zhttp3

HTTP/3 framing, QPACK header compression, and an opinionated server layer, built on zquic.

Status: pre-release / active development. Phases 1–5 complete. Not ready for production use.

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Overview

zhttp3 implements the application layer of the HTTP/3 stack:

┌──────────────────────────────────────────────────────┐
│  src/server/   Handler(Request, Response)            │  ← protocol-agnostic
│                comptime router, middleware, C API    │
├──────────────────────────────────────────────────────┤
│  src/http3/    HTTP/3 framing          RFC 9114      │  ← translates between
│  src/qpack/    QPACK                   RFC 9204      │    wire and HTTP types
├──────────────────────────────────────────────────────┤
│  zquic         QUIC transport          RFC 9000      │  ← separate library
└──────────────────────────────────────────────────────┘

Handlers are protocol-agnostic — they only see Request and Response. No frame types, stream IDs, or QPACK state ever reaches handler code.

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Goals

• RFC-correct QPACK (RFC 9204) and HTTP/3 (RFC 9114) implementation in pure Zig
• Zero allocation in the hot path (pre-allocated buffers throughout)
• Comptime router with perfect hash — no runtime dispatch
• Pluggable handler ABI: Zig native, C/C++/Rust via .so, or WASM via wasmtime
• Designed for modern hardware (AES-NI, io_uring) via the underlying zquic transport

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Usage

Zig

build.zig.zon:

.dependencies = .{
    .zhttp3 = .{
        .url = "https://github.com/ericsssan/zhttp3/archive/refs/tags/v0.1.0.tar.gz",
        .hash = "...",
    },
},

build.zig:

// Full server
exe.root_module.addImport("zhttp3", b.dependency("zhttp3", .{}).module("server"));

// HTTP/3 framing + QPACK only
exe.root_module.addImport("http3", b.dependency("zhttp3", .{}).module("http3"));

C / C++

# Build produces libzhttp3.a and libzhttp3.so
# Include: include/zhttp3.h
# Link: -lzhttp3 -lzquic

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Roadmap

Phase	Scope	Status
1	QPACK — static table, Huffman, integer/string encoding, encoder/decoder	✅ Done
2	HTTP/3 framing — DATA, HEADERS, SETTINGS, GOAWAY, control streams	✅ Done
3	Server layer — comptime router, handler interface, middleware	✅ Done
4	Server push + graceful shutdown — PUSH_PROMISE, push streams, GOAWAY state machine	✅ Done
5	Connection layer — QPACK + framing + server dispatch wired into a single Connection type	✅ Done

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Development

Requirements: Zig master (0.16.0-dev or later).

git clone https://github.com/ericsssan/zhttp3.git
cd zhttp3
zig build test

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Architecture

See DESIGN.md for the full design document.

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License

MIT — see LICENSE.