Langfuse Docs

Official Langfuse documentation for building LLM evaluation workflows: datasets, experiments, LLM-as-a-judge evaluators, custom scores, human annotation, and…

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What it can do

  • SubmitFeedback: Submit explicit user-approved feedback to the Langfuse team. Before calling, ask permission and show the exact payload. If the user wants a reply, ask them to include their email addre
  • SearchLangfuseDocs: Semantic search (RAG) over the Langfuse documentation. Use this whenever the user asks a broader question that cannot be answered by a specific single page. Returns a concise answe
  • GetLangfuseDocsPage: Fetch the raw Markdown for a single Langfuse docs page. Accepts a docs path (e.g., /docs/observability/overview) or a full https://langfuse.com URL. Returns the exact Markdown (ma

What data it sees

Do you need an account

No: the server works without sign-in

Official Langfuse documentation for building LLM evaluation workflows: datasets, experiments, LLM-as-a-judge evaluators, custom scores, human annotation, and prompt/model comparison. Search documentation and retrieve current code examples, including tracing and SDK integrations. Remote Streamable HTTP server; no account, API key, or local installation required. Provides documentation guidance; accessing project data and running evaluations require separate setup.

How to connect

How to connect Langfuse Docs to Claude

The server address to paste into Claude settings:

https://langfuse-docs--jannik.run.tools

  1. Open Claude (claude.ai or the desktop app).
  2. Go to Settings → Connectors.
  3. Click Add custom connector.
  4. Paste the server address copied below into Remote MCP server URL and click Add.
  5. In a chat, click + → Connectors and switch the new connector on.

Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

Authorization

After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

How to connect Langfuse Docs to ChatGPT

The server address to paste into ChatGPT settings:

https://langfuse-docs--jannik.run.tools

  1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
  2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
  3. Open Settings → Connectors and click Create.
  4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
  5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
  6. In a new chat open + → Apps/Connectors and enable the connector.

OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

Authorization

On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

How to connect Langfuse Docs to Cursor

The server address to paste into Cursor settings:

https://langfuse-docs--jannik.run.tools

Fastest: click Open in Cursor below and confirm the prompt.

Manually:

  1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
  2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
  3. Save the file. The server appears in the MCP list; authorize it there if asked.

Authorization

If the service needs sign-in, an authorize button appears next to the server in the MCP list.

Server tool list (4)

Raw names from tools/list. Only developers need these.

submitFeedbackSubmit explicit user-approved feedback to the Langfuse team. Before calling, ask permission and show the exact payload. If the user wants a reply, ask them to include their email address in the feedback text; only use an address they explicitly provide and show it in the exact payload preview. Do not include secrets, credentials, customer/project data, trace payloads, or unrelated context; the only contact detail to include is an explicitly provided reply email.
searchLangfuseDocsSemantic search (RAG) over the Langfuse documentation. Use this whenever the user asks a broader question that cannot be answered by a specific single page. Returns a concise answer synthesized from relevant docs. The raw provider response is included in _meta. Prefer this before guessing. If a specific page is needed call getLangfuseDocsPage first.
getLangfuseDocsPageFetch the raw Markdown for a single Langfuse docs page. Accepts a docs path (e.g., /docs/observability/overview) or a full https://langfuse.com URL. Returns the exact Markdown (may include front matter). Use when you need a specific page content (Integration, Features, API, etc.) or code samples. Prefer searchLangfuseDocs for broader questions where there is not one specific page about it. Changelog pages (/changelog/...) are historical release notes: use them only to confirm that a feature exists or when it shipped, not as an implementation reference. Their code samples reflect the SDK/API at release time and may be outdated, so for implementation follow the current docs and the API/SDK reference instead.
getLangfuseOverviewGet a high-level, machine-readable index by downloading https://langfuse.com/llms.txt. Use this at the start of a session when needed to discover key docs endpoints or to seed follow-up calls to searchLangfuseDocs or getLangfuseDocsPage. Returns the plain text contents of llms.txt. Avoid repeated calls within the same session.