Blaze

C++20 HTTP client. Built on libcurl. Coroutines for async, curl_multi for the event loop, no threads-per-request nonsense.

Why

Every C++ HTTP library is either a thin curl wrapper with no async story, or a Boost.Beast-level commitment. Blaze sits in between: real non-blocking I/O through curl_multi, exposed as C++20 coroutines (co_await), with a sync API when you don't need that. One header, one library, link against curl.

How it works

Sync requests go through curl_easy_perform with connection pooling. Async requests submit to a process-global curl_multi event loop on a background thread. Each async_* call returns a Task<HttpResponse> you co_await. when_all runs multiple requests concurrently through the same multi handle. async_race returns the first to complete and cancels the rest.

Build

cmake -B build
cmake --build build
cd build && ctest --output-on-failure
cmake --install build --prefix /usr/local

Needs C++20 (GCC 11+, Clang 14+, MSVC 19.29+), CMake 3.14+, libcurl.

Usage

#include <blaze/blaze.hpp>

blaze::HttpClient client;

auto r = client.get("https://api.example.com/data");

auto r = co_await client.async_get("https://api.example.com/data");

auto [r1, r2, r3] = co_await blaze::when_all(
    client.async_get("https://api.example.com/a"),
    client.async_get("https://api.example.com/b"),
    client.async_get("https://api.example.com/c")
);

auto [winner, response] = co_await client.async_race(std::move(requests));

blaze::sync_wait(someCoroutine());

Config, auth, SSL, retry, interceptors, HTTP/2/3, proxy, streaming, file upload/download — all there. Look at lib/http_client.hpp for the full API.

License

Apache 2.0