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mcp-server-langfuse

MCP.Pizza Chef: langfuse

Two tools do all the work: list the prompts stored in your Langfuse account, and fetch one by name with its variables already filled in. Nothing here can create, edit or delete a prompt, despite the project describing itself as prompt management, and only prompts marked as production ever appear. You need a Langfuse account and its pair of keys, and you have to build the project yourself, because it was never released for a one-line install.

Unmaintained · no commits since February 2025; no successor named
Coding
Writing

Use This MCP server To

Pull a prompt my team wrote into my current chat See which prompts our Langfuse account holds Fill a prompt template with today's values Reuse a team-approved prompt instead of retyping it

README

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):

langfuse-prompts-mcp-server-1080.mp4

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": ["<absolute-path>/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: 
    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) if you have any suggestions or feedback.

mcp-server-langfuse FAQ

What sign-in details does it need?
A Langfuse account with two keys, one public and one secret, plus the web address of your Langfuse instance. The free hosted tier is enough, or point it at your own installation.
Can it save or change my prompts?
No. It only reads, whatever the project description implies. Writing and editing still happens inside Langfuse itself.
Why are some of my prompts missing?
Only prompts labelled production in Langfuse are returned. Drafts and any other label are invisible to it.
How hard is setup?
Developer level. There is no published package, so you clone the code, install it, run a build step, and point your config at the built file.
Which apps does it work in?
Claude Desktop and Cursor are the documented ones, and any app that can run a local server command will work.
Can I use this to reuse my team's approved prompts?
Yes, that is exactly its purpose. One tool lists what is available and the other returns a chosen prompt with your values substituted in.
Is it still maintained?
No. The last change landed in February 2025, about eighteen months ago, and the known rough edges it lists were never fixed. It is not marked archived and it names no successor.