How do I install the Harness Gc skill?

Run npx skillmds@latest add first-fluke/harness-gc in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Harness Gc safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Harness Gc?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Harness Gc free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Harness Gc?

first-fluke (@first-fluke) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Harness Gc by first-fluke — Agent Skill

Name: Harness Gc
Author: first-fluke

File contents

Harness GC

When to use

User asks to run GC, garbage collection, or cleanup
Stale worktrees or branches are accumulating
Routine maintenance after a batch of issues have been completed and merged

When NOT to use

Implementing features or components — this skill only performs cleanup
Checking SPEC conformance -> use Symphony Conformance skill

Safety rules

Always run dry-run first. Never delete without showing the user what will be removed.
Never delete the main or master branch.
Never delete a worktree whose branch has an open PR.
GC follows soft-delete: flag first, delete on the next confirmed cycle. Unreferenced utilities are never auto-deleted — flag them and ask the user.

Steps

1. Show current stale worktrees (dry run)

Run the GC script in dry-run mode to list what would be cleaned without making any changes:

./scripts/harness/gc.sh --dry-run

If the script does not support --dry-run, manually inspect and list:

Worktrees whose associated PR has been merged
Branches with no commits in the last 30 days
Worktrees in done or failed status beyond config.workspace.retentionDays

Show the user the full list before proceeding.

2. Ask confirmation before deleting

Present the dry-run output to the user and ask:

The following worktrees and branches will be removed. Confirm to proceed? (yes / no)

Do not proceed if the user does not confirm. If the user says no, stop and report that no changes were made.

3. Run gc.sh

After confirmation, run the GC script:

./scripts/harness/gc.sh

GC targets per docs/harness/ENTROPY.md:

Target	Criteria	Action
Completed worktrees	PR merged, worktree still present	`git worktree remove`
Stale branches	Last commit > 30 days ago	`git branch -d` (local and remote)
Unreferenced utilities	No import references + > 30 days old	Flag only — do not delete, ask user

4. Report what was cleaned

After the script completes, report:

Harness GC Complete
===================
Worktrees removed: N
  - symphony/ACR-42
  - symphony/ACR-55

Branches deleted: N
  - symphony/ACR-42 (local + remote)
  - symphony/ACR-55 (local)

Flagged for review (not deleted):
  - src/utils/legacyParser.ts — no import references since 2024-02-01

Nothing else was changed.

If the script produced errors, report them with the full error message and suggested remediation.

References

scripts/harness/gc.sh — GC script
docs/harness/ENTROPY.md — GC targets, soft-delete policy, run schedule
docs/harness/LEGIBILITY.md — worktree lifecycle
docs/specs/workspace-manager.md — retention policy (config.workspace.retentionDays)
.github/workflows/harness-gc.yml — automated weekly GC workflow

---name: harness-gcdescription: Runs the harness garbage collection to clean up stale worktrees and branches. Use when user asks to "run gc", "clean up worktrees", "harness cleanup", or "gc".---# Harness GC## When to use- User asks to run GC, garbage collection, or cleanup- Stale worktrees or branches are accumulating- Routine maintenance after a batch of issues have been completed and merged## When NOT to use- Implementing features or components — this skill only performs cleanup- Checking SPEC conformance -> use Symphony Conformance skill## Safety rules- Always run dry-run first. Never delete without showing the user what will be removed.- Never delete the `main` or `master` branch.- Never delete a worktree whose branch has an open PR.- GC follows soft-delete: flag first, delete on the next confirmed cycle. Unreferenced utilities are never auto-deleted — flag them and ask the user.## Steps### 1. Show current stale worktrees (dry run)Run the GC script in dry-run mode to list what would be cleaned without making any changes:```bash./scripts/harness/gc.sh --dry-run```If the script does not support `--dry-run`, manually inspect and list:- Worktrees whose associated PR has been merged- Branches with no commits in the last 30 days- Worktrees in `done` or `failed` status beyond `config.workspace.retentionDays`Show the user the full list before proceeding.### 2. Ask confirmation before deletingPresent the dry-run output to the user and ask:> The following worktrees and branches will be removed. Confirm to proceed? (yes / no)Do not proceed if the user does not confirm. If the user says no, stop and report that no changes were made.### 3. Run gc.shAfter confirmation, run the GC script:```bash./scripts/harness/gc.sh```GC targets per `docs/harness/ENTROPY.md`:| Target | Criteria | Action ||---|---|---|| Completed worktrees | PR merged, worktree still present | `git worktree remove` || Stale branches | Last commit > 30 days ago | `git branch -d` (local and remote) || Unreferenced utilities | No import references + > 30 days old | Flag only — do not delete, ask user |### 4. Report what was cleanedAfter the script completes, report:```Harness GC Complete===================Worktrees removed: N - symphony/ACR-42 - symphony/ACR-55Branches deleted: N - symphony/ACR-42 (local + remote) - symphony/ACR-55 (local)Flagged for review (not deleted): - src/utils/legacyParser.ts — no import references since 2024-02-01Nothing else was changed.```If the script produced errors, report them with the full error message and suggested remediation.## References- `scripts/harness/gc.sh` — GC script- `docs/harness/ENTROPY.md` — GC targets, soft-delete policy, run schedule- `docs/harness/LEGIBILITY.md` — worktree lifecycle- `docs/specs/workspace-manager.md` — retention policy (`config.workspace.retentionDays`)- `.github/workflows/harness-gc.yml` — automated weekly GC workflow

Frequently asked questions

Harness Gc