radiator-engineering/offcut/tree/main/mod
offcut
Cleans up finished git worktrees as soon as a turn or a session ends. When a turn ends, it runs `offcut apply --only auto --yes` for the session's repo in the background: a worktree goes only if it is clean, pushed, and its work is merged or eventlog says its agent is done. When the session ends, it runs once more a few seconds later, also clearing unused build caches.
About this mod
A Claude Code mod that finds and safely removes git worktrees and build output left behind by agents and builds. Worktrees are removed only when clean, pushed, unlocked, unused, and either merged or confirmed done by a provider; every removal is recorded for offcut restore. Installed via offcut mod install, it runs in the background at each turn or session end, clearing finished worktrees and, on broader runs, unused build caches (Cargo targets, uv virtualenvs, Bazel output bases). Requires Claude Code 2.1.278+ with CLAUDE_CODE_ENABLE_FUNCTION_HOOKS=1; can be disabled per session with OFFCUT=off.
Installation
Check the author's README for the marketplace and plugin name first. Commands may change as the repository evolves.
claude plugin marketplace add radiator-engineering/offcut claude plugin install offcut
Original text / README
offcut
Find and safely remove the git worktrees that agents and builds leave behind.
Agents create a worktree per task and rarely remove it. Each one can hold
gigabytes of build output. offcut lists them, says which are safe to remove,
and removes them only when you ask. Every removal is recorded, so you can undo it.
It works with git alone. It works better with an eventlog, which knows which worktrees belong to finished work.
Install
cargo install --git ssh://[email protected]/radiator-engineering/offcut
Use
Run it inside the repo you want to tidy. It finds that repo's worktrees
wherever they live (.worktrees/, .claude/worktrees/, a sibling folder).
offcut # same as `offcut report`; deletes nothing
offcut apply # show the plan, ask, then remove
offcut restore # list what `apply` removed
offcut restore <path> # put one back
offcut --caches report # also list unused build caches (Bazel output bases)
offcut mod install # clean up when each Claude Code turn or session ends
| Flag | Meaning |
|---|---|
| --root <dir> | Scan the repos under a folder instead. Repeatable. |
| --all | Scan everything under ~/Development, and the build caches. |
| --caches | Also look at build caches. Works outside a repo. |
| apply --only worktrees\|caches | Remove only one kind of item. |
| --max-age <days> | Idle days before a clean, pushed worktree goes. Default 30. |
| --sizes | Measure every worktree, not only the removable ones. Slower. |
| --json | Print JSON. |
| apply --yes | Skip the confirmation. |
| apply --detach | Run in the background and return at once. Needs --yes. |
| apply --delay <secs> | Wait before looking. |
What it will and won't remove
It never removes a worktree that:
- has uncommitted or untracked changes,
- has commits that no remote branch contains,
- is locked,
- has a process with a file open in it (unless every such process is an orphan working in it and a provider says done; see below), or
- a provider says to hold.
It removes a worktree that passes all of those and is either merged into the
default branch, or idle for --max-age days. "Merged" needs a commit, rebase or
merge made in the worktree. A new worktree has none, and its tip is already in
the default branch, so without that check it would count as finished the moment
it was made. It runs git worktree remove
without --force, and it does not delete branches.
Files that git ignores (build output, dependencies, .env) are not in git.
They are gone after a removal, and restore cannot bring them back.
Orphaned processes
Agents start dev servers and leave them running. Their parent exits, launchd
adopts them (parent pid 1), and they hold the worktree open forever. When a
provider says a worktree is done and every process holding it is such an
orphan, with its working directory inside the worktree, apply stops those
processes (SIGTERM, then SIGKILL after 5 s) and removes the worktree. A
process with a live parent, or one working elsewhere, still protects it.
Build output in worktrees
A worktree that stays can still hold gigabytes of build output. With
--caches or --all, offcut finds folders holding a CACHEDIR.TAG (Cargo's
target/, Python tool caches, uv virtualenvs) up to three levels into each
kept worktree, and removes one when nothing has it open and it has not
changed for 2 days. Removing one costs a rebuild, never work.
Build caches
Bazel keeps one output base per workspace under /private/var/tmp/_bazel_<user>/.
They grow without limit. offcut lists each one and removes it when no process
has a file open in it (a running Bazel server holds files open) and nothing in
it has changed for 7 days. A base whose workspace folder is gone (its worktree was
removed) goes as soon as nothing has it open. Caches rebuild, so removal is not recorded.
To manage other cache folders, add them to ~/.config/offcut/config.toml.
A path ending in /* means each folder inside it. This replaces the Bazel rule:
[[cache]]
path = "/private/var/tmp/_bazel_me/*"
max_age_days = 7
[[cache]]
path = "~/Library/Caches/some-tool"
max_age_days = 30
Cleaning up as you go
offcut mod install # writes ~/.claude/skills/offcut
offcut mod remove
This installs a Claude Code mod. When a turn ends, the main agent's or a subagent's, it runs this in the background, in the repo the session works in:
offcut apply --only auto --yes --detach
At most every 10 minutes a turn's run adds --all: every repo under
~/Development, plus build caches and build output. When the session ends, it
runs the same with --all --delay 5, so the
session's own worktree is no longer in use when offcut looks.
--only auto removes two kinds of thing:
- unused build caches, and
- finished worktrees: ones with commits in them that are now merged, or that a
provider says are done. Each removal is recorded, so
offcut restoreundoes it.
A worktree that is only idle is left for you. Run offcut, read the list, then
offcut apply.
Runs never make a turn wait. Each one writes to
~/.local/state/offcut/apply.log. Only one apply runs at a time; another
waits up to 60 s, then skips. Set OFFCUT=off to turn the mod off for one
session. The mod needs Claude Code 2.1.278 or later with
CLAUDE_CODE_ENABLE_FUNCTION_HOOKS=1.
Providers
A provider is a command that tells offcut what it knows about paths. It reads
absolute paths on stdin and prints one JSON line per path it has an opinion on:
{"path": "/abs/path", "verdict": "hold", "reason": "agent api has an open claim"}
hold protects a path. done says its owner has finished, which skips the idle
wait; the safety rules above still apply. A provider that fails or times out
holds every path.
Configure one in .offcut.toml in the repo, or ~/.config/offcut/config.toml:
[[provider]]
command = "eventlog worktree-facts --json"
If the repo has an event log and eventlog is on PATH, offcut uses that
provider with no config.
See docs/design.md for the design and what is not built yet.
