zit

A Fossil version-control system implemented in Zig — a direct port of the Fossil formats and protocol from their specifications.

zit is driven by four companion Internet-Drafts (the frozen reference finals are in docs/rfcs/):

Module	RFC	What it specifies
delta	draft-fossil-delta-format-00	byte-level delta encoding
artifact	draft-fossil-artifact-format-00	manifest / control-artifact card format, naming, checksums
repostate	draft-fossil-repo-state-00	derived branch / tag / leaf / current-trunk views
sync	draft-fossil-sync-protocol-00	HTTP sync / clone protocol

Implementation follows the RFC dependency layering:

delta  ->  artifact  ->  repostate  ->  sync

Scope

zit targets the version-control substrate: the check-in (manifest), cluster, and tag/control artifact types. The collaboration types (wiki, ticket, forum, attachment, technote) are carried opaquely — stored and transported by hash, but not interpreted.

Build

Requires Zig 0.16+.

zig build            # build the `zit` binary into zig-out/bin/
zig build run -- version
zig build test       # run unit tests

Status

Scaffold. Implemented so far:

• delta: base-64 integer codec (MSB-first) and the checksum (mod 2³²), each with RFC-derived test vectors.
• artifact: artifact naming (SHA-1 / SHA3-256, lowercase hex) and the Z-card MD5, with the RFC's own example vectors as tests.

Everything else is stubbed against its RFC section. Work proceeds test-first, one RFC rule at a time, verifying against the reference implementation (fossil 2.28) where a byte-exact check is possible.

Source control

This project is itself under Fossil. The repository lives in .zit.fossil (ignored); open a checkout with fossil open --keep .zit.fossil.