The Unleash MCP Server bridges LLM applications with the Unleash feature flag system via the Model Context Protocol, enabling comprehensive feature flag management:

Check and retrieve detailed information about feature flags
Create, update, and archive feature flags in projects
Enable or disable feature flags in specific environments
Add, update, delete, and reorder strategies for feature flags
Mark features as stale or not stale
Validate feature flag names for availability
List all feature flags, projects, environments, and feature types
Manage tags by adding or retrieving them
Perform batch operations like marking multiple features as stale
Modify existing flags using standard updates or JSON Patch

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:

Check feature flag status from Unleash
Expose feature flag information to LLMs
Create feature flag
Update feature flag
List all projects

Related MCP server: Memory Cache Server

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:

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 } } } }

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Support the Project

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License

This project is licensed under the MIT License - see the LICENSE file for details.

Unleash MCP (Feature Toggle)