mcp-server

[](https://github.com/moleculerjs/mcp-server/actions/workflows/test.yml) [](https://www.npmjs.com/package/@moleculer/mcp-server)

MCP server mixin for Moleculer API Gateway (moleculer-web).

Expose your Moleculer microservices to AI assistants (Claude, GPT, etc.) via the Model Context Protocol.

<video controls src="docs/Code_PIxZeLiRX3.mp4" title="Introduction to MCP Server"></video>

• Auto-discovery — Moleculer actions are automatically registered as MCP tools with proper schemas
• Schema conversion — fastest-validator params are converted to Zod schemas automatically
• Tool annotations — REST method-based auto-detection of readOnlyHint, destructiveHint, idempotentHint
• Service filtering — Whitelist services or exclude specific actions via glob patterns
• MCP metadata — Fine-grained control over tool name, description, and annotations per action
• Built-in broker tools — List nodes, services, actions, events + generic call/emit tools
• Streamable HTTP transport — Standards-compliant MCP server with session management and resumability

npm i @moleculer/mcp-server moleculer-web

Add the MCP server mixin to your API Gateway service:

import ApiGateway from "moleculer-web";
import { McpServerMixin } from "@moleculer/mcp-server";

// api.service.js
export default {
  name: "api",
  mixins: [ApiGateway, McpServerMixin()],
  settings: {
    port: 3000
  }
};

That's it! The MCP server is available at http://localhost:3000/mcp. All your Moleculer actions are automatically exposed as MCP tools.

When the broker starts, the mixin scans the service registry and r