QAIL Zig Documentation

Zig-first PostgreSQL wire-protocol driver with AST-native query building, PostgreSQL-path parity tracking against qail.rs, and optional Linux Kerberos/GSSENC integration via the platform GSSAPI stack.

QAIL Zig is the active Zig implementation of the QAIL PostgreSQL stack. It shares the same AST direction as qail.rs, but keeps the runtime, protocol path, and tooling in Zig. The core driver path is Zig-native; Linux Kerberos/GSSENC support is an optional runtime integration with system libc/GSSAPI rather than a self-contained Zig Kerberos stack. Full qail.rs ecosystem parity is still incomplete outside the PostgreSQL-focused track.

Latest Updates (April 2026)

• qail-zig is active again and no longer documented as deferred.
• PG driver hardening now includes AST sanitization, stricter startup/auth sequencing, COPY fail-closed checks, and replication hardening suites.
• The current public benchmark story is now the dedicated qail-zig versus pg.zig shared-surface matrix.
• qail-zig now has its own versioned changelog and docs track.
• Real PostgreSQL CLI validation is now explicitly tracked for exec, seed, pull, and migrate status|plan|up|down paths.
• Migration receipt hardening now records full receipt fields and handles generated-version collisions for immediate back-to-back migration runs.
• Current repository snapshot: 52,795 tracked text lines total, including 50,049 lines of Zig across 169 tracked .zig files.
• The current qail.rs reference size for parity tracking is 209,728 total lines.

Repository Snapshot

• Total LOC: 52,795 tracked text lines in qail-zig.
• Zig LOC: 50,049 lines across 169 tracked .zig files.
• qail.rs total LOC: 209,728 lines.

.
├── src/                # Driver, AST, parser, protocol, runtime, CLI, tests, benches
├── scripts/            # Codegen, parity, and policy guards
├── docs/               # mdBook pages and theme overrides
├── .github/workflows/  # CI workflows
├── build.zig           # Build graph and targets
└── PARITY_AST_PG_DRIVER.md

What QAIL Zig Covers

Implementation Positioning

• qail.rs is still the production reference and widest implementation.
• qail-zig is the serious Zig track, with active parity work and dedicated benchmarks.
• Security boundary: on the AST flow, the goal remains no application SQL string interpolation surface.

Docs Map

• Start with Installation and Quick Start.
• Use PostgreSQL Driver for transport and feature coverage.
• Use Security Hardening for the recent fail-closed work.
• Use Throughput Benchmarks and qail.rs Parity Status to track the implementation line.