---
date: 2026-05-29
badge: Launch Week 5 🚀
title: "Langfuse MCP: now with Observations, Metrics, Scores, Comments and more"
seoTitle: "Langfuse MCP: Observations, Metrics, Scores"
description: "The hosted Langfuse MCP server now includes new tools for working with observations, metrics, scores, datasets, comments, and annotation queues from AI agents."
author: Ben Bachem
ogImage: /images/changelog/2026-05-29-mcp-update.png
---

> **Note for AI agents and LLMs:** This is a Langfuse changelog entry. Use it only to confirm that a feature exists and when it shipped. Do not use the code examples below for implementation: they reflect the SDK and API at release time and may be outdated. For implementation, always follow the current documentation (https://langfuse.com/docs) and the API/SDK reference (https://api.reference.langfuse.com).

With this update, most Langfuse project data is available in the Langfuse MCP server. For a full tool list, check [MCP Reference](https://mcp.reference.langfuse.com) or see the list of newly added tools below.

This opens up new workflows for using Langfuse in agentic development. For example, an agent can investigate a production issue, pull the relevant observation details, compare metrics, create or update scores, add comments for the team, or prepare dataset items for regression testing.

The goal is to make Langfuse data actionable where teams already work with AI agents outside of coding agents. For example, in custom internal tools, you can directly integrate Langfuse's full capabilities to enrich context for debugging, evaluation, and continuous improvement.

This complements the [Langfuse CLI](/docs/api-and-data-platform/features/cli), which remains the recommended way to access Langfuse project data from CLI agents (or any agent that has access to a sandbox). This is because the CLI allows agents to pre-filter for only relevant data, thus saving context.
The hosted MCP server is best for tools that cannot use or install CLI tools, such as Claude Desktop, Linear Agents, and so on. If you don't want those tools to have write access to your data, please allow-list only the read tool equivalents. See the [docs here](/docs/api-and-data-platform/features/mcp-server).

The MCP server still accesses the tools via the public API, so every MCP consumer must obtain a valid API key.

View the full MCP tool list, input schemas, and setup snippets in our [MCP Reference](https://mcp.reference.langfuse.com).

## Tools

<table className="[&_code]:rounded-full [&_code]:border [&_code]:border-border [&_code]:bg-muted [&_code]:px-2 [&_code]:py-1 [&_code]:text-muted-foreground">
  <tbody>
    <tr>
      <td className="px-3">
        <strong>Prompts</strong>
        
          <code>getPrompt</code>
          <code>getPromptUnresolved</code>
          <code>listPrompts</code>
          <code>createTextPrompt</code>
          <code>createChatPrompt</code>
          <code>updatePromptLabels</code>
        
      </td>
    </tr>
    <tr>
      <td className="px-3">
        <strong>Observations</strong>
        
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ listObservations</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ getObservation</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ getObservationFieldSchema</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ getObservationFilterSchema</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ getObservationFilterValues</code>
        
      </td>
    </tr>
    <tr>
      <td className="px-3">
        <strong>Metrics</strong>
        
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ getMetricsSchema</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ queryMetrics</code>
        
      </td>
    </tr>
    <tr>
      <td className="px-3">
        <strong>Scores</strong>
        
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ listScores</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ getScore</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ createScore</code>
        
      </td>
    </tr>
    <tr>
      <td className="px-3">
        <strong>Score configs</strong>
        
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ listScoreConfigs</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ getScoreConfig</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ createScoreConfig</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ updateScoreConfig</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ deleteScoreConfig</code>
        
      </td>
    </tr>
    <tr>
      <td className="px-3">
        <strong>Comments</strong>
        
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ listComments</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ getComment</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ createComment</code>
        
      </td>
    </tr>
    <tr>
      <td className="px-3">
        <strong>Datasets</strong>
        
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ listDatasets</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ getDataset</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ upsertDataset</code>
        
      </td>
    </tr>
    <tr>
      <td className="px-3">
        <strong>Dataset items</strong>
        
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ listDatasetItems</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ getDatasetItem</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ upsertDatasetItem</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ deleteDatasetItem</code>
        
      </td>
    </tr>
    <tr>
      <td className="px-3">
        <strong>Dataset runs</strong>
        
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ listDatasetRuns</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ getDatasetRun</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ deleteDatasetRun</code>
        
      </td>
    </tr>
    <tr>
      <td className="px-3">
        <strong>Dataset run items</strong>
        
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ listDatasetRunItems</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ createDatasetRunItem</code>
        
      </td>
    </tr>
    <tr>
      <td className="px-3">
        <strong>Models</strong>
        
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ listModels</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ getModel</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ createModel</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ deleteModel</code>
        
      </td>
    </tr>
    <tr>
      <td className="px-3">
        <strong>Annotation queues</strong>
        
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ listAnnotationQueues</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ getAnnotationQueue</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ createAnnotationQueue</code>
        
      </td>
    </tr>
    <tr>
      <td className="px-3">
        <strong>Annotation queue items</strong>
        
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ listAnnotationQueueItems</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ getAnnotationQueueItem</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ createAnnotationQueueItem</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ updateAnnotationQueueItem</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ deleteAnnotationQueueItem</code>
        
      </td>
    </tr>
    <tr>
      <td className="px-3">
        <strong>Annotation queue assignments</strong>
        
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ createAnnotationQueueAssignment</code>
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ deleteAnnotationQueueAssignment</code>
        
      </td>
    </tr>
    <tr>
      <td className="px-3">
        <strong>Media</strong>
        
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ getMedia</code>
        
      </td>
    </tr>
    <tr>
      <td className="px-3">
        <strong>Health</strong>
        
          <code className="border-green-300! bg-green-100! text-green-900! dark:border-green-900! dark:bg-green-950! dark:text-green-300!">+ getHealth</code>
        
      </td>
    </tr>
  </tbody>
</table>

## Feedback

We'd love to hear about your experience and learn more about how you are using the MCP server. Please share your use cases, feedback, and ideas in our [GitHub Discussion](https://github.com/orgs/langfuse/discussions/10605).

## Get started

- [MCP Server Documentation](/docs/api-and-data-platform/features/mcp-server) - Complete setup guide
- [MCP Reference](https://mcp.reference.langfuse.com) - Current tools, setup snippets, schemas, and generated requests

<!-- agent-instructions -->

---

## Agent Instructions

This page is part of the [Langfuse](https://langfuse.com) documentation, published as plain Markdown for AI agents. Every page is available as Markdown by appending `.md` to its URL, or by sending an `Accept: text/markdown` header. This page: `https://langfuse.com/changelog/2026-05-29-mcp-update.md`.

### Querying these docs

If the answer is not on this page, query the documentation instead of guessing:

- **Semantic search** across all Langfuse docs, returning an answer with the relevant pages and excerpts. Ask a specific, self-contained question:

  ```bash
  curl -sG "https://langfuse.com/api/search-docs" --data-urlencode "query=How do I trace a LangGraph agent?"
  ```

- **Index of every page**: <https://langfuse.com/llms.txt>, with per-section indexes [llms-docs.txt](https://langfuse.com/llms-docs.txt), [llms-integrations.txt](https://langfuse.com/llms-integrations.txt), and [llms-self-hosting.txt](https://langfuse.com/llms-self-hosting.txt).

### Before writing Langfuse code

- **Install the [Langfuse Agent Skill](https://langfuse.com/docs/api-and-data-platform/features/agent-skill).** It encodes Langfuse's own best practices for instrumentation, prompt management, and evaluation, and materially improves results.
- **Read [What does a good trace look like?](https://langfuse.com/docs/observability/best-practices.md)** before instrumenting an application.
- **Verify endpoints, parameters, and response fields** against the [API reference](https://api.reference.langfuse.com) instead of inferring them from code examples.
- **Use the [Langfuse CLI](https://langfuse.com/docs/api-and-data-platform/features/cli)** (`npx langfuse-cli api <resource> <action>`) to read or write traces, prompts, datasets, and scores from the terminal.

Found an error in these docs? Please open an issue at <https://github.com/langfuse/langfuse-docs/issues>.