created_at2021-07-08 16:48:09.930084
updated_at2024-04-13 11:56:15.898151
descriptionasync HTTP(S) client



Project Status: Active – The project has reached a stable, usable state and is being actively developed. Released API docs MIT licensed

A generic async HTTP request create.

It is meant to be a thin wrapper around various HTTP clients and handles TLS, serialization and parsing.

The main goal is to allow binaries (that pull in some libraries that make use of a HTTP client) to specify what implementation should be used.

And if there is a Proxy. If not specified auto detection is performed by looking at HTTP_PROXY.


You need to specify via features what crates are used to do the actual work.

feature flag Meaning
use_hyper Use hyper for HTTP GitHub Workflow Status
use_async_h1 Use async_h1 for HTTP GitHub Workflow Status
rustls Add support for HTTPS via rustls
proxies Add support for Socks5 and HTTP proxy
hyper_native_tls Use hyper for HTTP and do HTTPS via native_tls GitHub Workflow Status
async_native_tls Use async_h1 for HTTP and do HTTPS via native_tls GitHub Workflow Status

Without anything specified you will end up with No HTTP backend was selected. If you use this crate for a library, please reexport the appropriate features.


Rust offers different async runtimes that - on a high level - offer the same thing: asynchronous functions for files, sockets and so on.

So if you write a lib and need some basic stuff (like an http client) you sometimes have to make choices that are not what your crates users would have liked. For example: I wrote a webserver based on hyper and wanted to add ACME. A crate I found did what I needed but used async-h1 and async-std. While that worked, it did increase the binary size and crates I depend on by a good amount.

So I wrote this. You can specify which backend to use. In the Webserver case, using tokio which is already a dependency VS async-std did lead to 81 less crates and a 350kB smaller binary. Using (and async-acme):

lto = "fat"
codegen-units = 1

Also for http clients: there should be a way to add a proxy for all libs that use it.


  1. Add Sessions - to make multiple requests more efficient
  2. Add a cookie jar for the sessions
  3. Allow a Body to be streamed from a server
  4. Allow a Body to be streamed to a server
Commit count: 37

cargo fmt