reqwest-middleware

A crate implementing a wrapper around reqwest to allow for client middleware chains.

This crate provides functionality for building and running middleware but no middleware implementations. This repository also contains a couple of useful concrete middleware crates:

• reqwest-retry: retry failed requests.
• reqwest-tracing: tracing integration, optional opentelemetry support.

Note about browser support: automated tests targeting wasm are disabled. The crate may work with wasm but wasm support is unmaintained. PRs improving wasm are still welcome but you'd need to reintroduce the tests and get them passing before we'd merge it (see https://github.com/TrueLayer/reqwest-middleware/pull/105).

Overview

The reqwest-middleware client exposes the same interface as a plain reqwest client, but ClientBuilder exposes functionality to attach middleware:

# Cargo.toml
# ...
[dependencies]
reqwest = "0.11"
reqwest-middleware = "0.1.6"
reqwest-retry = "0.1.5"
reqwest-tracing = "0.2.3"
tokio = { version = "1.12.0", features = ["macros", "rt-multi-thread"] }

use reqwest_middleware::{ClientBuilder, ClientWithMiddleware};
use reqwest_retry::{RetryTransientMiddleware, policies::ExponentialBackoff};
use reqwest_tracing::TracingMiddleware;

#[tokio::main]
async fn main() {
    // Retry up to 3 times with increasing intervals between attempts.
    let retry_policy = ExponentialBackoff::builder().build_with_max_retries(3);
    let client = ClientBuilder::new(reqwest::Client::new())
        // Trace HTTP requests. See the tracing crate to make use of these traces.
        .with(TracingMiddleware::default())
        // Retry failed requests.
        .with(RetryTransientMiddleware::new_with_policy(retry_policy))
        .build();
    run(client).await;
}

async fn run(client: ClientWithMiddleware) {
    client
        .get("https://truelayer.com")
        .header("foo", "bar")
        .send()
        .await
        .unwrap();
}

License

Third-party middleware

The following third-party middleware use reqwest-middleware:

• reqwest-conditional-middleware - Per-request basis middleware
• http-cache - HTTP caching rules
• reqwest-cache - HTTP caching
• aliri_reqwest - Background token management and renewal
• http-signature-normalization-reqwest (not free software) - HTTP Signatures
• reqwest-chain - Apply custom criteria to any reqwest response, deciding when and how to retry.