Langfuse MCP (Model Context Protocol)
About
A Model Context Protocol (MCP) server for Langfuse, enabling AI agents to query Langfuse trace data for enhanced debugging and observability
Details
- Author
- avivsinai
- GitHub stars
- 99
- Downloads
- 711
- Categories
- Other, Developer Tools
Jump to
- 48 tools covering traces, observations, sessions, exceptions, prompts, datasets, annotation queues, scores, metrics, and schema.
- Selective tool loading via --tools flag to reduce token overhead.
- Read‑only mode (--read-only) disables all write operations.
- Default output mode (--default-output-mode) for compact, full JSON string, or file output.
- Support for HTTP transport with per‑project credentials via Authorization header.
- Included agent skill with playbooks for trace debugging, exception triage, latency analysis, prompt management, and dataset work.
Setting up with Highlight
This MCP is not yet compatible with Highlight’s one-click setup. However, you can still use it with Highlight by following these steps:
- Download and install Highlight from highlightai.com/download
- Navigate to the plugins tab and select "Add Custom Plugin"
-
Configure the plugin with the settings below
Plugin Name
Langfuse MCP (Model Context Protocol)Command (node, npx, python, etc.)Please refer to the README for specific instructions on how to obtain API keys or other required environment variables.
- Enable "Start Automatically" if you want the plugin to start when Highlight launches
From the repository
Install via uvx langfuse-mcp with Python 3.10+ and the uv runtime. Set environment variables LANGFUSE_PUBLIC_KEY, LANGFUSE_SECRET_KEY, and LANGFUSE_HOST (defaults to Langfuse Cloud). Add the server to an MCP client (Claude Code, Codex, Cursor) using the provided configuration commands or JSON files. Start the MCP client, then invoke tools directly or use the included agent skill for ready‑made debugging playbooks.
listTraces
List Langfuse traces with filters. Returns summary metadata (use getTrace for the full observation tree).
getTrace
Fetch a single trace by id including all nested observations.
listObservations
List observations (spans, generations, events) with filters.
getObservation
Fetch a single observation by id.
listSessions
List sessions within a time range.
getSession
Fetch a session by id, including its traces.
listScores
List scores with filters.
getScore
Fetch a single score by id.
listScoreConfigs
List score configurations (definitions for score names, ranges, and categories).
getScoreConfig
Fetch a single score configuration by id.
listPrompts
List prompt definitions tracked in Langfuse.
getPrompt
Fetch a prompt by name. Optionally pin to a specific version or label (e.g. 'production').
listDatasets
List datasets configured in Langfuse.
getDataset
Fetch metadata for a dataset by its name.
listDatasetItems
List items in a dataset (inputs / expected outputs / metadata).
getDatasetItem
Fetch a single dataset item by id.
listDatasetRuns
List runs (evaluation rounds) for a dataset.
getDatasetRun
Fetch a specific dataset run by name.
getMetrics
Run a metrics query (counts, latency, cost, token usage). Pass a JSON query string per the Langfuse metrics API.
getDailyMetrics
Fetch daily aggregated usage / cost / count metrics for traces and observations.
listModels
List models known to Langfuse (for cost / token attribution).
getModel
Fetch a single model definition by id.
listProjects
List projects accessible to the current API key (typically a single project).
listComments
List comments attached to traces, observations, sessions, or prompts.
getComment
Fetch a single comment by id.
getMedia
Fetch metadata for a media attachment (image, audio, file) by id.
getHealth
Pings the Langfuse public health endpoint. Useful to validate credentials and connectivity.
Claude Desktop / Cursor
Paste into your MCP client config file to install this server.
{
"mcpServers": {
"langfuse mcp (model context protocol)": {
"langfuse-mcp": {
"command": "npx",
"args": [
"skills",
"add",
"avivsinai/langfuse-mcp",
"-g",
"-y"
]
}
}
}
}
McpServers
{
"langfuse-mcp": {
"command": "npx",
"args": [
"skills",
"add",
"avivsinai/langfuse-mcp",
"-g",
"-y"
]
}
}
Langfuse MCP Server
Agent-facing Model Context Protocol server and skill for Langfuse observability.
Use langfuse-mcp from Claude Code, Codex, Cursor, or any MCP client to query traces, inspect generations, debug exceptions, analyze sessions, manage prompts, browse datasets, and understand what your AI agents did in production.
What You Can Do
- Debug failing agent runs from Langfuse traces and observations.
- Find exceptions, slow generations, high-latency spans, and affected users.
- Inspect sessions and user journeys without leaving your agent workflow.
- Manage prompt versions, labels, datasets, annotation queues, and scores.
- Install the included langfuse agent skill for ready-made debugging playbooks.
Project Links
- Quick Start
- Agent Skill
- Tools
- Selective Tool Loading
- Read-Only Mode
- Other Clients
Why langfuse-mcp?
Langfuse is where your traces live. langfuse-mcp makes that telemetry directly usable by agents that need to answer questions like "what failed?", "why was this slow?", "which prompt version ran?", or "what happened in this user's session?"
Positioning relative to the native Langfuse MCP (as of June 2026):
| | langfuse-mcp | Native Langfuse MCP |
|-|--------------|---------------------|
| Primary fit | Local, debugging-first MCP server + agent skill | Hosted, zero-install endpoint backed by Langfuse |
| Deployment | Local stdio or HTTP, via the Langfuse Python SDK | Native streamable HTTP at /api/public/mcp |
| Trace / session / exception tools | First-class | Observation/API-oriented access |
| Route-decision tools | Yes | No |
| Token & output control | Compact summaries, truncation, file-dump mode, tool-group gating | Depends on the hosted tool response + client |
| Metrics & dataset runs | Yes | Yes |
| Prompt, dataset, queue & score reads | Yes | Yes |
| Score writes, comments, models, media | Not yet | Yes |
This project does not mirror every native Langfuse MCP tool. It focuses on agent debugging ergonomics — compact trace inspection, exception triage, session analysis, routing-decision workflows, local tool-group gating, and an included skill with ready-made investigation playbooks. Use the native MCP for the broad hosted API surface; use langfuse-mcp as a local, token-disciplined layer.
Quick Start
Requires uv (for uvx) and Python 3.10 or newer. CI verifies Python 3.10 through 3.14.
Get credentials from Langfuse Cloud → Settings → API Keys. If self-hosted, use your instance URL for LANGFUSE_HOST.
```bash
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