Zit is a git extension for repositories that several developers and coding agents change at once. Start an agent on a bug, another on a feature, a third on the docs, while your teammates do the same. Zit gives each session a copy-on-write copy of the code instead of a worktree, lets the sessions see and claim what the others are changing, and lands their work one change at a time, each checked against what landed meanwhile. Every change keeps its author's account of what was done and why.

Your branches, history and remotes stay plain git. Teammates who never install Zit are not affected.

_{A real, unedited run at 6× speed: Autohand Code, Claude Code and Codex change one repository at once; all three changes land, with the link check passing on each combined state.}

Get started

cargo install zit --locked     # installs zit and git-zit; needs git 2.38+, macOS or Linux
git zit doctor                 # git version, copy-on-write, free space, agents on PATH
cd your-repo && git zit init   # refs/zit/current = HEAD; nothing else changes

git zit run --agent autohand --intent "Add a discount function to src/lib.rs" &
git zit run --agent claude   --intent "Add tests for the discount function" &
git zit run --agent codex    --intent "Document discounts in README.md" &
git zit run --agent pi       --intent "Add a --discount flag to the CLI" &
wait

git zit status                 # every change and workspace, and why a change cannot land
git zit show <change>          # what it wrote, its author's reason, what it cost
git zit web                    # watch it live in the browser
git zit accept <change>        # land it, or get the reason it cannot land
git zit accept --batch         # or land every verified change at once, checked once
git zit log                    # what landed, by whom, and what it cost
git zit export --branch main   # publish to git (or --branch zit/ready --pr for a pull request)

Why Zit

Workspaces that don't copy your repository. Each session gets a copy-on-write clone of a cached checkout: files are shared on disk until one is edited. Ten workspaces of a 30,000-file repository take 98 MB with Zit against 1,390 MB with worktrees. With [prepare], installed dependencies are shared too: five contributors on a project with 206 MB of npm dependencies used 327 MB instead of 1,619 MB.

Agents that split the work instead of colliding. Sessions on one machine see what the others are writing, and claim a file, a function or a Markdown section before starting (zit claim src/lib.rs#price). Five Claude Code agents given the same task landed 10 of 10 changes with claims and 4 of 10 without, at $1.01 against $2.54 per landed change.

Merges git can't judge, caught before they land. A change that calls a function whose signature changed underneath it is refused even though git would merge it. Footprints are at symbol level for Rust, Python, JavaScript, TypeScript, Go, Java, Ruby and C#, by section in Markdown, and by table or key in TOML and JSON manifests. Then the combined result must parse and pass your checks, and the change's own, before refs/zit/current moves.

The reason stays with the change. An agent's final message becomes the commit body, and the tokens and dollars it reported become commit trailers, so git log keeps them.

Fits the team rules you have. Linear history, signed commits, your identity as committer, and zit export --pr so protected branches and merge queues apply as usual.

Works with your agents

Honest numbers

Measured on one machine, in one or two runs each. Zit is not faster than worktrees at integrating; what it saves is disk, duplicated work and broken merges. How each number was produced, and what is not measured, is in Benchmarks, Lessons and Limits.

Requirements

• git 2.38 or newer. Zit uses git merge-tree --write-tree; it checks the version and names the one it needs.
• macOS or Linux. Windows is not supported yet.
• A copy-on-write file system for the disk savings: APFS on macOS, btrfs or XFS with reflink on Linux, all tested in CI. On other file systems a workspace is a plain checkout.
• To build from source: Rust 1.88 or newer.

Install

cargo install zit --locked

Or take a prebuilt binary for macOS (arm64, x86_64) or Linux (x86_64, arm64) from Releases, each with a SHA-256 checksum, or build from a checkout with cargo install --path . --locked.

Documentation

Everything is at getzit.org: start with Zit 101, see how it compares to merge queues, worktrees, Zed's Delta and Entire in Compared, and what it does not do in Limits. The site is built with Blume from docs/ (npm install && npm run dev). Design decisions are in adr/ and real-world findings in lessons_learnt/. Library documentation: cargo doc --open.

Contributing

Issues, ideas and pull requests are welcome. CONTRIBUTING.md covers setting up, testing (cargo test runs against real git repositories), the Signed-off-by line every commit needs, and how releases are made. Please read the code of conduct, and report security issues privately as described in SECURITY.md.

License

Zit is licensed under the GNU General Public License, version 2 only (GPL-2.0-only), the same license as git. See LICENSE. The Autohand Sans and Autohand Mono fonts embedded in the web view are under the SIL Open Font License 1.1 (src/web/fonts/OFL.txt).