Add Understand-Anything

This skill installs Understand-Anything — an LLM-powered codebase-analysis tool that produces interactive knowledge graphs, guided tours, and deep-dive explanations of any project. Once installed, the agent gains the /understand* family of skills.

It ships as a Claude Code plugin distributed through a GitHub plugin marketplace. This skill runs the whole marketplace flow (add marketplace → install plugin → verify) end-to-end so a single /add-understand-anything completely integrates it — no manual /plugin steps.

Backend note: This is a Claude Code installer. The claude plugin … commands below only exist when Claude Code is the active backend (Deus's default). On non–Claude-Code backends (Codex, opencode, gemini, …) use the upstream install.sh fallback in Phase 0 instead.

Phase 0: Backend guard

Confirm the Claude Code CLI is available before doing anything else:

command -v claude >/dev/null 2>&1 && echo "claude CLI found" || echo "NO claude CLI"

If the claude CLI is not found, this backend can't use the plugin marketplace. Stop here and tell the user to install via the upstream script instead (it symlinks the skills into the right place for their runtime):

# Replace <platform> with one of: codex, opencode, gemini, pi, vscode, ...
curl -fsSL https://raw.githubusercontent.com/Lum1104/Understand-Anything/main/install.sh | bash -s <platform>

Then skip the rest of this skill.

Phase 1: Pre-flight (idempotent)

Check current state with the read-only list commands and branch on their output — do not assume how the CLI handles a duplicate add/install.

Is the marketplace already added?

claude plugin marketplace list 2>/dev/null | grep -qF "Lum1104/Understand-Anything" \
  && echo "MARKETPLACE_PRESENT" || echo "MARKETPLACE_MISSING"

(Match the exact marketplace source Lum1104/Understand-Anything — list prints it as Source: GitHub (Lum1104/Understand-Anything) — so an unrelated plugin that merely contains the substring understand-anything can't trigger a false MARKETPLACE_PRESENT.)

• MARKETPLACE_PRESENT → skip the marketplace-add step in Phase 2.
• MARKETPLACE_MISSING → run it.

Is the plugin already installed?

claude plugin list 2>/dev/null | grep -q "understand-anything@understand-anything" \
  && echo "PLUGIN_INSTALLED" || echo "PLUGIN_NOT_INSTALLED"

• PLUGIN_INSTALLED → tell the user it's already installed and skip straight to Phase 3: Verify.
• PLUGIN_NOT_INSTALLED → continue to Phase 2.

Phase 2: Install and configure

Run only the steps Phase 1 marked as needed. Check each command's exit status — a non-zero exit (network failure, marketplace fetch error, install error) is a failure: stop, show the CLI's error output to the user, and do NOT continue to Verify or claim success.

Add the marketplace (only if MARKETPLACE_MISSING)

claude plugin marketplace add Lum1104/Understand-Anything

Install the plugin (only if PLUGIN_NOT_INSTALLED)

Installed at user scope (the default) so it's available in every Claude Code session on this machine. The plugin reference is intentionally version-free so it always tracks the marketplace's current release.

claude plugin install understand-anything@understand-anything

Phase 3: Verify

Confirm the plugin is registered:

claude plugin list 2>&1 | grep "understand-anything@understand-anything" \
  && echo "OK: installed" || echo "FAILED: not found"

If this prints FAILED: not found, the install did not complete — surface the error from Phase 2, do not tell the user it's installed, and stop.

If verification passes (OK: installed), tell the user:

Understand-Anything is installed. Restart (or reload) your Claude Code session so the new skills load — plugins are read at session start.

Once reloaded you'll have:

• /understand — analyze a codebase into an interactive knowledge graph
• /understand-chat — ask questions about the codebase via the graph
• /understand-dashboard — launch the interactive web dashboard
• /understand-diff — analyze a git diff / PR (changes, affected components, risk)
• /understand-domain — extract business-domain knowledge and flow graph
• /understand-explain — deep-dive a specific file, function, or module
• /understand-knowledge — graph an LLM/wiki knowledge base
• /understand-onboard — generate an onboarding guide for new team members

Dashboard prerequisite: /understand-dashboard needs Node ≥ 22 and pnpm ≥ 10 — it builds its React dashboard lazily on first launch. The analysis skills (/understand, /understand-explain, etc.) work without it.

Removal

To remove Understand-Anything:

1. Uninstall the plugin:

   claude plugin uninstall understand-anything@understand-anything
   

2. (Optional) Remove the marketplace too — only if no other plugin from it is in use:

   claude plugin marketplace remove understand-anything
   

3. Restart the Claude Code session so the /understand* skills unload.