A QUIC protocol library for Zig. Sans-I/O — you own the socket; the library owns the state machine.
- QUIC v1 (RFC 9000) and v2 (RFC 9369)
- TLS 1.3 client and server handshake with AES-128-GCM and ChaCha20-Poly1305 (RFC 9001)
- Session resumption and 0-RTT
- Loss recovery, RTT estimation, PTO (RFC 9002)
- CUBIC and BBR v3 congestion control (RFC 9438)
- Stream multiplexing and flow control
- Path migration and NAT rebinding
- Pacing with wire-time accounting
- Packet coalescing (RFC 9000 §12.2)
- PMTUD, retry tokens, key rotation, ECN
- Ed25519 and P-256 certificates
- Zero external dependencies
zig build test # run tests (default: BBR)
zig build test -Dcongestion=cubic # run tests with CUBIC
zig build # build server binary
zig build -Dcongestion=cubic # build with CUBICRequires Zig 0.17.0-dev.657+2faf8debf or later.
Tested against 11 QUIC clients via quic-interop-runner on a 10 Mbps / 30 ms RTT link:
| Client | Tests | Goodput |
|---|---|---|
| ngtcp2 | 22/22 | 9432 kbps |
| quic-go | 20/20 | 9507 kbps |
| quiche | 18/18 | — |
| neqo | 19/22 | — |
| kwik | 19/21 | 7849 kbps |
| picoquic | 16/22 | — |
| mvfst | 12/16 | 9496 kbps |
| aioquic | 13/21 | 9190 kbps |
| lsquic | — | 9454 kbps |
| msquic | — | 7937 kbps |
| quinn | — | 9462 kbps |
Test cases: handshake, transfer, longrtt, chacha20, multiplexing, retry, resumption, zerortt, http3, blackhole, keyupdate, ecn, amplificationlimit, handshakeloss, transferloss, handshakecorruption, transfercorruption, v2, ipv6, rebind-port, rebind-addr, connectionmigration
Beyond the quic-interop-runner suite above, an in-tree oracle harness (oracle/run.sh) cross-checks zquic — as both server and client — against quic-go, ngtcp2, and quiche through a capturing proxy. Its server-direction loss cases run deterministically: transferloss (6% drop) and transfercorruption (2% bit-flip) pass reliably under a fixed seed, and oracle/run.sh -n N gates on N consecutive all-green runs.
- The interop matrix above is server-side; the client is implemented and verified against reference servers for core cases, but its coverage is narrower than the server's.
MIT