OpenFeature MCP Cloudflare Worker

Warning

This project is in active development and intended for testing only. APIs, prompts, and behavior may change without notice. Do not use in production.

A simplified Model Context Protocol (MCP) server running on Cloudflare Workers that provides OpenFeature SDK installation guidance.

Features

• No Authentication Required: Simplified implementation without OAuth or user management
• OpenFeature SDK Installation Guides: Fetch installation prompts for various OpenFeature SDKs
• MCP Protocol Support: Supports both SSE and JSON-RPC transports
• Cloudflare Workers: Serverless deployment with global edge distribution

Configure your AI client

Use the hosted endpoint for this OpenFeature MCP worker: https://mcp-openfeature.devcycle.com/mcp

No authentication is required for this MCP.

Cursor

Add to ~/.cursor/mcp_settings.json:

{
  "mcpServers": {
    "OpenFeature": {
      "url": "https://mcp-openfeature.devcycle.com/mcp"
    }
  }
}

VS Code (Continue)

Add to .continue/config.json:

{
  "mcpServers": {
    "OpenFeature": {
      "url": "https://mcp-openfeature.devcycle.com/mcp"
    }
  }
}

Claude Code (CLI)

claude mcp add --transport http openfeature https://mcp-openfeature.devcycle.com/mcp

Then manage the connection in the CLI with /mcp.

Claude Desktop

Edit your Claude Desktop config and add:

{
  "mcpServers": {
    "openfeature": {
      "command": "npx",
      "args": ["mcp-remote", "https://mcp-openfeature.devcycle.com/mcp"]
    }
  }
}

Restart Claude Desktop after saving.

Windsurf

In the "Manage MCP servers" raw config, add:

{
  "mcpServers": {
    "OpenFeature": {
      "serverUrl": "https://mcp-openfeature.devcycle.com/mcp"
    }
  }
}

Reference installation patterns adapted from the DevCycle MCP getting started guide DevCycle MCP Getting Started.

Available Tools

install_openfeature_sdk

Fetches and returns OpenFeature SDK install prompt Markdown for a given guide from the bundled prompts.

Parameters:

• guide (string enum): One of the supported guides listed below

Supported Guides (bundled):

• android
• dotnet
• go
• ios
• java
• javascript
• nestjs
• nodejs
• php
• python
• react
• ruby

Endpoints

• /mcp - MCP JSON-RPC transport endpoint
• /sse - MCP Server-Sent Events transport endpoint
• /health - Health check endpoint
• /info - Service information endpoint (includes available guides)
• / - Redirects to OpenFeature docs reference intro

Development

Prerequisites

• Node.js 18+
• Yarn (using regular node_modules, not PnP)
• Wrangler CLI

Setup

1. Install dependencies:

   yarn install

2. Add or edit install guides in the prompts/ folder (Markdown). These are bundled at build time.

3. Build prompts bundle:

   yarn build-prompts

4. Run locally:

   yarn dev

5. Build for production:

   yarn build

Deployment

Deploy to Cloudflare Workers:

yarn deploy

Usage

The worker exposes MCP transport endpoints and simple health/info endpoints.

Examples

1. Health:

   curl http://localhost:8787/health

2. Info:

   curl http://localhost:8787/info

3. MCP over HTTP (JSON-RPC) or SSE: Point your MCP-compatible client to /mcp (JSON-RPC) or /sse (SSE). The tool name is install_openfeature_sdk and requires an input object like { "guide": "react" }.

Architecture

This is a simplified version of the DevCycle MCP worker, with all authentication and project management features removed. It focuses solely on providing OpenFeature SDK installation guidance through MCP tool calls.