{"id":"understand-explain","name":"understand-explain","summary":"コードベースの特定のファイル、関数、モジュールについて深く説明したいときに使います","body":"# /understand-explain\n\nProvide a thorough, in-depth explanation of a specific code component.\n\n## Graph Structure Reference\n\nThe knowledge graph JSON has this structure:\n- `project` — {name, description, languages, frameworks, analyzedAt, gitCommitHash}\n- `nodes[]` — each has {id, type, name, filePath?, summary, tags[], complexity, languageNotes?}\n  - Code node types: file, function, class, module, concept\n  - Non-code node types: config, document, service, table, endpoint, pipeline, schema, resource\n  - Domain/knowledge node types: domain, flow, step, article, entity, topic, claim, source\n  - IDs use the node type as prefix, e.g. `file:path`, `function:path:name`, `config:path`, `article:path`\n- `edges[]` — each has {source, target, type, direction, weight}\n  - Key types: imports, contains, calls, depends_on, configures, documents, deploys, triggers, contains_flow, flow_step, related, cites\n- `layers[]` — each has {id, name, description, nodeIds[]}\n- `tour[]` — each has {order, title, description, nodeIds[]}\n\n## How to Read Efficiently\n\n1. Use Grep to search within the JSON for relevant entries BEFORE reading the full file\n2. Only read sections you need — don't dump the entire graph into context\n3. Node names and summaries are the most useful fields for understanding\n4. Edges tell you how components connect — follow imports and calls for dependency chains\n\n## Instructions\n\n1. **Resolve the data directory `$UA_DIR`.** Run `UA_DIR=$([ -d .understand-anything ] && echo .understand-anything || echo .ua)` — this is the legacy `.understand-anything/` when it already exists, otherwise the new `.ua/`. Check that `$UA_DIR/knowledge-graph.json` exists. If not, tell the user to run `/understand` first.\n\n2. **Check graph freshness before using graph-derived context**:\n   - Read `project.gitCommitHash` from the graph metadata as `GRAPH_COMMIT_RAW`. Resolve it as a commit before using it in any Git diff, then compare it with `git rev-parse HEAD` and inspect project-scoped committed and working-tree changes from the project root:\n     ```bash\n     GRAPH_COMMIT=$(git rev-parse --verify --end-of-options \"${GRAPH_COMMIT_RAW}^{commit}\" 2>/dev/null)\n     git rev-parse HEAD\n     git diff --name-only \"$GRAPH_COMMIT\" HEAD -- .\n     git diff --cached --name-only -- .\n     git diff --name-only -- .\n     git ls-files --others --exclude-standard -- .\n     ```\n   - The `-- .` pathspec is required: commits that only touch a sibling monorepo project must not make this graph stale. A hash mismatch alone is not stale when the project diff is empty.\n   - Ignore the selected data directory (`.ua/` or legacy `.understand-anything/`) in every command's output because it contains generated graph artifacts, not project source drift.\n   - If the committed diff or any working-tree command reports project files, warn before explaining that graph-derived context may omit those changes. Suggest: Run `/understand` to refresh the graph.\n   - Run the commit diff only when `GRAPH_COMMIT_RAW` resolves successfully. If the graph commit or Git metadata is missing, invalid, or unavailable, give a brief best-effort warning and continue instead of blocking.\n\n3. **Find the target node** — use Grep to search the knowledge graph for the component: \"$ARGUMENTS\"\n   - For file paths (e.g., `src/auth/login.ts`): search for `\"filePath\"` matches\n   - For function notation (e.g., `src/auth/login.ts:verifyToken`): search for the function name in `\"name\"` fields filtered by the file path\n   - Note the exact node `id`, `type`, `summary`, `tags`, and `complexity`\n\n4. **Find all connected edges** — Grep for the target node's ID in the edges section:\n   - `\"source\"` matches → things this node calls/imports/depends on (outgoing)\n   - `\"target\"` matches → things that call/import/depend on this node (incoming)\n   - Note the connected node IDs and edge types\n\n5. **Read connected nodes** — for each connected node ID from step 4, Grep for those IDs in the nodes section to get their `name`, `summary`, and `type`. This builds the component's neighborhood.\n\n6. **Identify the layer** — Grep for the target node's ID in the `\"layers\"` section to find which architectural layer it belongs to and that layer's description.\n\n7. **Read the actual source file** — Read the source file at the node's `filePath` for the deep-dive analysis.\n\n8. **Explain the component in context**:\n   - Its role in the architecture (which layer, why it exists)\n   - Internal structure (functions, classes it contains — from `contains` edges)\n   - External connections (what it imports, what calls it, what it depends on — from edges)\n   - Data flow (inputs → processing → outputs — from source code)\n   - Explain clearly, assuming the reader may not know the programming language\n   - Highlight any patterns, idioms, or complexity worth understanding","author":"@Egonex-AI","ownerProfile":null,"authorContacts":null,"sourceUrl":"https://github.com/Egonex-AI/Understand-Anything/tree/main/understand-anything-plugin/skills/understand-explain","license":"MIT","category":"writing","lang":"en","tokens":1153,"stars":0,"calls30d":1,"claimed":false,"visibility":"public","origin":"crawler","version":"0.1.0","createdAt":"2026-08-22","updatedAt":"2026-08-22","files":[],"requires":{"mcp":[],"tools":[]},"safety":{"flags":[],"scannedAt":"2026-08-22","hasScripts":false,"networkEndpoints":[]}}