https://github.com/lucianoayres/mcp-server-node
MCP Server built in Node.js that demonstrates how to build an MCP server with a custom tool, including one that loads an environment variable from a configuration file, to integrate seamlessly with AI-assisted environments like Cursor AI.
https://github.com/lucianoayres/mcp-server-node
ai cursor mcp-server
Last synced: 6 months ago
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MCP Server built in Node.js that demonstrates how to build an MCP server with a custom tool, including one that loads an environment variable from a configuration file, to integrate seamlessly with AI-assisted environments like Cursor AI.
- Host: GitHub
- URL: https://github.com/lucianoayres/mcp-server-node
- Owner: lucianoayres
- Created: 2025-03-22T10:42:21.000Z (8 months ago)
- Default Branch: main
- Last Pushed: 2025-03-22T20:28:00.000Z (8 months ago)
- Last Synced: 2025-03-22T21:32:00.729Z (8 months ago)
- Topics: ai, cursor, mcp-server
- Language: JavaScript
- Homepage:
- Size: 6.84 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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- awesome-mcp-servers - **mcp-server-node** - MCP Server implemented in JavaScript using Node.js that demonstrates how to build an MCP server with a custom prompt and custom tools, including one that loads an environment variable from a configuration file, to integrate seamlessly with AI-assisted environments like Cursor IDE. `javascript` `ai` `cursor` `mcp-server` `nodejs` `npm install lucianoayres/mcp-server-node` (🤖 AI/ML)
- awesome-mcp-servers - **mcp-server-node** - MCP Server implemented in JavaScript using Node.js that demonstrates how to build an MCP server with a custom prompt and custom tools, including one that loads an environment variable from a configuration file, to integrate seamlessly with AI-assisted environments like Cursor IDE. `javascript` `ai` `cursor` `mcp-server` `nodejs` `npm install lucianoayres/mcp-server-node` (AI/ML)
README
# MCP Server in Node.js
## Overview
**MCP (Model Context Protocol)** is a framework that allows you to integrate custom tools into AI-assisted development environments—such as Cursor AI. MCP servers expose functionality (like data retrieval or code analysis) so that an LLM-based IDE can call these tools on demand. Learn more about MCP in the [Model Context Protocol Introduction](https://modelcontextprotocol.io/introduction).
This project demonstrates an MCP server built in Node.js that provides two basic tools. One tool, **add**, accepts two numbers and returns their sum, while the other, **getApiKey**, retrieves the API key from the environment (via the `API_KEY` variable).
## Requirements
- **Node.js:** Version 20 or higher is required.
## Features
- **MCP Integration:** Exposes tool functionality to LLM-based IDEs.
- **Addition Tool:** Accepts two numeric parameters and returns their sum.
- **Env Var Retrieval:** Demonstrates how to load an example environment variable from the configuration file.
- **Input Validation:** Uses [Zod](https://github.com/colinhacks/zod) for schema validation.
- **Standard I/O Transport:** Connects via `StdioServerTransport` for integration with development environments.
## Installation
1. **Clone the Repository**
```bash
git clone
cd
```
2. **Install Dependencies**
You can install the project dependencies in one of two ways:
**Option 1: Install using the existing `package.json`**
Simply run:
```bash
npm install
```
**Option 2: Install dependencies manually**
If you prefer, delete the existing `package.json` and install the required packages manually:
```bash
npm install @modelcontextprotocol/sdk @coinpaprika/api-nodejs-client zod
```
Then, update the newly generated `package.json` file to include the following line, which enables ES Modules:
```json
"type": "module"
```
## Integrating with Cursor AI
This project includes a `./cursor` subdirectory that contains an `mcp.json` file for configuring the MCP server. Cursor AI uses this file to automatically discover and launch your MCP server. Open the file and update the fields as follows:
### The `./cursor/mcp.json` Structure
Below is the full JSON structure of the configuration file:
```json
{
"mcpServers": {
"MCP Server Boilerplate": {
"command": "/path/to/node",
"args": ["/path/to/mcp-server.js"],
"env": {
"API_KEY": "abc-1234567890"
}
}
}
}
```
- **mcpServers:**
An object mapping server names to their configuration.
- **MCP Server Boilerplate:**
This is the key for your server configuration. You can name it as you like.
- **command:**
Specifies the absolute path to your Node.js executable. For example:
```
/home/john/.nvm/versions/node/v20.13.1/bin/node
```
- **args:**
An array containing the absolute path to your MCP server file. For example:
```
["/home/john/mcp-server-node/index.js"]
```
- **env:** (Optional)
Defines environment variables for your MCP server process. In this example, the `API_KEY` is set to `"abc-1234567890"`. Adjust this value as needed for your environment.
You can verify the absolute path to your Node.js executable by running `which node` in your terminal.
### Optional: Configuration Automation Scripts
Easily configure your local environment by automatically updating the mcp.json file with the correct absolute paths. To apply your local settings, run the following commands from your project root:
```bash
chmod +x ./scripts/update_config.sh
./scripts/update_config.sh
```
This script replaces the placeholder paths in mcp.json with your machine’s absolute paths for Python and the server script, ensuring your configuration settings are always accurate.
### Optional: Global Cursor settings
You can also move the `mcp.json` file to your global Cursor AI configuration directory located at `~/.cursor` to make the configuration available globally.
## Using the MCP Tool in Cursor Composer (Agent Mode)
With the MCP server integrated into Cursor AI and with Agent mode enabled in Cursor Composer, simply use a natural language prompt like:
```
add 3 and 5
```
or
```
what is my API key?
```
The AI agent will infer the available `add` or `getApiKey` tool from your MCP server and execute it accordingly.
## Code Overview
The project comprises the following key parts:
- **MCP Server Initialization:**
The MCP server is instantiated using `McpServer` from the MCP SDK and connected via `StdioServerTransport`.
- **Tool Definitions:**
- **add:**
Defined with a Zod schema that accepts two numbers (`a` and `b`) and returns their sum as text.
- **getApiKey:**
Retrieves the API key from the environment variable `API_KEY` and returns it as text.
## What is MCP?
**Model Context Protocol (MCP)** provides a standardized approach to integrate custom tools into AI-assisted development environments. With MCP, you can define tools that perform specific tasks—such as retrieving external data, validating code, or enforcing coding standards—and the AI assistant in your IDE can call these tools automatically based on context. This helps improve developer productivity, ensures consistent quality, and streamlines workflows.
## References & Resources
- [Model Context Protocol: typescript-sdk](https://github.com/modelcontextprotocol/typescript-sdk)
- [Use Your Own MCP on Cursor in 5 Minutes](https://dev.to/andyrewlee/use-your-own-mcp-on-cursor-in-5-minutes-1ag4)
- [Model Context Protocol Introduction](https://modelcontextprotocol.io/introduction)
## License
This project is licensed under the [MIT License](LICENSE).