h2corn 1.4.3

High-performance HTTP/2 ASGI server

h2corn

High-performance HTTP/2 ASGI server for FastAPI, Starlette, and similar applications.
Documentation · Quickstart · Configuration · Benchmarks

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h2corn keeps application traffic on HTTP/2 end-to-end instead of downgrading to HTTP/1.1 inside your trust boundary. It is built around h2c behind a trusted reverse proxy, with optional direct TLS for TCP listeners.

• Better security for the proxy → application connection (no HTTP/1.1 downgrade)
• Higher throughput and lower latency from a Rust core on Tokio + Hyper
• Compatible with any ASGI 3 application — FastAPI, Starlette, Django, Litestar
• Direct TLS with Rustls and modern defaults
• RFC 8441 WebSockets over HTTP/2
• Operator-friendly: multi-worker supervisor with graceful shutdown, rolling reload, live scaling, worker recycling, and health checks

Install

uv add h2corn         # or: pip install h2corn

A 60-second start

# hello.py
from fastapi import FastAPI

app = FastAPI()


@app.get('/')
async def index():
    return {'message': 'hello from h2corn'}

h2corn hello:app

For production, put h2corn behind a reverse proxy that speaks h2c upstream (Caddy or HAProxy), then disable HTTP/1.1 with --no-http1. The full deployment recipes live in the docs.

Benchmarks

In local runs comparing h2corn, uvicorn, hypercorn, and gunicorn across baseline GETs, Unix sockets, static files, streaming, and WebSockets, h2corn leads on every scenario tested:

Full plots and methodology: Benchmarks.

Support

Bug reports, feature requests, and questions go in the GitHub issue tracker.

For deployment review, migration help, performance audits, or prioritized work, commercial support is available through monicz.dev. See the Support page for details.

Security disclosures: use GitHub's private vulnerability reporting.

License

MIT.