Client::new();
let res = client.get("https://www.rust-lang.org")
    .send()
    .await?;

Making POST Requests

Set request bodies using the body() method:

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

Form Data

Sending form data is common—any type that can be serialized into form data will work:

// 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()
    .await?;

JSON Data

Easily send JSON data with the json method (requires json feature):

// 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()
    .await?;

Response Handling

Responses can be processed in multiple ways:

let res = client.get("https://www.rust-lang.org").send().await?;

// Get status code
let status = res.status();

// Get response headers
let content_type = res.headers().get("content-type").unwrap();

// Read response body as text
let body = res.text().await?;

// Or parse as JSON
let json: serde_json::Value = res.json().await?;

Advanced Features

Redirect Policies

By default, the client automatically handles HTTP redirects with up to 10 hops. Customize this behavior using ClientBuilder:

let custom_client = reqwest::Client::builder()
    .redirect(reqwest::redirect::Policy::none()) // Disable redirects
    .build()?;

Cookie Support

Enable automatic storage and sending of session cookies via ClientBuilder:

let client = reqwest::Client::builder()
    .cookie_store(true)
    .build()?;

Proxy Configuration

System proxies are enabled by default, reading from environment variables:

  • HTTP_PROXY or http_proxy: Proxy for HTTP connections
  • HTTPS_PROXY or https_proxy: Proxy for HTTPS connections
  • ALL_PROXY or all_proxy: Proxy for both types of connections

Proxies can also be explicitly set:

let proxy = reqwest::Proxy::http("https://secure.example")?;
let client = reqwest::Client::builder()
    .proxy(proxy)
    .build()?;

// Or disable proxies
let client = reqwest::Client::builder()
    .no_proxy()
    .build()?;

TLS Configuration

The client uses TLS by default for HTTPS connections:

// Add custom root certificates
let cert = reqwest::Certificate::from_pem(&cert_bytes)?;
let client = reqwest::Client::builder()
    .add_root_certificate(cert)
    .build()?;

// Configure client certificates
let identity = reqwest::Identity::from_pkcs12_der(&pkcs12_der, "password")?;
let client = reqwest::Client::builder()
    .identity(identity)
    .build()?;

Timeout Settings

Configure request timeouts:

let client = reqwest::Client::builder()
    .timeout(std::time::Duration::from_secs(10))
    .build()?;

Optional Features

Reqwest offers multiple optional features that can be enabled via Cargo:

  • http2 (enabled by default): HTTP/2 support
  • default-tls (enabled by default): TLS support for HTTPS
  • rustls-tls: TLS functionality via rustls
  • blocking: Blocking client API
  • json: JSON serialization/deserialization
  • multipart: Multipart form support
  • cookies: Cookie session support
  • gzip, brotli, deflate, zstd: Response body decompression
  • socks: SOCKS5 proxy support

Blocking API

When async isn't needed, use the blocking API (requires blocking feature):

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

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