What is Langfuse Prompt Management?

Langfuse Prompt Management is an open-source tool for collaborative editing, versioning, evaluating, and releasing prompts. It provides an MCP (Model Context Protocol) server that allows users to access and manage their Langfuse prompts through the Model Context Protocol, enabling seamless integration with other MCP-compatible tools.

How to use Langfuse Prompt Management?

1. Installation: Run npm install followed by npm run build to set up the server.
2. Configuration: Configure the MCP server in platforms like Claude Desktop or Cursor by specifying the command and environment variables (Langfuse keys).
3. Usage: Access prompts via MCP endpoints (prompts/list, prompts/get) or use tool endpoints (get-prompts, get-prompt).

Key features of Langfuse Prompt Management?

• MCP Prompt Endpoints: List and retrieve prompts with pagination and variable handling.
• Tool Compatibility: Provides alternative tool endpoints for platforms without MCP support.
• Integration: Works with Claude Desktop and Cursor, allowing prompt management within AI workflows.

Use cases of Langfuse Prompt Management?

1. Collaborative Prompt Development: Teams can collaboratively build and version prompt templates.
2. AI Workflow Integration: Enhance AI applications by dynamically retrieving managed prompts.
3. Prompt Evaluation: Track and evaluate prompt performance through Langfuse’s analytics.

FAQ from Langfuse Prompt Management?

• What is the difference between MCP Prompt endpoints and tool endpoints?

  MCP endpoints (prompts/list, prompts/get) follow the Model Context Protocol specification, while tools (get-prompts, get-prompt) are fallback endpoints for non-MCP compatible clients.

• Are there any limitations?

  Yes, it currently only supports prompts with a production label in Langfuse and assumes all arguments are optional. List operations may be inefficient due to background prompt fetching.

• How can I contribute?

  Contributions are welcome! Open an issue or PR on GitHub (repo).

Langfuse Prompt Management MCP Server

Model Context Protocol (MCP) Server for Langfuse Prompt Management. This server allows you to access and manage your Langfuse prompts through the Model Context Protocol.

Demo

Quick demo of Langfuse Prompts MCP in Claude Desktop (unmute for voice-over explanations):

https://github.com/user-attachments/assets/61da79af-07c2-4f69-b28c-ca7c6e606405

Features

MCP Prompt

This server implements the MCP Prompts specification for prompt discovery and retrieval.

• prompts/list: List all available prompts

  • Optional cursor-based pagination
  • Returns prompt names and their required arguments, limitation: all arguments are assumed to be optional and do not include descriptions as variables do not have specification in Langfuse
  • Includes next cursor for pagination if there's more than 1 page of prompts

• prompts/get: Get a specific prompt

  • Transforms Langfuse prompts (text and chat) into MCP prompt objects
  • Compiles prompt with provided variables

Tools

To increase compatibility with other MCP clients that do not support the prompt capability, the server also exports tools that replicate the functionality of the MCP Prompts.

• get-prompts: List available prompts

  • Optional cursor parameter for pagination
  • Returns a list of prompts with their arguments

• get-prompt: Retrieve and compile a specific prompt

  • Required name parameter: Name of the prompt to retrieve
  • Optional arguments parameter: JSON object with prompt variables

Development

npm install

# build current file
npm run build

# test in mcp inspector
npx @modelcontextprotocol/inspector node ./build/index.js

Usage

Step 1: Build

npm install
npm run build

Step 2: Add the server to your MCP servers:

Claude Desktop

Configure Claude for Desktop by editing claude_desktop_config.json

{
  "mcpServers": {
    "langfuse": {
      "command": "node",
      "args": ["/build/index.js"], "env": { "LANGFUSE_PUBLIC_KEY": "your-public-key", "LANGFUSE_SECRET_KEY": "your-secret-key", "LANGFUSE_BASEURL": "https://cloud.langfuse.com" } } } } ``` Make sure to replace the environment variables with your actual Langfuse API keys. The server will now be available to use in Claude Desktop. #### Cursor Add new server to Cursor: - Name: `Langfuse Prompts` - Type: `command` - Command: ```bash LANGFUSE_PUBLIC_KEY="your-public-key" LANGFUSE_SECRET_KEY="your-secret-key" LANGFUSE_BASEURL="https://cloud.langfuse.com" node absolute-path/build/index.js ``` ## Limitations The MCP Server is a work in progress and has some limitations: - Only prompts with a `production` label in Langfuse are returned - All arguments are assumed to be optional and do not include descriptions as variables do not have specification in Langfuse - List operations require fetching each prompt individually in the background to extract the arguments, this works but is not efficient Contributions are welcome! Please open an issue or a PR ([repo](https://github.com/langfuse/mcp-server-langfuse)) if you have any suggestions or feedback.