Langfuse MCP server for AI agents and assistants

Securely connect your AI agents and chatbots (Claude, ChatGPT, Cursor, etc) with Langfuse MCP or direct API to inspect traces, review evals, manage prompts, and analyze metrics through natural language.

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Api Key

Langfuse is an open source LLM engineering platform for traces, evals, prompt management, and metrics. It helps teams debug, monitor, and improve LLM applications with clear observability data.

10 Tools

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TOOL ROUTER PLAYGROUND
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TOOLS

Supported Tools

Every Langfuse action and event your agent gets out of the box.

Create Score

Attach an evaluation score to exactly one Langfuse trace, session, or dataset run, optionally narrowing a trace score to an observation.

Get Prompt

Retrieve a Langfuse text or chat prompt by name, deployment label, or exact version, with optional dependency resolution.

List Annotation Queues

List annotation queues configured for human evaluation in the connected Langfuse project.

List Dataset Items

List dataset items, optionally scoped to a dataset, source trace or observation, or historical dataset version.

List Datasets

List datasets available to the connected Langfuse project.

List Experiments

List Langfuse experiments active in a required time range, optionally including metadata and directly attached scores.

List Models

List Langfuse-managed and project-custom model pricing definitions used for usage and cost calculation.

List Observations

Search Langfuse observations such as generations, spans, events, agents, and tool calls, selecting only the field groups needed.

List Scores

Search numeric, boolean, categorical, text, and correction scores with subject and annotation context.

Query Metrics

Run an aggregate Langfuse metrics query over observations or numeric, boolean, or categorical scores.

SETUP GUIDE

Connect Langfuse MCP Tool with your Agent

1

Install Composio

typescript
npm install @composio/core ai @ai-sdk/mcp @ai-sdk/openai
Install the Composio SDK and your agent framework
2

Create a session with MCP enabled

typescript
import { Composio } from "@composio/core";

const composio = new Composio();
const { mcp } = await composio.create("your-user-id", {
  toolkits: ["langfuse"],
  mcp: true,
});
Create a session scoped to Langfuse and read its MCP URL and headers
3

Connect your agent to the MCP server

typescript
import { createMCPClient } from "@ai-sdk/mcp";
import { openai } from "@ai-sdk/openai";
import { generateText, stepCountIs } from "ai";

const client = await createMCPClient({
  transport: { type: "http", url: mcp.url, headers: mcp.headers },
});

const { text } = await generateText({
  model: openai("gpt-5.6-sol"),
  tools: await client.tools(),
  prompt: "List recent Langfuse traces with errors and summarize common failure patterns",
  stopWhen: stepCountIs(10),
});

console.log(text);
await client.close();
Pass the session's MCP URL and headers to your agent and run a Langfuse request
SETUP GUIDE

Connect Langfuse API Tool with your Agent

1

Install Composio

typescript
npm install @composio/core @composio/openai openai
Install the Composio SDK, the OpenAI provider, and the OpenAI SDK
2

Create a Composio session

typescript
import OpenAI from "openai";
import { Composio } from "@composio/core";
import { OpenAIResponsesProvider } from "@composio/openai";

const composio = new Composio({ provider: new OpenAIResponsesProvider() });
const client = new OpenAI();

const session = await composio.create("your-user-id", { toolkits: ["langfuse"] });
const tools = await session.tools();
Initialize Composio with the OpenAI Responses provider and create a session scoped to Langfuse
3

Run Langfuse tools with your agent

typescript
let response = await client.responses.create({
  model: "gpt-5.6-sol",
  tools,
  input: [{ role: "user", content: "List recent Langfuse traces with errors and summarize common failure patterns" }],
});

while (response.output.some((o) => o.type === "function_call")) {
  const outputs = await composio.provider.handleToolCalls(session, response.output);
  response = await client.responses.create({
    model: "gpt-5.6-sol",
    tools,
    previous_response_id: response.id,
    input: outputs,
  });
}

console.log(response.output_text);
Send a request, execute the Langfuse tool calls through the session, and print the final answer

Why Use Composio?

AI Native Langfuse Integration

  • Supports both Langfuse MCP and direct API based integrations
  • Structured, LLM-friendly schemas for reliable trace, eval, prompt, and metric workflows
  • Rich coverage for reading, writing, and querying your Langfuse observability data

Managed Auth

  • Secure API key handling so you don't have to hard-code Langfuse credentials
  • Central place to manage, scope, and revoke Langfuse access
  • Per user and per environment credentials for safer agent deployments

Agent Optimized Design

  • Tools are tuned for AI agents, so they can work with Langfuse traces and metrics more reliably
  • Clear execution logs show what your agent ran, when it ran, and on whose behalf
  • Less glue code, fewer brittle integrations, and faster debugging loops

Enterprise Grade Security

  • Fine-grained RBAC so you control which agents and users can access Langfuse
  • Scoped, least privilege access to Langfuse resources
  • Full audit trail of agent actions to support review, security checks, and compliance
FAQ

Frequently asked questions

Yes, Langfuse requires you to configure your own API key. Once set up, Composio handles secure credential storage and API request handling for you.

Yes! Composio's Tool Router enables agents to use multiple toolkits. Learn more.

Yes. Composio is SOC 2 Type II compliant and is built to keep your Langfuse connection and credentials secure. OAuth tokens and API keys are encrypted, and sensitive customer data is protected at rest and in transit.

Composio also undergoes independent security testing and continuously monitors its systems for security threats. You can review the latest reports and policies in the Composio Trust Center.

Composio maintains and updates all toolkit integrations automatically, so your agents always work with the latest API versions.

Create the key in your Langfuse account settings, then paste it once on Composio's connection page. Composio stores it encrypted and uses it only for the Langfuse actions your agent runs. Nobody else in your workspace can read it, and you can revoke it inside Langfuse at any time.

When you connect a Langfuse account through Composio, every action runs under that account, so anything the agent creates, sends, or changes shows up in Langfuse as done by you. Keep an approval step in your prompt for actions with side effects, such as sending or deleting, and have the agent draft first.

Whatever the credentials you connect allow inside Langfuse. If Langfuse lets you scope a key to specific permissions, create a scoped one so the agent can only do what you intend. You can revoke the key inside Langfuse at any time.

Yes. Composio supports multiple connected accounts for the same app, and that works in Claude, ChatGPT, or any other assistant you connect through Composio. Give each Langfuse connection a name such as work or personal, and the assistant uses the one you mention in the request. Each account keeps its own credentials and nothing is merged.

The connection stops working the moment Langfuse rejects the old key. Create a new key in Langfuse and reconnect the account from the Composio dashboard or by asking your agent to reconnect Langfuse. Nothing else changes.

Composio's free Hobby plan includes 100,000 tool calls per month with no credit card, which covers most personal Langfuse use. Paid plans add higher limits and team features. Your Langfuse plan and its API limits still apply as usual.

Built-in connectors usually give one AI access to a limited set of apps. Many people use Composio because it lets their AI connect to more apps than it normally supports, or connect to multiple accounts for the same app (e.g. connect Claude to multiple Langfuse accounts).

With Composio, you connect Langfuse once and then use it across different AI assistants without setting it up separately in each one. Connect your apps to Composio once, then connect Composio to whichever AI you use, whether that's Claude, ChatGPT, Hermes, or your own custom assistant.

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