Check and manage feature flags in Unleash

Unleash MCP Server

A Model Context Protocol (MCP) server implementation that integrates with Unleash Feature Toggle system.

Overview

This project provides a bridge between LLM applications and Unleash feature flag system using the Model Context Protocol (MCP). It allows AI applications to:

1. Check feature flag status from Unleash
2. Expose feature flag information to LLMs
3. Create feature flag
4. Update feature flag
5. List all projects

Table of Contents

• Requirements
• Installation
• Architecture
• Configuration
• Development
• Contributing
• License

Requirements

• Node.js (v18 or higher)
• TypeScript (v5.0 or higher)
• Access to an Unleash server instance

Installation

# Install dependencies
npm i

Architecture

The Unleash MCP Server acts as a bridge between LLM applications and the Unleash feature flag system:

+----------------+      +-------------------+      +----------------+
|                |      |                   |      |                |
|  LLM App       | <--> |  Unleash MCP      | <--> |  Unleash API   |
|  (MCP Client)  |      |  Server           |      |  Server        |
|                |      |                   |      |                |
+----------------+      +-------------------+      +----------------+

Development

Project Structure

unleash-mcp-server/
├── src/
│   ├── index.ts              # Main entry point
│   ├── server.ts             # Server implementation
│   ├── config.ts             # Configuration handling
│   ├── transport/            # MCP transport implementations
│   │   ├── http.ts           # HTTP/SSE transport
│   │   └── stdio.ts          # STDIO transport
│   ├── unleash/              # Unleash API client implementations
│   │   ├── unleash-client.ts # Main Unleash client
│   │   ├── get-feature-flag.ts
│   │   └── get-all-projects.ts
│   ├── resources/            # MCP resource implementations
│   │   ├── flags.ts          # Feature flag resources
│   │   └── projects.ts       # Project resources
│   ├── tools/                # MCP tool implementations
│   │   ├── get-flag.ts       # Get feature flag tool
│   │   └── get-projects.ts   # Get projects tool
│   └── prompts/              # MCP prompt implementations
│       ├── flag-check.ts     # Check single flag
│       └── batch-flag-check.ts # Check multiple flags
├── tests/                    # Tests
└── package.json              # Project configuration

Coding Standards

• Naming Conventions:

  • Files: Use kebab-case.ts (e.g., feature-flag.ts)
  • Classes: Use PascalCase (e.g., UnleashClient)
  • Functions/Methods: Use camelCase (e.g., getFlagStatus)
  • Interfaces/Types: Use PascalCase (e.g., FeatureFlagConfig)

• Imports:

  • Always include .js extension when importing local files
  • Follow import ordering: Node.js built-ins → External dependencies → Local imports
  • Use named exports over default exports

• Documentation:

  • Use JSDoc comments for public functions, classes, and interfaces
  • Document complex logic with inline comments

Building

# Compile TypeScript
npm run build

# Run the server
npm start

Testing

# Run tests
npm test

Inspecting

# MCP stdio inspect
npm run build
npx @modelcontextprotocol/inspector node dist/index.js

# MCP sse inspect
npm start
npx @modelcontextprotocol/inspector

How to use

For Claude or Cursor config:

{
  "mcpServers": {
    "unleash": {
      "command": "npx",
      "args": [
        "-y",
        "unleash-mcp"
      ],
      "env": {
        "UNLEASH_URL": "YOUR_UNLEASH_END_POINT",
        "UNLEASH_API_TOKEN": "YOUR_UNLEASH_API_TOKEN",
        "MCP_TRANSPORT": "stdio",
        "MCP_HTTP_PORT": 3001
      }
    }
  }
}