Netmex MCP

A lightweight and extendable Model Context Protocol (MCP) server toolkit for building custom tools that integrate with AI assistants.

This package provides a ready-to-use MCP server, a clean structure for defining tools, and the option for developers to add their own tools without modifying the package.

Installation

npm install @netmex/mcp

Or with yarn:

yarn add @netmex/mcp

Related MCP server: SimpleMCP

Usage

After installing, you can run the MCP server using:

npx netmex-mcp

Creating Custom Tools

To add your own tools, create a tool file inside a mcp-tools/ directory in your project root:

Example Tool (TypeScript)

import type { Tool } from "@netmex/mcp/types";

const GreetTool: Tool = {
    name: "greet",
    description: "Returns a friendly greeting",
    inputSchema: {
        type: "object",
        properties: {
            name: { type: "string", description: "Name to greet" }
        },
        required: ["name"]
    },
    handler: async ({ name }) => ({
        content: [
            {
                type: "text",
                text: `Hello, ${name}!`
            }
        ]
    })
};

export default GreetTool;

Using Tools Inside Your Project

Once placed inside mcp-tools/, tools are automatically discovered by the loader and exposed to MCP clients.

No registration needed. No editing package code. Just drop the tool file in place.

Accessing Tool Input

Each tool receives structured arguments, validated according to its inputSchema.

Recommended Directory Layout

your-project/
├── mcp-tools/
│   ├── GreetTool.ts
│   └── AnotherTool.ts
├── node_modules/
├── package.json
└── ...

NPM Plugin Tools

You can also install tools from npm. Any dependency whose name starts with:

netmex-mcp-tool-

will be auto-loaded by the server.

Example:

npm install netmex-mcp-tool-analytics

Handling Errors

If a tool throws or returns an invalid value, the server automatically returns a JSON-RPC error:

{
  "error": {
    "code": -32603,
    "message": "Internal error",
    "data": { "details": "Something went wrong" }
  }
}

Use try/catch inside handlers for custom error responses.

Built-In Tools

This package includes a few tools by default:

• about

• hello

• (more coming soon)

Development

To build the MCP server locally:

npm install
npm run build

To start it directly:

npm run start

More About MCP

For more information on the Model Context Protocol, visit the official MCP documentation.

License

This project is licensed under the MIT License.