npm-mcp

Instructions

Implementation Reference

• src/index.ts:692-717 (handler)

  The handler implementation for the "pkg" tool. It calls 'npm pkg' with arguments derived from the tool input.

  server.tool(
    "pkg",
    "Manage package.json fields programmatically",
    {
      path: z.string().describe("Absolute path to the package directory"),
      action: z.enum(["get", "set", "delete"]).describe("Action to perform"),
      field: z.string().describe("Field name (e.g. 'name', 'scripts.build', 'keywords')"),
      value: z.string().optional().describe("Value to set (required for set action, use JSON for objects/arrays)"),
    },
    async ({ path, action, field, value }) => {
      const args = ["pkg", action, field];
      if (action === "set" && value !== undefined) {
        args.push(value);
      }
      args.push("--json");
      try {
        const { stdout, stderr } = await run(args, path);
        return { content: [{ type: "text", text: stdout + stderr || "Done" }] };
      } catch (e: any) {
        return {
          content: [{ type: "text", text: `Error: ${e.stderr || e.message}` }],
          isError: true,
        };
      }
    },
  );