npm-mcp

Instructions

Implementation Reference

• src/index.ts:865-890 (handler)

  The "run-script" tool is registered and implemented directly in src/index.ts using the server.tool method. It constructs the command arguments and executes them using the 'run' helper.

  server.tool(
    "run-script",
    "Run a script defined in package.json",
    {
      path: z.string().describe("Absolute path to the package directory"),
      script: z.string().optional().describe("Script name to run (omit to list available scripts)"),
      args: z.array(z.string()).optional().describe("Arguments to pass to the script"),
    },
    async ({ path, script, args: scriptArgs }) => {
      const cmdArgs = script ? ["run", script] : ["run"];
      if (scriptArgs && scriptArgs.length > 0) {
        cmdArgs.push("--");
        cmdArgs.push(...scriptArgs);
      }
      if (!script) cmdArgs.push("--json");
      try {
        const { stdout, stderr } = await run(cmdArgs, path);
        return { content: [{ type: "text", text: stdout + stderr }] };
      } catch (e: any) {
        return {
          content: [{ type: "text", text: `Error: ${e.stdout || ""}${e.stderr || e.message}` }],
          isError: true,
        };
      }
    },
  );