Graft

Copy-on-write workspaces for parallel coding agents: a permanent replacement for git worktree.

Every agent gets a graft: a copy-on-write view of one shared Root plus a private delta that holds only what that agent changed. Creating, forking and pruning a graft is meant to take about a second regardless of repo size. On top of that, Graft gives each graft its own runtime (ports, databases, .env), detects overlapping edits between agents while they work, and lands finished work into Root through a tested merge queue. The output is always ordinary git history.

Status: early development. Grafts are real working trees whose unchanged files are reflinks of Root's; virtual (lazy) grafts come later. See docs/STATUS.md for progress and docs/architecture.md for the design.

Try it

cargo install --path crates/graft-cli   # installs `graft`
graft doctor              # can this machine reflink?
graft init                # register this repository as a Root
graft new auth            # a graft checked out at HEAD
cd "$(graft path auth)"   # work in it like any git checkout
graft ls                  # name, base, state, changed files, unshared disk
graft status auth         # what changed since the base
graft diff auth           # as a unified diff
graft prune auth          # refuses if work would be lost; --force to discard

Dependency trees are built once and shared: declare them as layers in graft.toml (reference), approve the build command once with graft trust, and every graft after the first gets node_modules (or target/) as a reflink in milliseconds. graft gc removes layers no graft uses.

graft doctor reports the platform, the filesystem the repository is on, whether it supports reflinks (tested by cloning a scratch file), where $GRAFT_HOME is, and whether FUSE and NFS are available.

Development

The toolchain is pinned in rust-toolchain.toml.

cargo fmt --all --check
cargo clippy --workspace --all-targets --all-features -- -D warnings
cargo test --workspace
cargo deny check

Tests never touch your real $GRAFT_HOME. The privileged filesystem tests (loop-mounted ext4, btrfs and XFS) run in CI; see crates/graft-fs/tests/privileged.rs to run them locally on Linux.

Contributors, human or agent, start with AGENTS.md.

License

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