MCP Server Langfuse

🚀 Model Context Protocol (MCP) Server - Langfuse Prompt Management

This server enables access and management of your Langfuse prompts via the Model Context Protocol.

🚀 Quick Start

The server implements the Model Context Protocol (MCP) of Langfuse Prompt Management, allowing you to access and manage your Langfuse prompts through the Model Context Protocol.

✨ Features

MCP Prompt Features

The server implements the MCP Prompt Specification for prompt discovery and retrieval.

• prompts/list: List all available prompts

  • Optional pagination cursor
  • Return prompt names and their required parameters. Limitation: All parameters are assumed to be optional and do not include descriptions (since variables in Langfuse have no descriptions).
  • Return the cursor for the next page if there are more prompt pages.

• prompts/get: Get a specific prompt

  • Convert Langfuse prompts (text and conversations) to MCP prompt objects.
  • Compile the prompt with the provided variables.

Tool Extension

To improve compatibility with other MCP clients that do not support prompt features, the server also exports tools to simulate prompt features.

• get-prompts: List available prompts

  • Optional cursor parameter for pagination
  • Return a list of prompts and their parameters

• get-prompt: Retrieve and compile a specific prompt

  • Required name parameter: The name of the prompt to retrieve
  • Optional arguments parameter: A JSON object containing prompt variables

📦 Installation

npm install

# Build the current files
npm run build

# Test in the MCP inspector
npx @modelcontextprotocol/inspector node ./build/index.js

💻 Usage Examples

Basic Usage

Step 1: Build the service

npm install
npm run build

Step 2: Add the server to your MCP server configuration

Configuration in Claude Desktop

Edit the claude_desktop_config.json file:

{
  "mcpServers": {
    "langfuse": {
      "command": "node",
      "args": ["<absolute-path>/build/index.js"],
      "env": {
        "LANGFUSE_PUBLIC_KEY": "your-public-key", // Replace with your public key
        "LANGFUSE_SECRET_KEY": "your-secret-key",  // Replace with your private key
        "LANGFUSE_BASEURL": "https://cloud.langfuse.com"
      }
    }
  }
}

Ensure that you replace the environment variables with your actual Langfuse API keys. After configuration, the server will be available in Claude Desktop.

Addition in Cursor

• Name: Langfuse Prompts
• Type: Command Line
• Command:

LANGFUSE_PUBLIC_KEY="your-public-key" LANGFUSE_SECRET_KEY="your-secret-key" LANGFUSE_BASEURL="https://cloud.langfuse.com" node absolute-path/build/index.js

🔧 Technical Details

The current MCP server is still in the development stage and has some limitations:

• Only prompts with the production tag in Langfuse will be returned.
• All parameters are assumed to be optional and do not include descriptions (since variables in Langfuse have no descriptions).
• List operations require fetching each prompt in the background to extract parameters, which is feasible but inefficient.

Contributions are welcome! If you have ideas for improvements or feedback, please submit issues or pull requests through the repository.