Mock Data Generator MCP server

This MCP server implementation provides a mock server for the Model Context Protocol, useful for testing MCP clients without needing a real model server. It returns dummy responses to simulate a working MCP environment and can be configured to behave in different ways for testing purposes.

Installation

You can install the mock-data-mcp server using npm:

npm install @mistralai/mock-data-mcp

Alternatively, you can clone the repository and install dependencies:

git clone https://github.com/mistralai/mock-data-mcp.git
cd mock-data-mcp
npm install

Usage

Starting the Server

To start the MCP server, run:

npm start

This will start the server on port 8000 by default. You can modify the port by setting the PORT environment variable:

PORT=9000 npm start

Configuration

The server can be configured through environment variables:

# Set the port for the server to listen on
PORT=8000

# Control the message delay time (in milliseconds)
MESSAGE_DELAY=100

# Configure token generation rate (tokens per second)
TOKEN_RATE=20

# Enable debug logging
DEBUG=true

Testing with cURL

You can test the server with cURL commands:

# Test a basic request
curl -X POST http://localhost:8000/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "mistral-tiny",
    "messages": [
      {"role": "user", "content": "Hello, how are you?"}
    ]
  }'

Streaming Responses

To test streaming responses:

curl -X POST http://localhost:8000/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "mistral-tiny",
    "messages": [
      {"role": "user", "content": "Tell me about streaming responses"}
    ],
    "stream": true
  }'

API Endpoints

The mock server supports the following MCP endpoints:

• POST /v1/chat/completions: Generate chat completions
• GET /v1/models: List available models

Troubleshooting

Common Issues

If you encounter connection errors, verify:

• The server is running
• You're connecting to the correct port
• No firewall is blocking the connection

Logs

Enable debug logging to see detailed information about requests and responses:

DEBUG=true npm start

How to install this MCP server

For Claude Code

To add this MCP server to Claude Code, run this command in your terminal:

claude mcp add-json "mock-data-mcp" '{"command":"npx","args":["mock-data-mcp"]}'

See the official Claude Code MCP documentation for more details.

For Cursor

There are two ways to add an MCP server to Cursor. The most common way is to add the server globally in the ~/.cursor/mcp.json file so that it is available in all of your projects.

If you only need the server in a single project, you can add it to the project instead by creating or adding it to the .cursor/mcp.json file.

Adding an MCP server to Cursor globally

To add a global MCP server go to Cursor Settings > Tools & Integrations and click "New MCP Server".

When you click that button the ~/.cursor/mcp.json file will be opened and you can add your server like this:

{
    "mcpServers": {
        "mock-data-mcp": {
            "command": "npx",
            "args": [
                "mock-data-mcp"
            ]
        }
    }
}

Adding an MCP server to a project

To add an MCP server to a project you can create a new .cursor/mcp.json file or add it to the existing one. This will look exactly the same as the global MCP server example above.

How to use the MCP server

Once the server is installed, you might need to head back to Settings > MCP and click the refresh button.

The Cursor agent will then be able to see the available tools the added MCP server has available and will call them when it needs to.

You can also explicitly ask the agent to use the tool by mentioning the tool name and describing what the function does.

For Claude Desktop

To add this MCP server to Claude Desktop:

1. Find your configuration file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

2. Add this to your configuration file:

{
    "mcpServers": {
        "mock-data-mcp": {
            "command": "npx",
            "args": [
                "mock-data-mcp"
            ]
        }
    }
}

3. Restart Claude Desktop for the changes to take effect