Software Development & Delivery · Preview

langfuse

🪢 Open source LLM engineering platform: LLM Observability, metrics, evals, prompt management, playground, datasets. Integrates with OpenTelemetry, Langchain, OpenAI SDK, LiteLLM, and more. 🍊YC W23

Best fitUsers who want source-backed project understanding before installing it.

Check whether this project matches your task before installing it.

What it can doprompt, recipe, host_instruction, eval, preflight

Review the portable capability path.

Before continuingVerify in a sandbox

Do not treat a preview pack as a proven local install.

GitHub snapshot27k stars

2.8k forks · 156 contributors

Official first step Read manual preview Source repository

Preview status · 2026-05-16

What is langfuse?

Langfuse serves as a centralized platform for capturing and analyzing interactions between AI models and end users. The project is MIT licensed and supports both cloud-hosted and self-host...
Best fit: Users who want source-backed project understanding before installing it.
Capability added to an AI workflow: prompt, recipe, host_instruction, eval, preflight
Evidence base: https://github.com/langfuse/langfuse, https://github.com/langfuse/langfuse, https://github.com/langfuse/langfuse#readme
Preview pages are noindex until English quality, canonical, and citation gates pass.
langfuse still needs sandbox verification before production use.

Quick decision

Use this section to decide whether the project is worth a deeper read.

Best forUsers who want source-backed project understanding before installing it.

Match the project to your task before installing it.

Capabilityprompt, recipe, host_instruction, eval, preflight

Repositorylangfuse/langfuse

27k stars · 2.8k forks

What it can do

Translate the upstream project into concrete capabilities the user can judge before installing.

Project Introduction

Project Structure

Related topics: Monorepo Configuration, System Architecture

Sources: [pnpm-workspace.yaml](https://github.com/langfuse/langfuse/blob/main/pnpm-workspace.yaml)

Quickstart Guide

System Architecture

Related topics: Project Structure, Database Schema (Prisma), Queue System (Redis/BullMQ)

Sources: [packages/shared/src/db.ts:1-50]()

Monorepo Configuration

Related topics: Project Structure, System Architecture

Sources: [packages/config-eslint/index.js]()

Sources: https://github.com/langfuse/langfuse, Human Manual, Project Pack evidence, and downstream validation signals.

Community Discussion Evidence

Project-level external discussion stays visible on the detail page, not only inside the manual.

Stars27k stars

Forks2.8k forks

Contributors156 contributors

Licenseunknown

Community Discussion Evidence

12 source-linked items

Review these external discussions before using langfuse with real data or production workflows. They are review inputs, not standalone proof that the project is production-ready.

01
bug: unnamed trace name in Langfuse UI
github / github_issue
02
bug: Socket timeout. Expecting data, but didn't receive any in 30000ms o
github / github_issue
03
bug: Using client with context manager breaks the scoring
github / github_issue
04
bug: Worker shutdown takes ~1 hour in self hosted kubernetes
github / github_issue
05
bug: AsyncStream' object has no attribute 'usage' when integrated with S
github / github_issue
06
v3.174.0
github / github_release
07
v3.173.0
github / github_release
08
v3.172.1
github / github_release
09
v3.172.0
github / github_release
10
v3.171.0
github / github_release
11
v3.170.0
github / github_release
12
v3.169.0
github / github_release

How to start

Only source-backed commands are shown here. Verify them in an isolated environment first.

Try the prompt first

Test the workflow without installing the upstream project.

preview

Read the Human Manual

Understand inputs, outputs, limits, and failure modes.

manual

Take context to your AI host

Use the compiled assets in your preferred AI environment.

context

Run sandbox verification

Confirm install commands and rollback before using a primary environment.

verify

pip install langfuse

Official start command · https://github.com/langfuse/langfuse#readme · verified: yes

Human Manual

The English page must expose the real manual, not a short placeholder.

8+ sections · Human Manual

langfuse Manual

Langfuse serves as a centralized platform for capturing and analyzing interactions between AI models and end users. The project is MIT licensed and supports both cloud-hosted and self-host...

Open the full manual

langfuse Human Manual
Table of Contents
Project Introduction
Related Pages
Overview
Core Purpose
High-Level Architecture
Technology Stack

Project Introduction

Project Structure

Related topics: Monorepo Configuration, System Architecture

Sources: [pnpm-workspace.yaml](https://github.com/langfuse/langfuse/blob/main/pnpm-workspace.yaml)

Quickstart Guide

System Architecture

Related topics: Project Structure, Database Schema (Prisma), Queue System (Redis/BullMQ)

Sources: [packages/shared/src/db.ts:1-50]()

Monorepo Configuration

Related topics: Project Structure, System Architecture

Sources: [packages/config-eslint/index.js]()

AI Context Pack and portable assets

After deciding to continue, take the project context into your own AI host.

Complete pack plus user-owned assets

These files are planning and verification assets for Claude Code, Codex, Gemini, Cursor, ChatGPT, and other AI hosts.

Download complete pack Read Human Manual

BundleComplete Project Pack AssetAI Context Pack AssetBoundary & Risk Card AssetHuman Manual AssetPitfall Log AssetPrompt Preview AssetQuick Start ManifestPROJECT_PACK.json

Preflight checks

Treat this preview as a planning asset, not proof that your local environment is ready.

The manual is generated from source-linked project files and Doramagic validation signals.
Community evidence warnings stay visible instead of being converted into marketing claims.
The preview remains noindex until English quality and reciprocal indexing gates are explicitly opened.
Use the upstream repository as the final authority for installation commands, license, and version-specific behavior.