Langfuse

Name: Langfuse
Author: pulsemcp

by pulsemcpversion 0.1.3i★ 81 (Stars for the whole repo)iRuns on your computer

Registry namecom.pulsemcp/langfuse

How to install

What it does

MCP server for Langfuse LLM observability — trace and observation analysis.

Connects Runs on your computer
Account or key Needs LANGFUSE_SECRET_KEY, LANGFUSE_PUBLIC_KEY
Category Search & AI memory

Install

Pick the AI app you use, then copy the settings.

Passed 3/3 checks · Runs on your computer · ✓ Commands checked Nov 13, 2026

First: which AI do you use?

ClaudeWeb · app · phoneChatGPTWebClaude CodeTerminalCursorCode editorVS CodeCode editorOtherOther apps

Pick your app and the steps appear below.

Works with Claude, with some setup first

You need a Langfuse key (create it on the maker’s site) · Install Node.js on your computer first (one time) · Only the Claude desktop app (Windows or Mac), not the web or phone

Install Node.js
One time only; it works for every server that needs Node.js
Open the Node.js download page ↗
Done
Sign up and create a Langfuse key
Open the maker’s site, sign up and create an API key for the next step. Check the maker’s site for pricing and free plans.
How to get a key is in the maker’s README below
Done
Open the Claude desktop app’s settings file
SettingsDeveloperEdit Config
Done

Paste these settings and save the file

{
  "mcpServers": {
    "langfuse": {
      "command": "npx",
      "args": [
        "-y",
        "langfuse-observability-mcp-server"
      ],
      "env": {
        "LANGFUSE_SECRET_KEY": "your-value",
        "LANGFUSE_PUBLIC_KEY": "your-value",
        "LANGFUSE_BASE_URL": "your-value"
      }
    }
  }
}

Paste the key only into the app’s field, never into a chat or to anyone

Done

Quit Claude and open it again
Done
Try it
Use Langfuse and tell me what you can do for me, then show me one thing
✓ If Claude says it is using Langfuse or shows a Langfuse tool in the answer, you are connected

Menu names checked against Anthropic’s help page on Nov 11, 2026 · your screen may differ slightly by app version

ChatGPT cannot connect Langfuse yet

Langfuse runs on your computer, but ChatGPT can only connect servers that run on the web

What you can do instead

A · Use an app that can connect Langfuse

Steps for Claude →You need a Langfuse key (create it on the maker’s site) · Install Node.js on your computer first (one time) · Only the Claude desktop app (Windows or Mac), not the web or phone
Steps for Claude Code →You need a Langfuse key (create it on the maker’s site) · Install Node.js on your computer first (one time)
Steps for Cursor →You need a Langfuse key (create it on the maker’s site) · Install Node.js on your computer first (one time)
Steps for VS Code →You need a Langfuse key (create it on the maker’s site) · Install Node.js on your computer first (one time)

B · Others in Search & AI memory that work with ChatGPT

Picked from the most used in the same category, only ones that connect by address with no key

Context7✓ ChatGPT
AIHOT✓ ChatGPT
Sui Knowledge Base (kapa.ai)✓ ChatGPT

Works with Claude Code, with some setup first

You need a Langfuse key (create it on the maker’s site) · Install Node.js on your computer first (one time)

Install Node.js
One time only; it works for every server that needs Node.js
Open the Node.js download page ↗
Done
Sign up and create a Langfuse key
Open the maker’s site, sign up and create an API key for the next step. Check the maker’s site for pricing and free plans.
How to get a key is in the maker’s README below
Done
Open Terminal
Mac: press Command+Space and type Terminal · Windows: open PowerShell
Done

Paste this command and press Enter

claude mcp add --scope user langfuse --env LANGFUSE_SECRET_KEY=your-value --env LANGFUSE_PUBLIC_KEY=your-value --env LANGFUSE_BASE_URL=your-value -- npx -y langfuse-observability-mcp-server

Replace “your-value” with your key before pressing Enter

Paste the key only into the app’s field, never into a chat or to anyone

Done

Type /mcp in Claude Code
You should see Langfuse listed as connected
Done
Try it
Use Langfuse and tell me what you can do for me, then show me one thing
✓ If Claude Code says it is using Langfuse or shows a Langfuse tool in the answer, you are connected

Menu names checked against Anthropic’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Works with Cursor, with some setup first

You need a Langfuse key (create it on the maker’s site) · Install Node.js on your computer first (one time)

Install Node.js
One time only; it works for every server that needs Node.js
Open the Node.js download page ↗
Done
Sign up and create a Langfuse key
Open the maker’s site, sign up and create an API key for the next step. Check the maker’s site for pricing and free plans.
How to get a key is in the maker’s README below
Done
Click this button to open Cursor
Open in Cursor
Cursor asks you to confirm; click Install
Done
Fill in your key
In the Langfuse settings, LANGFUSE_SECRET_KEY, LANGFUSE_PUBLIC_KEY, LANGFUSE_BASE_URL is empty; add your key and save
Paste the key only into the app’s field, never into a chat or to anyone
Done
Open the AI chat in Cursor in Agent mode
Done
Try it
Use Langfuse and tell me what you can do for me, then show me one thing
✓ If Cursor says it is using Langfuse or shows a Langfuse tool in the answer, you are connected

Menu names checked against Cursor’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Works with VS Code, with some setup first

You need a Langfuse key (create it on the maker’s site) · Install Node.js on your computer first (one time)

Install Node.js
One time only; it works for every server that needs Node.js
Open the Node.js download page ↗
Done
Sign up and create a Langfuse key
Open the maker’s site, sign up and create an API key for the next step. Check the maker’s site for pricing and free plans.
How to get a key is in the maker’s README below
Done
Click this button to open VS Code
Open in VS Code
VS Code asks you to confirm; click Install
Done
Fill in your key
In the Langfuse settings, LANGFUSE_SECRET_KEY, LANGFUSE_PUBLIC_KEY, LANGFUSE_BASE_URL is empty; add your key and save
Paste the key only into the app’s field, never into a chat or to anyone
Done
Open the AI chat in VS Code in Agent mode
Done
Try it
Use Langfuse and tell me what you can do for me, then show me one thing
✓ If VS Code says it is using Langfuse or shows a Langfuse tool in the answer, you are connected

Menu names checked against VS Code’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Other apps that use MCP, such as Windsurf, Zed or Gemini CLI, each add servers differently. See how in the app list.

See every app that uses MCP →

JSON settings are under “For developers” below

Stuck? Ask people who use Langfuse💬 Discussion →

For developers: Terminal commands and JSON settings

Installed on your computer

Claude Code

claude mcp add --scope user langfuse --env LANGFUSE_SECRET_KEY=your-value --env LANGFUSE_PUBLIC_KEY=your-value --env LANGFUSE_BASE_URL=your-value -- npx -y langfuse-observability-mcp-server

Claude Desktop (claude_desktop_config.json)

{
  "mcpServers": {
    "langfuse": {
      "command": "npx",
      "args": [
        "-y",
        "langfuse-observability-mcp-server"
      ],
      "env": {
        "LANGFUSE_SECRET_KEY": "your-value",
        "LANGFUSE_PUBLIC_KEY": "your-value",
        "LANGFUSE_BASE_URL": "your-value"
      }
    }
  }
}

Cursor (~/.cursor/mcp.json)

{
  "mcpServers": {
    "langfuse": {
      "command": "npx",
      "args": [
        "-y",
        "langfuse-observability-mcp-server"
      ],
      "env": {
        "LANGFUSE_SECRET_KEY": "your-value",
        "LANGFUSE_PUBLIC_KEY": "your-value",
        "LANGFUSE_BASE_URL": "your-value"
      }
    }
  }
}

VS Code (mcp.json)

{
  "servers": {
    "langfuse": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "langfuse-observability-mcp-server"
      ],
      "env": {
        "LANGFUSE_SECRET_KEY": "your-value",
        "LANGFUSE_PUBLIC_KEY": "your-value",
        "LANGFUSE_BASE_URL": "your-value"
      }
    }
  }
}

Values you fill in

LANGFUSE_SECRET_KEY secret required env
Langfuse secret key for authentication.
LANGFUSE_PUBLIC_KEY secret required env
Langfuse public key for authentication.
LANGFUSE_BASE_URL env
Langfuse API base URL.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

At a glance

GitHub stars i: 81 (Stars for the whole repo)
This repo holds several MCP listings; its stars count once in rankings
Downloads per weeki: 167/wk
Verified domain: ✓ pulsemcp.com
Licence i: MIT
Connection: Runs on your computer
Transport: stdio
Latest versioni: 0.1.3
Categoryi: Search & AI memory
Published to registryi: Jun 17, 2026
Code last changedi: Oct 10, 2026
Maker: pulsemcp
Packages: npm: langfuse-observability-mcp-server
Repo: pulsemcp/mcp-servers
Registry status: Active

Which apps can use it

Based on how this server connects and on each app’s own docs, checked Nov 10, 2026.

Run on your computer in

Claude Goose LM Studio Msty Studio Cherry Studio Cursor VS Code + GitHub Copilot Visual Studio Windsurf (Devin Desktop)Zed Kiro Cline Continue JetBrains AI Assistant Claude Code Codex CLI Gemini CLI OpenCode nodecode Warp LibreChat Raycast

All apps, with pros and cons →

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 13, 2026

✓ Pass
Maker matches the repo
The registry name was verified against the domain pulsemcp.com (the registry checks domain ownership)
✓ Pass
Still maintained
Code last changed 34 days ago
✓ Pass
Has a licence
Uses MIT
– Not applicable
Endpoint responds
This one runs on your computer; there is no internet endpoint
– Not applicable
Sign-in with OAuth
Runs on your computer and uses local settings instead
… Not checked yet
No hidden instructions in tool descriptions
Runs on your computer; we can only read tool lists from internet endpoints

Discussion

Ask, share a tip or report that it does not work. Sorted by what people marked helpful.

No posts yet. Be the first to ask or share.

Posts here are written by users, not the PopNx team.

User reviews

No reviews yet

Compared with others in Search & AI memoryi

More stars than 0% of the other 6055 servers in this category
Published to the registry more recently than 16% of the other 6055 servers in this category
Basic checks equal to or better than 100% of the other 6055 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is Langfuse safe?

It passed 3 of 3 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

You need to fill in: LANGFUSE_SECRET_KEY, LANGFUSE_PUBLIC_KEY

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed 34 days ago, and the latest version (0.1.3) reached the registry 5 months ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Node.js on your computer.

What can I use instead?

In the same category: Context7, Codebase Memory, Ruflo

Others in the same category

Servers in the same category from other makers, sorted by stars.

Reading a card:↓ Downloads per weeki★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Context7

Feeds AI the latest docs for libraries and frameworks before it answers, so code it writes does not use outdated, removed functions.

by upstashWidely used↓ 1.2M/wk★ 64.7KUpdated yesterday

Computer or cloud

Install

Codebase Memory

Codebase knowledge graph for AI agents — 162 languages, sub-ms queries, 99% fewer tokens.

by DeusDataWidely used↓ 16.8K/wk★ 48.6KUpdated 27 days ago

Runs on your computer

Install

Ruflo

Agent teams, swarms, memory and hooks for Claude Code and Codex, served over MCP.

by ruvnetWidely used↓ 74.3K/wk★ 81.6K Stars for the whole repoUpdated today

Runs on your computer

Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

Langfuse MCP Server

MCP server for readonly analysis of Langfuse LLM traces and observations. Designed to help agents deeply inspect trace data, debug LLM pipelines, and analyze costs and latency.

Highlights

Browse and filter traces by name, user, session, tags, timestamps, and environment
Drill into full trace details including all nested observations and scores
List and filter observations by type (GENERATION, SPAN, EVENT), model, level, and more
Automatic truncation of large payloads (>1000 chars) to /tmp files with grep-friendly references
Read-only — no write operations, safe to use without risk of data modification

Capabilities

Tools

Tool	Description
`get_traces`	List traces with filtering and pagination. Returns minimal summary (no I/O fields).
`get_trace_detail`	Get full trace by ID including observations, scores, input/output, and metadata.
`get_observations`	List observations with filtering by traceId, type, level, etc. Returns minimal summary.
`get_observation`	Get full observation by ID including input, output, model parameters, usage, and cost details.

Resources

Resource	Description
`langfuse://config`	Server configuration and status (for debugging)

Large Payload Handling

Trace and observation data often contains very large input/output fields (full prompts, completions, etc.). This server automatically:

Truncates any string field longer than 1000 characters
Saves the full content to a /tmp/langfuse_*.txt file
Includes the file path in the truncated output

Agents can then use grep to search within these files for specific content without loading the entire payload into context.

Configuration

Environment Variables

Variable	Required	Description	Default
`LANGFUSE_SECRET_KEY`	Yes	Langfuse secret key (sk-lf-...)	-
`LANGFUSE_PUBLIC_KEY`	Yes	Langfuse public key (pk-lf-...)	-
`LANGFUSE_BASE_URL`	No	Langfuse API base URL	`https://cloud.langfuse.com`

Claude Desktop Configuration

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json

Windows: %APPDATA%\Claude\claude_desktop_config.json

"mcpServers": { "langfuse": { "command": "npx", "args": ["-y", "langfuse-observability-mcp-server"], "env": { "LANGFUSE_SECRET_KEY": "sk-lf-your-secret-key", "LANGFUSE_PUBLIC_KEY": "pk-lf-your-public-key", "LANGFUSE_BASE_URL": "https://us.cloud.langfuse.com" } } } }

Development

# Install dependencies

npm run install-all

Build

npm run build

Development mode

npm run dev

Run functional tests

npm test

Run integration tests

npm run test:integration

Run manual tests (requires .env with real credentials)

npm run test:manual

License

MIT

Langfuse

What it does

Install

Install Node.js

Sign up and create a Langfuse key

Open the Claude desktop app’s settings file

Paste these settings and save the file

Quit Claude and open it again

Try it

What you can do instead

Install Node.js

Sign up and create a Langfuse key

Open Terminal

Paste this command and press Enter

Type /mcp in Claude Code

Try it

Install Node.js

Sign up and create a Langfuse key

Click this button to open Cursor

Fill in your key

Open the AI chat in Cursor in Agent mode

Try it

Install Node.js

Sign up and create a Langfuse key

Click this button to open VS Code

Fill in your key

Open the AI chat in VS Code in Agent mode

Try it

Installed on your computer

Values you fill in

At a glance

Which apps can use it

Related guides

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Discussion

User reviews

Compared with others in Search & AI memoryi

Common questions

Others in the same category

Context7

Codebase Memory

Ruflo

README from the maker

Langfuse MCP Server

Highlights

Capabilities

Tools

Resources

Large Payload Handling

Configuration

Environment Variables

Claude Desktop Configuration

Development

Build

Development mode

Run functional tests

Run integration tests

Run manual tests (requires .env with real credentials)

License