langfuse

Query Langfuse REST API traces, observations, scores, and datasets.

Updated Mar 31, 2026
One-click install
npx skills add https://github.com/efoo-team/skills --skill langfuse-efoo-team
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: langfuse
Source: https://github.com/efoo-team/skills/tree/main/skills/langfuse
Command: npx skills add https://github.com/efoo-team/skills --skill langfuse-efoo-team

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

This Skill enables users to query, analyze, and debug large language model (LLM) observability data from Langfuse, supporting troubleshooting agent performance and managing costs.

Core Features & Use Cases

  • Query Trace and Observation Data: Retrieve detailed information on agent runs, input/output, latency, and costs.
  • Debug Agent Failures: Inspect errors and warnings within trace data to identify issues.
  • Analyze Costs and Latency: Summarize and break down resource usage metrics for performance optimization.
  • Review Prompt and Dataset Versions: Audit different prompt iterations and dataset states to ensure consistency.

Quick Start

Query the Langfuse REST API to list recent traces and inspect detailed logs for debugging.

Frequently Asked Questions about langfuse

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I debug LLM agent failures using observability data?

Debug LLM agent failures by querying trace and observation data to inspect errors, warnings, and detailed logs. Investigate specific agent runs to identify the root cause of performance issues and unexpected behaviors within your application.

What is the best way to analyze LLM API costs and latency?

Analyze LLM API costs and latency by summarizing resource usage metrics from observation data. Break down token counts and execution times across different traces to optimize overall performance and manage operational expenses effectively.

Do I need an API key to query LLM traces and datasets?

Yes, you need an API key to query LLM traces and datasets. Accessing detailed prompt histories, observation scores, and agent run metrics requires authenticating REST API requests with valid credentials to retrieve the observability data securely.

Can I audit prompt histories and dataset versions for consistency?

Yes, you can audit prompt histories and dataset versions for consistency. Query the REST API to review different prompt iterations and dataset states, ensuring that changes to your LLM workflows maintain expected behavior over time.

Why does my LLM observability query return limited trace data?

LLM observability queries may return limited trace data due to restricted API key permissions or filtering parameters. Ensure your credentials have sufficient access rights and adjust your REST API request parameters to broaden the scope of retrieved logs.