Disk Cleanup

Disk Cleanup (macOS)

Free up disk space in three phases — Identify → Propose → Execute — without losing anything that matters. The whole point of this skill is to be aggressive about regenerable junk and careful about real data. Never delete in bulk; categorize first, confirm anything that isn't pure cache, and finish by realizing the space (snapshots — see Phase 3).

Scopes

$ARGUMENTS selects what to clean. With no argument, run the full all flow. If the argument is help, list, scopes, ?, or --help, print this table and stop — do not scan:

For a named scope, run the identify pass for just that area, then propose and execute scoped to it. For an unrecognized argument, show this table and ask which they meant rather than guessing.

Principles (internalize these — they prevent the two classic failures)

1. Measure real free space, not df /. / is the sealed read-only system volume and always looks ~full/empty. The number that matters is the Data volume: df -h /System/Volumes/Data.
2. Time Machine local snapshots hide reclaimed space. When you delete files that exist in a local snapshot, macOS keeps the bytes until the snapshot is purged. So you can delete 100 GB and watch free space not move — or even drop, if something else downloaded in the meantime. Always thin snapshots LAST (scripts/thin-snapshots.sh) and re-measure. This is usually the single biggest win.
3. Look before you delete. Inspect a target before removing it. If what you find contradicts how it was described — "leftover Parallels folder" turns out to be a 36 GB Windows VM with the user's files inside — stop and surface it instead of proceeding. You didn't create it; treat it as theirs.
4. Tier everything by safety, and confirm anything above tier 1 (see Phase 2). Pure regenerable cache can go freely. Data is irreversible — get explicit buy-in.
5. Prefer tool-native cleaners over rm. brew cleanup, docker system prune, npm cache clean, uv cache clean, xcrun simctl delete, ollama rm — they remove the right things and keep their own bookkeeping consistent. Raw rm is the fallback, not the default.
6. Report honestly. Show before/after free space. If space didn't move, investigate (snapshots? a background download?) rather than claiming success.

Phase 1 — Identify (read-only)

Run the scan scripts. They make no changes.

bash scripts/scan.sh                  # real free space, snapshot count, home + known targets, big apps
bash scripts/find-orphan-app-data.sh  # ~/Library data for apps that are no longer installed

Then drill into whatever's big and ambiguous with du -shx <dir> / du -hx -d 1 <dir> | sort -rh. For multi-GB items you don't recognize, look inside before proposing deletion (principle 3).

Reach for references/cleanup-targets.md — a catalog of every common target with its location, safety tier, the exact cleaner command, and what re-downloading/rebuilding costs. Use it to interpret the scan and to copy the right command in Phase 3.

Phase 2 — Propose (categorize, then ask)

Group findings into safety tiers and present a compact table (size · what it is · tier · recovery cost).

• Tier 1 — Safe / regenerable. Caches, build artifacts, package-manager downloads, old tool versions, dangling Docker images/build cache, stale snapshots. Delete freely; you may batch these.
• Tier 2 — Confirm: recreatable but costly or opinionated. Whole SDKs, all simulators/AVDs, Docker volumes (dev databases), Ollama models, full app uninstalls. Recreatable, but the user should choose scope. Use AskUserQuestion with clear options (orphaned-only / latest-kept / everything).
• Tier 3 — Data: never delete without explicit, specific confirmation. VMs (Parallels/VirtualBox) whose disk may hold files, crypto-wallet data, messaging history (Signal/WhatsApp), Postman collections, screenshots/recordings, user media, anything irreplaceable. Surface what's inside; if in doubt, recommend keeping.

Rules for proposing:

• Never bulk-delete Tier 2/3. One confirmation per meaningful decision.
• For version stacks, keep the current + latest and respect project pins. Before pruning Node versions check .nvmrc files; before pruning NDK/build-tools check what projects pin; keep the default and the newest of each major line.
• Cross-reference orphans against reality. A folder named like an app you removed is a candidate, but verify with mdfind -name "<App>.app" before deleting — names don't always map cleanly.
• Lead with the biggest safe wins. Call out the snapshot situation up front if free space looks tight.

Phase 3 — Execute (tool-native, confirm-gated, then realize the space)

Run the approved deletions, preferring the native cleaner for each target (full command list in references/cleanup-targets.md). A few that matter:

brew cleanup -s                                   # Homebrew downloads
npm cache clean --force && rm -rf ~/.npm/_npx     # npm cache + npx installs
uv cache clean; yarn cache clean                  # uv / Yarn
docker system prune -a -f && docker volume prune -a -f   # images+cache, THEN named volumes (Tier 2 — confirm)
xcrun simctl delete unavailable                   # simulators for runtimes you no longer have
xcrun simctl runtime delete <id>                  # old iOS runtimes (keep the current one)
ollama rm <model>                                 # specific local LLM models

Then the parts with walls and the finale:

• Version stacks (Node, JetBrains per-version config, NDK, iOS runtimes): delete all but the current + latest you confirmed keeping.

• Permission walls — explain and hand off rather than fight them:

  • Root-owned apps in /Applications → the user runs sudo rm -rf "/Applications/<App>.app" (suggest they paste it with a leading ! so it runs in-session).
  • ~/Library/Containers/* are TCC-protected → even sudo fails without Full Disk Access on the terminal. Offer Finder (drag to Trash — has the entitlement) or granting FDA then re-running (FDA only applies after the terminal is fully quit and reopened).

• THE FINALE — realize the space. After deletions, thin local snapshots and re-measure:

  bash scripts/thin-snapshots.sh
  

  Report before/after free space on the Data volume. If it didn't move as expected, investigate (lingering snapshots, a background download like a media/cloud sync) — don't claim a win you can't see.

For a complete, end-to-end app uninstall (e.g. Microsoft Office) including system daemons/helpers and the FDA-gated containers, see the "Full app uninstall" section of references/cleanup-targets.md.

Safety guardrails (always)

• Confirm before anything Tier 2/3. When unsure which tier, treat it as higher.
• Don't touch com.apple.* system folders, the Office shared containers while other MS apps remain, or ~/Library/Containers/com.microsoft.VSCode-style data for apps the user is keeping.
• Quote paths with spaces; on a no-match glob in zsh, run scripts via bash (the bundled scripts already do).
• Never propose disabling SIP or commit.gpgsign-style settings to "make deletion easier."