langfuse-observability

Trace LLM calls, spans, and costs in Python applications with Langfuse.

1|Updated Mar 10, 2026
One-click install
npx skills add https://github.com/aleonsa/claude-config --skill langfuse-observability-aleonsa
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: langfuse-observability
Source: https://github.com/aleonsa/claude-config/tree/main/claude/skills/langfuse-observability
Command: npx skills add https://github.com/aleonsa/claude-config --skill langfuse-observability-aleonsa

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

This Skill addresses the challenge of understanding and debugging complex LLM applications by providing robust observability, tracing, and evaluation capabilities.

Core Features & Use Cases

  • End-to-end Tracing: Track LLM calls, agentic workflows, and spans across your application.
  • Prompt Management: Version, manage, and retrieve prompts directly from Langfuse.
  • Cost & Latency Monitoring: Monitor token usage, costs, and latency per user or tenant.
  • Evaluation: Build and run evaluation datasets to score LLM performance.
  • Use Case: Integrate Langfuse into your FastAPI application to automatically trace all LLM interactions, tag them with user and tenant IDs, and visualize performance metrics in the Langfuse UI.

Quick Start

Integrate Langfuse into your Python application by following the setup instructions in the documentation.

Frequently Asked Questions about langfuse-observability

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

FAQPage Schema
How do I trace LLM calls and agentic workflows in Python?

Trace LLM calls by integrating the Langfuse SDK into your Python application to capture spans, agentic workflows, and interactions automatically. This provides end-to-end observability for debugging complex LLM application behavior.

What is the best way to monitor LLM cost and latency per user?

Monitor LLM cost and latency per user by tagging traced LLM interactions with user and tenant IDs. This allows you to visualize token usage, cost tracking, and latency metrics for specific users within the Langfuse UI.

Does Langfuse observability work with FastAPI applications?

Yes, Langfuse observability integrates with FastAPI applications to automatically trace LLM interactions. You can tag these interactions with user and tenant IDs to support multi-tenant isolation and visualize performance metrics in the UI.

Can I manage and version prompts directly within my LLM application?

Yes, you can manage and version prompts directly from Langfuse within your LLM application. This allows you to retrieve specific prompt versions programmatically during runtime to maintain consistency across deployments.

How do I build and run evaluation datasets to score LLM performance?

You can build and run evaluation datasets to score LLM performance using Langfuse's evaluation capabilities. This allows you to systematically assess and quantify your LLM application outputs directly within your observability workflow.

Do I need API keys to set up LLM observability?

Yes, you need Langfuse SDK and API keys to set up and operate LLM observability. These credentials are required to authenticate your Python application and transmit trace data to the Langfuse platform.