Introduction

aioduct is an async-native Rust HTTP client built directly on hyper 1.x — with no hyper-util dependency and no legacy APIs.

Motivation

The Rust HTTP client ecosystem has a gap:

• reqwest depends on hyper-util’s legacy::Client, which wraps hyper 0.x-style patterns over hyper 1.x. It carries years of backwards-compatibility baggage.
• hyper-util itself labels its client as “legacy” — the hyper team acknowledges it’s not the right long-term answer.
• hyper 1.x was redesigned to be a minimal HTTP protocol engine with clean connection-level primitives (hyper::client::conn::http1, hyper::client::conn::http2), but no production client uses it this way today.

aioduct fills this gap: a production-quality HTTP client that uses hyper 1.x the way it was intended — as a protocol engine you drive yourself, with your own connection pool, TLS, and runtime integration.

Design Principles

1. No hyper-util — custom executor and IO adapters directly against hyper::rt traits. ~50 lines each, zero legacy baggage.
2. No default runtime — the core crate is pure types, traits, and logic. Opt into a runtime via feature flags.
3. No default TLS — plain HTTP works out of the box. Enable rustls for HTTPS.
4. Runtime-agnostic core — HttpEngineSend<R, C> and HttpEngineLocal<R, C> are generic over runtime and connector traits. All pool, TLS, and HTTP logic works with any conforming runtime.
5. HTTP/3 as experimental — h3 + h3-quinn behind a feature flag.

Comparison with reqwest