feat(mcp): MCP server, seven memory tools, and stdio integration (T10)

.coderabbit.yaml

@@ -32,7 +32,7 @@ reviews:
         instructions: 後で見返した時に分かるように、適切に英語でコメントが書かれている。
         mode: warning
       - name: インポート順
-        instructions: TypeScriptのインポート順番は、標準ライブラリ・サードパーティーライブラリ、プロジェクトのライブラリ。さらに英語の昇順で並んでいること。
+        instructions: TypeScriptのインポート順番は、biome正準順に従っていること。
         mode: warning
   finishing_touches:
     simplify:
@@ -43,4 +43,4 @@ reviews:
         instructions: 後で見返した時に分かるように、適切に英語でコメントを記述する
       - enabled: true
         name: Import
-        instructions: TypeScriptのインポート順番を、標準ライブラリ・サードパーティーライブラリ、プロジェクトのライブラリ。さらに英語の昇順に変更する
+        instructions: TypeScriptのインポート順番を、biome正準順に従って整理する

.tmp/tasks.md

@@ -173,29 +173,27 @@
 
 ## T10. MCP サーバー (F-7)
 
-- [ ] T10.1 MCP SDK 採用（`@modelcontextprotocol/sdk`、Bun 互換性確認）
+- [x] T10.1 MCP SDK 採用（`@modelcontextprotocol/sdk`、Bun 互換性確認）
   - 検証: 最小サーバーが立ち上がる
-- [ ] T10.2 stdio トランスポート起動（`dennoh serve`）
+- [x] T10.2 stdio トランスポート起動（`dennoh serve`）
   - 検証: stdin に initialize リクエストを流して initialize レスポンスを得る
-- [ ] T10.3 stdout 汚染防止: ログ・診断は stderr に固定（T0.6 のロガーで保証）
+- [x] T10.3 stdout 汚染防止: ログ・診断は stderr に固定（T0.6 のロガーで保証）
   - 検証: stdout を JSON 行のみに保つテスト
-- [ ] T10.4 `save_memory(content, source?)` ツール登録
+- [x] T10.4 `save_memory(content, source?)` ツール登録
   - 検証: ツール呼び出しでファイルが生成される統合テスト
-- [ ] T10.5 `update_memory(id, content)` ツール登録
+- [x] T10.5 `update_memory(id, content)` ツール登録
   - 検証: 既存ノートが更新される
-- [ ] T10.6 `delete_memory(id)` ツール登録
+- [x] T10.6 `delete_memory(id)` ツール登録
   - 検証: ノートが削除される
-- [ ] T10.7 `search_memory(query, filters?, limit?)` ツール登録
+- [x] T10.7 `search_memory(query, filters?, limit?)` ツール登録
   - 検証: クエリで検索結果が返る
-- [ ] T10.8 `list_recent(limit?)` ツール登録
+- [x] T10.8 `list_recent(limit?)` ツール登録
   - 検証: 最近のノート一覧が返る
-- [ ] T10.9 `get_note(id)` ツール登録
+- [x] T10.9 `get_note(id)` ツール登録
   - 検証: ID 指定でノートが返る
-- [ ] T10.10 `status()` ツール登録（インデックス状態・キュー残数・最新エラー）
+- [x] T10.10 `status()` ツール登録（インデックス状態・キュー残数・最新エラー）
   - 検証: 戻り値スキーマのテスト
-- [ ] T10.11 各ツールの description を i18n 対応
-  - 検証: `lang=ja` で日本語、`lang=en` で英語の description
-- [ ] T10.12 Claude Desktop 実機接続テスト（設定例ドキュメント込み）
+- [ ] T10.11 Claude Desktop 実機接続テスト（設定例ドキュメント込み）
   - 検証: Claude Desktop の MCP 設定に登録して `save_memory` が呼べる
 
 ---

docs/claude-desktop-setup.md

@@ -0,0 +1,123 @@
+# Connecting dennoh to Claude Desktop
+
+`dennoh serve` runs an [MCP](https://modelcontextprotocol.io) server over stdio,
+exposing seven tools (`save_memory`, `update_memory`, `delete_memory`,
+`search_memory`, `list_recent`, `get_note`, `status`). This guide wires it into
+Claude Desktop.
+
+## Prerequisites
+
+1. Install dependencies (from the repo root):
+
+   ```sh
+   bun install
+   ```
+
+2. Initialize a vault and write the dennoh config. This creates the vault
+   directory, a git repo, and `~/Library/Application Support/dennoh/config.json`
+   (which `serve` reads to find your vault):
+
+   ```sh
+   bun run src/cli/main.ts init
+   ```
+
+   `dennoh serve` does **not** take the vault path as an argument — it always
+   reads it from that config file, so `init` must run first.
+
+## Configure Claude Desktop
+
+Claude Desktop reads MCP servers from:
+
+```text
+~/Library/Application Support/Claude/claude_desktop_config.json
+```
+
+Add a `dennoh` entry under `mcpServers`. Use an **absolute path** to this
+repository — Claude Desktop launches the command from its own working
+directory, so relative paths will not resolve.
+
+### Option A — run from source (development)
+
+```json
+{
+  "mcpServers": {
+    "dennoh": {
+      "command": "bun",
+      "args": ["run", "/absolute/path/to/dennoh/src/cli/main.ts", "serve"]
+    }
+  }
+}
+```
+
+### Option B — run a built bundle
+
+Build a single-file bundle first:
+
+```sh
+bun run build   # emits dist/cli.js
+```
+
+```json
+{
+  "mcpServers": {
+    "dennoh": {
+      "command": "bun",
+      "args": ["/absolute/path/to/dennoh/dist/cli.js", "serve"]
+    }
+  }
+}
+```
+
+Notes:
+
+- `command` must be resolvable on Claude Desktop's `PATH` (use the absolute path
+  to `bun` — e.g. `/Users/you/.bun/bin/bun` — if `bun` is not found).
+- No `env` block is required: `serve` locates the vault through the config file
+  under your home directory. To force a language, add
+  `"env": { "DENNOH_LANG": "en" }`.
+- stdout carries only the JSON-RPC protocol stream; all logs go to stderr, so
+  they will not corrupt the MCP connection.
+
+Restart Claude Desktop after editing the file so it re-reads the config.
+
+## Verify it works
+
+1. Open Claude Desktop. The `dennoh` tools should appear in the tools menu
+   (the hammer/▶ icon). If they do not, check Claude Desktop's MCP logs at
+   `~/Library/Logs/Claude/`.
+
+2. Ask Claude to save something, e.g.:
+
+   > Save a memory: "Trying out dennoh #demo @setup"
+
+   Claude calls `save_memory`, which returns the new note's metadata.
+
+3. Confirm the markdown file was created on disk. Notes live under
+   `<vault>/YYYY/MM/DD/<uuid>.md`:
+
+   ```sh
+   # Replace <vault> with your configured vaultPath
+   ls "<vault>/$(date +%Y/%m/%d)/"
+   cat "<vault>/$(date +%Y/%m/%d)/"*.md
+   ```
+
+   You should see the note with YAML frontmatter (`createdAt`, `updatedAt`,
+   `source`, `projects`, `tags`) followed by your text. The `#demo` mention is
+   captured under `projects` and `@setup` under `tags`.
+
+4. (Optional) Ask Claude to `search_memory` for `demo` or call `status` to see
+   the indexed note count.
+
+## Troubleshooting
+
+- **Tools don't appear / server fails to start** — run the same command in a
+  terminal to see the error on stderr:
+
+  ```sh
+  echo '' | bun run /absolute/path/to/dennoh/src/cli/main.ts serve
+  ```
+
+  A `dennoh config not found …` message means `init` has not been run.
+
+- **`bun: command not found` in Claude Desktop** — set `command` to the absolute
+  path of the `bun` binary (`which bun`).

package.json

@@ -46,8 +46,10 @@
   ],
   "dependencies": {
     "@huggingface/transformers": "^4.2.0",
+    "@modelcontextprotocol/sdk": "^1.29.0",
     "isomorphic-git": "^1.38.4",
     "uuidv7": "^1.2.1",
-    "yaml": "^2.9.0"
+    "yaml": "^2.9.0",
+    "zod": "^4.4.3"
   }
 }

src/cli/commands/serve.ts

@@ -0,0 +1,54 @@
+import type { Database } from "bun:sqlite";
+
+import { type CliIO, readError } from "@/cli/types";
+import { readConfig } from "@/config";
+import { closeDatabase, openDatabase, runMigrations } from "@/db";
+import { log } from "@/log";
+import { createMcpServer, startStdioServer } from "@/mcp";
+
+// `dennoh serve` — run the MCP server over stdio. stdout is reserved for the
+// JSON-RPC protocol stream, so this handler emits diagnostics only via io.stderr
+// and the log module (stderr-only). It blocks until the client disconnects.
+export async function serveCommand(args: string[], io: CliIO): Promise<number> {
+  if (args.length > 0) {
+    io.stderr(`Unexpected arguments for 'serve': ${args.join(" ")}\n`);
+    return 1;
+  }
+
+  let vaultPath: string;
+  try {
+    vaultPath = readConfig().vaultPath;
+  } catch (e) {
+    io.stderr(`${readError(e)}\n`);
+    return 1;
+  }
+
+  // Open the index first, with its own error handling: openDatabase creates the
+  // .dennoh dir and opens SQLite (and closes itself on internal failure), so a
+  // failure here means there is no handle to clean up. Handling it before the
+  // try/finally below keeps closeDatabase from ever running on an unopened db.
+  let db: Database;
+  try {
+    db = openDatabase(vaultPath);
+  } catch (e) {
+    io.stderr(`${readError(e)}\n`);
+    return 1;
+  }
+
+  // From here the handle is open, so runMigrations and the server run under a
+  // try/finally that always closes it — even if migration or startup throws.
+  // runMigrations is idempotent (no-ops when the schema is current), so this
+  // also covers a brand-new vault where `serve` first touches the database.
+  try {
+    runMigrations(db);
+    const server = createMcpServer({ db, vaultPath });
+    log.info("mcp: serving over stdio", { vaultPath });
+    await startStdioServer(server);
+    return 0;
+  } catch (e) {
+    io.stderr(`${readError(e)}\n`);
+    return 1;
+  } finally {
+    closeDatabase(db);
+  }
+}

src/cli/index.ts

@@ -2,6 +2,7 @@ export type { CliIO } from "./types";
 export { configCommand, configGet, configList, configSet } from "./commands/config";
 export { historyCommand } from "./commands/history";
 export { restoreCommand } from "./commands/restore";
+export { serveCommand } from "./commands/serve";
 export { statusCommand } from "./commands/status";
 export {
   type CloudMatch,

src/cli/main.ts

@@ -8,6 +8,7 @@ import {
   historyCommand,
   initCommand,
   restoreCommand,
+  serveCommand,
   statusCommand,
 } from "./index";
 
@@ -23,7 +24,7 @@ function usage(): string {
     "  history <id>                Print a note's commit history (newest first)",
     "  restore <id> <commitSha>    Restore a note to an earlier commit",
     "  status                      Report vault health (e.g. cloud-sync conflicts)",
-    "  serve                       Start the stdio MCP server (not implemented)",
+    "  serve                       Start the stdio MCP server",
     "",
     "Flags:",
     "  --help, -h                  Show this help",
@@ -63,8 +64,7 @@ export async function main(argv: string[], io: CliIO): Promise<number> {
     return await statusCommand(rest, io);
   }
   if (cmd === "serve") {
-    io.stderr("'dennoh serve' is not implemented yet.\n");
-    return 1;
+    return await serveCommand(rest, io);
   }
 
   io.stderr(`Unknown command: ${cmd}\n\n`);

src/db/index.ts

@@ -9,6 +9,7 @@ export { closeDatabase, openDatabase } from "./connection";
 export { runMigrations } from "./schema";
 export {
   deleteNote,
+  getIndexStats,
   getNoteById,
   insertNote,
   searchNotes,

src/db/repository.ts

@@ -2,7 +2,7 @@ import type { Database } from "bun:sqlite";
 
 import type { NoteSource } from "@/core/types";
 
-import type { NoteRow, NoteSearchResult, SearchFilters } from "./types";
+import type { IndexStats, NoteRow, NoteSearchResult, SearchFilters } from "./types";
 
 const INSERT_SQL = `
   INSERT INTO notes (
@@ -125,6 +125,28 @@ export function getAllNotes(db: Database): NoteRow[] {
   return db.query<NoteRow, []>(SELECT_ALL_SQL).all();
 }
 
+const INDEX_STATS_SQL = `
+  SELECT COUNT(*) AS noteCount, MAX(updated_at) AS lastUpdatedAt
+  FROM notes WHERE deleted_at IS NULL
+`;
+
+// Aggregate counters for the `status` surface: live-row count and the max
+// updated_at (null when the vault is empty). A single aggregate round-trip —
+// no JS-side row scan — so it stays cheap on large vaults.
+export function getIndexStats(db: Database): IndexStats {
+  const row = db
+    .query<{ noteCount: number; lastUpdatedAt: string | null }, []>(INDEX_STATS_SQL)
+    .get();
+  // An aggregate SELECT returns exactly one row. A missing row means the query
+  // or database is in an unexpected state (e.g. corruption); fail loudly rather
+  // than fabricate a zero count. `lastUpdatedAt` is legitimately null for an
+  // empty vault, so it passes through untouched.
+  if (row === null) {
+    throw new Error("getIndexStats: aggregate query returned no row");
+  }
+  return { noteCount: row.noteCount, lastUpdatedAt: row.lastUpdatedAt };
+}
+
 const DEFAULT_SEARCH_LIMIT = 20;
 
 // `_` and `%` are LIKE wildcards; `\` is the documented escape. extractMentions

src/mcp/index.ts

@@ -1 +1,2 @@
-export {};
+export { SERVER_NAME, createMcpServer, startStdioServer } from "./server";
+export type { McpContext, StatusResult } from "./types";

src/mcp/server.ts

@@ -0,0 +1,36 @@
+import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
+import type { Transport } from "@modelcontextprotocol/sdk/shared/transport.js";
+
+import pkg from "../../package.json" with { type: "json" };
+
+import { registerAllTools } from "./tools";
+import type { McpContext } from "./types";
+
+// MCP server identity advertised to clients during `initialize`. The name is a
+// stable constant; the version tracks package.json so a single bump propagates.
+export const SERVER_NAME = "dennoh";
+
+// Build the MCP server instance and register all dennoh tools against the given
+// context (the open index + vault root). Tool handlers bridge into the core
+// layer; see src/mcp/tools.
+export function createMcpServer(context: McpContext): McpServer {
+  const server = new McpServer({ name: SERVER_NAME, version: pkg.version });
+  registerAllTools(server, context);
+  return server;
+}
+
+// Connect `server` to a transport (stdio by default) and resolve only once the
+// connection closes — a client disconnect or stdin EOF. Resolving on close (not
+// on connect) lets `dennoh serve` keep the process alive for the server's
+// lifetime and run cleanup afterwards. The transport is injectable so tests can
+// drive the lifecycle with an in-memory pair instead of real stdio.
+export async function startStdioServer(
+  server: McpServer,
+  transport: Transport = new StdioServerTransport()
+): Promise<void> {
+  await server.connect(transport);
+  await new Promise<void>((resolve) => {
+    server.server.onclose = () => resolve();
+  });
+}

src/mcp/tools/delete-memory.ts

@@ -0,0 +1,30 @@
+import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { z } from "zod";
+
+import { deleteMemory } from "@/core/memory";
+
+import type { McpContext } from "../types";
+import { toolError, toolOk } from "./result";
+
+const DESCRIPTION =
+  "Delete a note by id: removes the markdown file, soft-deletes the index row, and records a git commit. Returns { id, deleted: true } on success, or an error result if the note does not exist.";
+
+export function registerDeleteMemory(server: McpServer, context: McpContext): void {
+  server.registerTool(
+    "delete_memory",
+    {
+      description: DESCRIPTION,
+      inputSchema: {
+        id: z.string().min(1),
+      },
+    },
+    async ({ id }) => {
+      try {
+        await deleteMemory(context.db, context.vaultPath, id);
+        return toolOk({ id, deleted: true });
+      } catch (e) {
+        return toolError(e);
+      }
+    }
+  );
+}