dev-disk-doctor

Why is my disk full? A read-only disk and git-worktree doctor for developer machines. It finds the space hogs (Docker, Android emulators, Xcode, node_modules, package caches, AI models, orphaned git worktrees), explains each one, and gives you a ready-to-run fix with a warning when one is needed.

Works as a CLI and as an MCP server, so an AI agent (Claude Code, Cursor, Codex…) can run it, show you the options, and ask before touching anything.

npx dev-disk-doctor            # scan, read-only
npx dev-disk-doctor worktrees  # how many git worktrees do I have, and which are leftovers?

Getting started

You need Node.js 18 or newer. Nothing else to install.

1. Scan (read-only, about a minute on a big disk):

   npx dev-disk-doctor

   You get a ranked list. Each item says what it is, how big it is, how risky deleting it is, and the exact command to fix it.
2. Check the git worktrees (also read-only):

   npx dev-disk-doctor worktrees

3. Fix one item at a time. Copy the id: shown under an action. This shows what would happen and changes nothing:

   npx dev-disk-doctor fix "docker:build-cache#prune"

   Add --yes to actually run it.
4. Or let an AI agent drive it; see Use it with an AI agent below.

To install it globally instead of using npx: npm install -g dev-disk-doctor, then run dev-disk-doctor.

Where it looks for your projects

Projects, node_modules and git worktrees are searched in your workspace folders. You don't have to configure them:

• Common names directly under your home folder are always used if they exist: dev, code, src, projects, work, workspace, workspaces, Developer, repos, git, Sites.
• Any other visible folder directly under your home that contains a git repo or project within three levels is picked up too. So a company folder such as ~/acme is found automatically, even though it has an arbitrary name.
• Also checked automatically, for worktrees: the places AI coding tools park them (~/.codex/worktrees, ~/.cursor/worktrees, ~/.claude/worktrees, ~/conductor), and .claude/worktrees inside any repo.
• Never searched by default: ~/Documents, ~/Desktop, ~/Downloads, ~/Library, ~/Applications, hidden folders, and cloud-sync folders (Dropbox, OneDrive, Google Drive, iCloud…), because they are slow and can trigger permission prompts.

See what it will use:

npx dev-disk-doctor roots

Override it when your code lives somewhere else (for example ~/Documents/GitHub or an external drive):

npx dev-disk-doctor --root ~/Documents/GitHub --root /Volumes/Work/code
# or, for every run:
export DEV_DISK_DOCTOR_ROOTS="$HOME/Documents/GitHub:/Volumes/Work/code"

When you pass --root or set DEV_DISK_DOCTOR_ROOTS, auto-discovery is turned off and only those folders are searched.

What it checks

Area	Examples
Containers	Docker Desktop disk image (Docker.raw), unused images, build cache, stopped containers, volumes
Mobile	Android emulator system images (never one an AVD uses), AVD data, NDKs, Xcode DerivedData, DeviceSupport, simulators
Package caches	npm, pnpm (old store versions too), Yarn, Bun, pip, uv, conda, Homebrew, Cargo, Gradle, Maven, CocoaPods, Go
Test browsers	Playwright, Puppeteer, Cypress downloads
AI models	Hugging Face, Ollama, LM Studio, PyTorch hub, DiffusionBee
Projects	node_modules, .next, Rust target/, Pods/, Python venvs in your workspaces, with how long the project has been idle
Git worktrees	Every linked worktree in every repo under your workspaces, including those made by Claude Code, Codex, Cursor and Conductor: active, stale, dangling, locked, at-risk, or orphaned
System	Trash, big Downloads, logs, iOS backups, Time Machine local snapshots
Everything else	--deep sweeps your home folder for hogs nobody else recognises

Safe by design

• Scanning never changes anything. No network, no telemetry.
• Every finding has a risk level: SAFE (regenerates on its own), REVIEW (probably fine, check first) or CAREFUL (could lose data, never run by the tool).
• fix <action-id> is a dry run unless you add --yes. Actions come from a fixed allowlist built by the scanners; the tool never executes free-form commands.
• Worktrees are offered for removal only when they are clean, unlocked, and merged or fully pushed. Dirty worktrees, unpushed commits and Docker volumes are reported with a warning and no apply path.
• It will not delete anything outside your home folder, your home folder itself, or Documents, Desktop, Library and other top-level folders.

Use it with an AI agent (MCP)

Add to your MCP client config:

{
  "mcpServers": {
    "dev-disk-doctor": { "command": "npx", "args": ["-y", "dev-disk-doctor", "mcp"] }
  }
}

Claude Code: claude mcp add dev-disk-doctor -- npx -y dev-disk-doctor mcp

Tool	What it does
disk_scan	Ranked findings with explanations, risk and available actions
worktree_audit	All repos, all worktrees, which are stale, dangling, orphaned or at risk
explain_finding	Re-checks one finding
apply_action	Runs one allowlisted action. Dry run unless confirm: true. Refuses anything risky

No MCP? Give your agent the playbook in skills/dev-disk-doctor/SKILL.md and it can drive the CLI with --json.

CLI

dev-disk-doctor [scan]            Scan for space hogs (read-only)
dev-disk-doctor worktrees         Audit git worktrees across all your repos
dev-disk-doctor fix <action-id>   Show what an action does; add --yes to run it
dev-disk-doctor roots             Show which workspace folders will be searched
dev-disk-doctor mcp               Start the MCP server on stdio

--json  --root <dir>  --min-size <MB>  --stale-days <n>  --only <detector>  --deep  --all  --yes

Why does macOS say "Documents" is 230 GB?

macOS Storage settings has a category called Documents that is not your ~/Documents folder. It is everything macOS cannot file under Apps, Photos, Mail or System, which for a developer means ~/Library (Docker's disk image, Android SDK images, app data), ~/.cache, ~/.npm, model downloads and your code. Run npx dev-disk-doctor to see what is actually in there.

Common questions

• How do I shrink Docker.raw? Prune inside Docker (docker image prune -a, docker builder prune -a), then compact the disk image in Docker Desktop → Settings → Resources. The tool reports what is reclaimable and warns about volumes.
• How do I delete old Android system images? The scan lists every image under ~/Library/Android/sdk/system-images, marks the ones your emulators use, and gives a removal command for the rest.
• How do I find stale git worktrees? npx dev-disk-doctor worktrees lists every linked worktree across your repos with its state and size. AI coding tools create many; some get orphaned.
• Is the pnpm store safe to delete? It is a cache. Old store versions (v3, v10) that your installed pnpm does not use can go; the active one is pruned rather than deleted.

Platform support

macOS is the primary target and is tested. Linux works for the cross-platform checks (Docker, package caches, models, projects, worktrees). Windows is not supported yet.

Development

npm install
npm test        # builds, then runs the node:test suite
npm run scan    # build and run against your machine

The scanner core is in src/core, one file per area in src/detectors, the worktree audit in src/worktrees, and the MCP server in src/mcp.ts. See PLAN.md for the design.

Releasing (maintainers)

Pushing a v* tag publishes to npm through GitHub Actions. Setup, the release steps, how to verify a release and troubleshooting are in docs/RELEASING.md.

License

MIT