fix mcp --index store selection

CHANGELOG.md

@@ -13,6 +13,7 @@
 - MCP: seed llama.cpp/GGML quiet env vars before launching `qmd mcp` so native logs cannot pollute stdio JSON-RPC framing. #593
 - CLI: remove CommonJS `require()` calls from ESM index path normalization so `qmd --index <path>` no longer crashes with `ERR_AMBIGUOUS_MODULE_SYNTAX` on Node 22+. #634
 - Windows CUDA: serialize llama.cpp embedding/reranking contexts by default to avoid intermittent `ggml-cuda.cu:98` crashes in `qmd query`; set `QMD_EMBED_PARALLELISM` to opt back into parallel contexts if your driver is stable. #519
+- MCP: make `qmd mcp --index <name>` use the selected index for both foreground and daemon HTTP servers instead of falling back to the default store. #343
 - GPU: respect explicit `QMD_LLAMA_GPU=metal|vulkan|cuda` backend overrides instead of always using auto GPU selection. #529
 - Fix: preserve original filename case in `handelize()`. The previous
   `.toLowerCase()` call made indexed paths unreachable on case-sensitive

src/cli/qmd.ts

@@ -3253,9 +3253,10 @@ if (isMain) {
           const logPath = resolve(cacheDir, "mcp.log");
           const logFd = openSync(logPath, "w"); // truncate — fresh log per daemon run
           const selfPath = fileURLToPath(import.meta.url);
+          const indexArgs = cli.values.index ? ["--index", String(cli.values.index)] : [];
           const spawnArgs = selfPath.endsWith(".ts")
-            ? ["--import", pathJoin(dirname(selfPath), "..", "..", "node_modules", "tsx", "dist", "esm", "index.mjs"), selfPath, "mcp", "--http", "--port", String(port)]
-            : [selfPath, "mcp", "--http", "--port", String(port)];
+            ? ["--import", pathJoin(dirname(selfPath), "..", "..", "node_modules", "tsx", "dist", "esm", "index.mjs"), selfPath, ...indexArgs, "mcp", "--http", "--port", String(port)]
+            : [selfPath, ...indexArgs, "mcp", "--http", "--port", String(port)];
           const child = nodeSpawn(process.execPath, spawnArgs, {
             stdio: ["ignore", logFd, logFd],
             detached: true,
@@ -3275,7 +3276,7 @@ if (isMain) {
         process.removeAllListeners("SIGINT");
         const { startMcpHttpServer } = await import("../mcp/server.js");
         try {
-          await startMcpHttpServer(port);
+          await startMcpHttpServer(port, { dbPath: getDbPath() });
         } catch (e: any) {
           if (e?.code === "EADDRINUSE") {
             console.error(`Port ${port} already in use. Try a different port with --port.`);
@@ -3286,7 +3287,7 @@ if (isMain) {
       } else {
         // Default: stdio transport
         const { startMcpServer } = await import("../mcp/server.js");
-        await startMcpServer();
+        await startMcpServer({ dbPath: getDbPath() });
       }
       break;
     }

src/mcp/server.ts

@@ -538,7 +538,11 @@ Intent-aware lex (C++ performance, not sports):
 // Transport: stdio (default)
 // =============================================================================
 
-export async function startMcpServer(): Promise<void> {
+export type McpStartupOptions = {
+  dbPath?: string;
+};
+
+export async function startMcpServer(options: McpStartupOptions = {}): Promise<void> {
   // Opt into production mode when the MCP server is actually started, not
   // when this module is merely imported for its exports. Importing the module
   // at the top level flipped the global production flag and broke test
@@ -547,7 +551,7 @@ export async function startMcpServer(): Promise<void> {
   enableProductionMode();
   const configPath = getConfigPath();
   const store = await createStore({
-    dbPath: getDefaultDbPath(),
+    dbPath: options.dbPath ?? getDefaultDbPath(),
     ...(existsSync(configPath) ? { configPath } : {}),
   });
   const server = await createMcpServer(store);
@@ -569,14 +573,17 @@ export type HttpServerHandle = {
  * Start MCP server over Streamable HTTP (JSON responses, no SSE).
  * Binds to localhost only. Returns a handle for shutdown and port discovery.
  */
-export async function startMcpHttpServer(port: number, options?: { quiet?: boolean }): Promise<HttpServerHandle> {
+export async function startMcpHttpServer(
+  port: number,
+  options: ({ quiet?: boolean } & McpStartupOptions) = {},
+): Promise<HttpServerHandle> {
   // See startMcpServer() for the rationale — flip production mode here so the
   // HTTP transport resolves the real database path, without leaking state into
   // callers that only import this module for its exports (e.g. tests).
   enableProductionMode();
   const configPath = getConfigPath();
   const store = await createStore({
-    dbPath: getDefaultDbPath(),
+    dbPath: options.dbPath ?? getDefaultDbPath(),
     ...(existsSync(configPath) ? { configPath } : {}),
   });
 

test/cli.test.ts

@@ -1403,13 +1403,17 @@ describe("mcp http daemon", () => {
   }
 
   /** Spawn a foreground HTTP server (non-blocking) and return the process */
-  function spawnHttpServer(port: number): import("child_process").ChildProcess {
-    const proc = spawn(tsxBin, [qmdScript, "mcp", "--http", "--port", String(port)], {
+  function spawnHttpServer(
+    port: number,
+    options: { args?: string[]; env?: Record<string, string> } = {},
+  ): import("child_process").ChildProcess {
+    const proc = spawn(tsxBin, [qmdScript, ...(options.args ?? []), "mcp", "--http", "--port", String(port)], {
       cwd: fixturesDir,
       env: {
         ...process.env,
         INDEX_PATH: daemonDbPath,
         QMD_CONFIG_DIR: daemonConfigDir,
+        ...options.env,
       },
       stdio: ["ignore", "pipe", "pipe"],
     });
@@ -1481,11 +1485,62 @@ describe("mcp http daemon", () => {
       const body = await res.json();
       expect(body.status).toBe("ok");
     } finally {
+      const closed = new Promise(r => proc.once("close", r));
       proc.kill("SIGTERM");
-      await new Promise(r => proc.on("close", r));
+      await closed;
     }
   });
 
+  test("foreground HTTP server honors --index when selecting the store", async () => {
+    const customIndex = "mcp-alt-index";
+    const customCacheDir = join(daemonTestDir, `cache-index-${Date.now()}-${Math.random().toString(16).slice(2)}`);
+    const customConfigDir = join(daemonTestDir, `config-index-${Date.now()}-${Math.random().toString(16).slice(2)}`);
+    await mkdir(customCacheDir, { recursive: true });
+    await mkdir(customConfigDir, { recursive: true });
+
+    const addResult = await runQmd(
+      ["--index", customIndex, "collection", "add", fixturesDir, "--name", "mcp-fixtures"],
+      {
+        dbPath: daemonDbPath,
+        configDir: customConfigDir,
+        env: {
+          INDEX_PATH: "",
+          XDG_CACHE_HOME: customCacheDir,
+        },
+      },
+    );
+    expect(addResult.exitCode).toBe(0);
+
+    const port = randomPort();
+    const proc = spawnHttpServer(port, {
+      args: ["--index", customIndex],
+      env: {
+        INDEX_PATH: "",
+        XDG_CACHE_HOME: customCacheDir,
+        QMD_CONFIG_DIR: customConfigDir,
+      },
+    });
+
+    try {
+      const ready = await waitForServer(port);
+      expect(ready).toBe(true);
+
+      const res = await fetch(`http://localhost:${port}/query`, {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ searches: [{ type: "lex", query: "authentication" }], limit: 5 }),
+      });
+      expect(res.status).toBe(200);
+      const body = await res.json();
+      const files = body.results.map((r: { file: string }) => r.file);
+      expect(files.some((file: string) => file.includes("mcp-fixtures/notes/meeting.md"))).toBe(true);
+    } finally {
+      const closed = new Promise(r => proc.once("close", r));
+      proc.kill("SIGTERM");
+      await closed;
+    }
+  }, 10000);
+
   // -------------------------------------------------------------------------
   // Daemon lifecycle
   // -------------------------------------------------------------------------