Generate Secure Random Numbers and Tokens

Random Number MCP

Essential random number generation utilities from the Python standard library, including pseudorandom and cryptographically secure operations for integers, floats, weighted selections, list shuffling, and secure token generation.

Looking for the agent skill version? random-number-skills implements the same random number generation strategy as an agent skill instead of an MCP server.

Demo Video

https://github.com/user-attachments/assets/303a441a-2b10-47e3-b2a5-c8b51840e362

Tools

Setup

Claude Desktop

Add this to your Claude Desktop configuration file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "random-number": {
      "command": "uvx",
      "args": ["random-number-mcp"]
    }
  }
}

Tool Reference

random_int

Generate a random integer between low and high (inclusive).

Parameters:

• low (int): Lower bound (inclusive)
• high (int): Upper bound (inclusive)

Example:

{
  "name": "random_int",
  "arguments": {
    "low": 1,
    "high": 100
  }
}

random_float

Generate a random float between low and high.

Parameters:

• low (float, optional): Lower bound (default: 0.0)
• high (float, optional): Upper bound (default: 1.0)

Example:

{
  "name": "random_float",
  "arguments": {
    "low": 0.5,
    "high": 2.5
  }
}

random_choices

Choose k items from a population with replacement, optionally weighted.

Parameters:

• population (list): List of items to choose from
• k (int, optional): Number of items to choose (default: 1)
• weights (list, optional): Weights for each item (default: equal weights)

Example:

{
  "name": "random_choices",
  "arguments": {
    "population": ["red", "blue", "green", "yellow"],
    "k": 2,
    "weights": [0.4, 0.3, 0.2, 0.1]
  }
}

random_shuffle

Return a new list with items in random order.

Parameters:

• items (list): List of items to shuffle

Example:

{
  "name": "random_shuffle",
  "arguments": {
    "items": [1, 2, 3, 4, 5]
  }
}

random_sample

Choose k unique items from population without replacement.

Parameters:

• population (list): List of items to choose from
• k (int): Number of items to choose

Example:

{
  "name": "random_sample",
  "arguments": {
    "population": ["a", "b", "c", "d", "e"],
    "k": 2
  }
}

secure_token_hex

Generate a cryptographically secure random hex token.

Parameters:

• nbytes (int, optional): Number of random bytes (default: 32)

Example:

{
  "name": "secure_token_hex",
  "arguments": {
    "nbytes": 16
  }
}

secure_random_int

Generate a cryptographically secure random integer below upper_bound.

Parameters:

• upper_bound (int): Upper bound (exclusive)

Example:

{
  "name": "secure_random_int",
  "arguments": {
    "upper_bound": 1000
  }
}

Security Considerations

This package provides both standard pseudorandom functions (suitable for simulations, games, etc.) and cryptographically secure functions (suitable for tokens, keys, etc.):

• Standard functions (random_int, random_float, random_choices, random_shuffle): Use Python's random module - fast but not cryptographically secure
• Secure functions (secure_token_hex, secure_random_int): Use Python's secrets module - slower but cryptographically secure

Development

Prerequisites

• Python 3.10+
• uv package manager

Setup

# Clone the repository
git clone https://github.com/example/random-number-mcp
cd random-number-mcp

# Install dependencies
uv sync --dev

# Run tests
uv run pytest

# Run linting
uv run ruff check --fix
uv run ruff format

# Type checking
uv run mypy src/

MCP Client Config

{
  "mcpServers": {
    "random-number-dev": {
      "command": "uv",
      "args": [
        "--directory",
        "<path_to_your_repo>/random-number-mcp",
        "run",
        "random-number-mcp"
      ]
    }
  }
}

Note: Replace <path_to_your_repo>/random-number-mcp with the absolute path to your cloned repository.

Building

# Build package
uv build

# Test installation
uv run --with dist/*.whl random-number-mcp

Release Checklist

1. Update Version:

   • Increment the version number in pyproject.toml, src/random_number_mcp/__init__.py, and server.json.

2. Update Changelog:

   • Add a new entry in CHANGELOG.md for the release.

     • Draft notes with coding agent using git diff context.

     Update the @CHANGELOG.md for the latest release.
     List all significant changes, bug fixes, and new features.
     Here's the git diff:
     [GIT_DIFF]
     

   • Commit along with any other pending changes.

3. Create GitHub Release:

   • Draft a new release on the GitHub UI.
     • Tag release using UI.
   • The GitHub workflow will automatically build and publish the package to PyPI.

Testing with MCP Inspector

For exploring and/or developing this server, use the MCP Inspector npm utility:

# Install MCP Inspector
npm install -g @modelcontextprotocol/inspector

# Run local development server with the inspector
npx @modelcontextprotocol/inspector uv run random-number-mcp

# Run PyPI production server with the inspector
npx @modelcontextprotocol/inspector uvx random-number-mcp

MCP Registry

mcp-name: io.github.zazencodes/random-number-mcp