# Langfuse — Open Source LLM Observability

> Langfuse is an open-source LLM engineering platform for tracing, prompt management, evaluation, and debugging AI apps. 24.1K+ GitHub stars. Self-hosted or cloud. MIT.

## Install

Save in your project root:

## Quick Use

```bash
# Install
pip install langfuse openai

# Add tracing to your LLM calls
python -c "
from langfuse.openai import openai
# Automatic tracing — just swap the import
client = openai.OpenAI()
response = client.chat.completions.create(
    model='gpt-4o-mini',
    messages=[{'role': 'user', 'content': 'Hello!'}]
)
print(response.choices[0].message.content)
# Traces visible at http://localhost:3000
"

# Self-host with Docker
docker compose up -d  # from langfuse repo
```

---

## Intro

Langfuse is an open-source LLM engineering platform that helps teams collaboratively develop, monitor, evaluate, and debug AI applications. With 24,100+ GitHub stars and MIT license, Langfuse provides LLM observability with detailed tracing of calls, retrieval, embeddings, and agent actions. It includes centralized prompt management with version control, evaluation pipelines (LLM-as-judge, user feedback, manual labeling), dataset testing, an interactive playground, and SDKs for Python and JavaScript. Self-host in minutes with Docker, Kubernetes, or deploy on AWS/Azure/GCP.

**Best for**: Teams building production AI apps who need observability, prompt management, and evaluation
**Works with**: Claude Code, OpenAI Codex, Cursor, Gemini CLI, Windsurf
**Integrations**: OpenAI, LangChain, LlamaIndex, Haystack, Vercel AI SDK

---

## Key Features

- **LLM tracing**: Track every call, retrieval, embedding, and agent action
- **Prompt management**: Version control, collaboration, server/client caching
- **Evaluations**: LLM-as-judge, user feedback, manual labeling, custom pipelines
- **Datasets**: Benchmark testing for continuous improvement
- **Playground**: Interactive prompt testing and iteration
- **Self-hosted**: Docker, Kubernetes, Terraform (AWS/Azure/GCP)

---

### FAQ

**Q: What is Langfuse?**
A: Langfuse is an LLM observability platform with 24.1K+ stars for tracing, prompt management, and evaluation. Self-host with Docker or use cloud. MIT licensed.

**Q: How do I install Langfuse?**
A: `pip install langfuse openai`. Swap `from openai import OpenAI` to `from langfuse.openai import openai` for automatic tracing.

---

## Source & Thanks

> Created by [Langfuse](https://github.com/langfuse). Licensed under MIT.
> [langfuse/langfuse](https://github.com/langfuse/langfuse) — 24,100+ GitHub stars

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Source: https://tokrepo.com/en/workflows/49a8eb0b-b44b-46c2-b3c8-b54e55fb224f
Author: AI Open Source