Add MCP smoke test client

README.md

@@ -43,7 +43,7 @@ npm install
 Run:
 
 ```bash
-node mcp_server.mjs
+npm run mcp
 ```
 
 If the `m2pack` binary is not at `build/m2pack`, set:
@@ -62,6 +62,12 @@ Exposed tools:
 - `pack_export_client_config`
 - `pack_binary_info`
 
+Smoke test:
+
+```bash
+npm run mcp:smoke
+```
+
 ## Build
 
 ```bash

docs/mcp.md

@@ -19,7 +19,7 @@ cd /path/to/m2pack-secure
 npm install
 cmake -S . -B build
 cmake --build build -j
-node mcp_server.mjs
+npm run mcp
 ```
 
 ## Environment
@@ -78,6 +78,21 @@ Inputs:
 
 No input. Returns the active `m2pack` binary path.
 
+## Smoke test
+
+Run a local roundtrip test with the bundled Node MCP client:
+
+```bash
+npm run mcp:smoke
+```
+
+That test:
+
+- spawns `mcp_server.mjs`
+- connects over stdio
+- lists tools
+- calls `pack_binary_info`
+
 ## Claude Desktop style config example
 
 ```json

package.json

@@ -3,6 +3,10 @@
   "version": "0.1.0",
   "private": true,
   "type": "module",
+  "scripts": {
+    "mcp": "node mcp_server.mjs",
+    "mcp:smoke": "node scripts/mcp_smoke_test.mjs"
+  },
   "dependencies": {
     "@modelcontextprotocol/sdk": "^1.29.0",
     "zod": "^3.25.76"

scripts/mcp_smoke_test.mjs

@@ -0,0 +1,50 @@
+#!/usr/bin/env node
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
+import { Client } from "@modelcontextprotocol/sdk/client/index.js";
+import { StdioClientTransport } from "@modelcontextprotocol/sdk/client/stdio.js";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const repoRoot = path.resolve(__dirname, "..");
+
+async function main() {
+  const client = new Client({
+    name: "m2pack-smoke-test",
+    version: "0.1.0",
+  });
+
+  const transport = new StdioClientTransport({
+    command: "node",
+    args: [path.join(repoRoot, "mcp_server.mjs")],
+    cwd: repoRoot,
+    env: {
+      ...process.env,
+      M2PACK_BINARY: process.env.M2PACK_BINARY || path.join(repoRoot, "build", "m2pack"),
+    },
+    stderr: "inherit",
+  });
+
+  await client.connect(transport);
+
+  const tools = await client.listTools();
+  const binaryInfo = await client.callTool({
+    name: "pack_binary_info",
+    arguments: {},
+  });
+
+  console.log(JSON.stringify({
+    ok: true,
+    tool_count: tools.tools.length,
+    tool_names: tools.tools.map((tool) => tool.name),
+    binary_info: binaryInfo.structuredContent ?? null,
+  }, null, 2));
+
+  await transport.close();
+}
+
+main().catch((error) => {
+  console.error(error);
+  process.exit(1);
+});