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Langfuse uses Github Discussions for Support and Feature Requests.
We're hiring. Join us in Product Engineering and Developer Relations.

Langfuse Overview

Develop

• LLM Observability: Instrument your app and start ingesting traces to Langfuse (Quickstart, Integrations Tracing)
• Langfuse UI: Inspect and debug complex logs (Demo, Tracing)
• Prompt Management: Manage, version and deploy prompts from within Langfuse (Prompt Management)
• Prompt Engineering: Test and iterate on your prompts with the LLM Playground

Monitor

• LLM Analytics: Track metrics (cost, latency, quality) and gain insights from dashboards & data exports (Analytics)
• LLM Evaluations: Collect and calculate scores for your LLM completions (Scores & Evaluations)
  • Run (Model-based evaluations) and LLM-as-a-Judge within Langfuse
  • Collect user feedback (User Feedback)
  • Manually score LLM outputs in Langfuse (Manual Scores)

Test

• Experiments: Track and test app behaviour before deploying a new version
  • Datasets let you test expected in and output pairs and benchmark performance before deploying (Datasets)
  • Track versions and releases in your application (Experimentation, Prompt Management)

Get started

Langfuse Cloud

Managed deployment by the Langfuse team, generous free-tier (hobby plan), no credit card required.

» Langfuse Cloud

Self-Hosting Open Source LLM Observability with Langfuse

Localhost (docker)

# Clone repository
git clone https://github.com/langfuse/langfuse.git
cd langfuse

# Run server and database
docker compose up -d

→ Learn more about deploying locally

Self-host (docker)

Langfuse is simple to self-host and keep updated. It currently requires only a single docker container and a postgres database. → Self Hosting Instructions

Templated deployments: Railway, GCP, AWS, Azure, Kubernetes and others

Get Started

API Keys

You need a Langfuse public and secret key to get started. Sign up here and find them in your project settings.

Ingesting Data · Instrumenting Your Application · LLM Observability with Langfuse

Note: We recommend using our fully async, typed SDKs that allow you to instrument any LLM application with any underlying model. They are available in Python (Decorators) & JS/TS. The SDKs will always be the most fully featured and stable way to ingest data into Langfuse.

See the → Quickstart to integrate Langfuse.

LLM Observability Integrations

Packages integrated with Langfuse:

Questions and feedback

Ideas and roadmap

• Roadmap
• GitHub Discussions
• Feature Requests

Support and feedback

In order of preference the best way to communicate with us:

• GitHub Discussions (preferred): Contribute ideas, support requests and report bugs
• Discord: community support
• Privately: contact at langfuse dot com

Contributing to Langfuse

• Vote on Ideas
• Raise and comment on Issues
• Open a PR - see CONTRIBUTING.md for details on how to setup a development environment.

License

This repository is MIT licensed, except for the ee folders. See LICENSE and docs for more details.

Misc

GET API to export your data

GET routes to use data in downstream applications (e.g. embedded analytics). You can also access them conveniently via the SDKs (docs).

Security & Privacy

We take data security and privacy seriously. Please refer to our Security and Privacy page for more information.

Telemetry

By default, Langfuse automatically reports basic usage statistics of self-hosted instances to a centralized server (PostHog).

This helps us to:

1. Understand how Langfuse is used and improve the most relevant features.
2. Track overall usage for internal and external (e.g. fundraising) reporting.

None of the data is shared with third parties and does not include any sensitive information. We want to be super transparent about this and you can find the exact data we collect here.

You can opt-out by setting TELEMETRY_ENABLED=false.

Star History

Open Source Projects Using Langfuse

Top open-source Python projects that use Langfuse, ranked by stars (Source):

Repository	Stars
langgenius / dify	54865
open-webui / open-webui	51531
lobehub / lobe-chat	49003
langflow-ai / langflow	39093
run-llama / llama_index	37368
chatchat-space / Langchain-Chatchat	32486
FlowiseAI / Flowise	32448
mindsdb / mindsdb	26931
twentyhq / twenty	24195
PostHog / posthog	22618
BerriAI / litellm	15151
mediar-ai / screenpipe	11037
formbricks / formbricks	9386
anthropics / courses	8385
GreyDGL / PentestGPT	7374
superagent-ai / superagent	5391
promptfoo / promptfoo	4976
onlook-dev / onlook	4141
Canner / WrenAI	2526
pingcap / autoflow	2061
MLSysOps / MLE-agent	1161
open-webui / pipelines	1100
alishobeiri / thread	1074
topoteretes / cognee	971
bRAGAI / bRAG-langchain	823
opslane / opslane	677
dynamiq-ai / dynamiq	639
theopenconversationkit / tock	514
andysingal / llm-course	394
phospho-app / phospho	384
sentient-engineering / agent-q	370
sql-agi / DB-GPT	324
PostHog / posthog-foss	305
vespperhq / vespper	304
block / goose	295
aorwall / moatless-tools	291
dmayboroda / minima	221
RobotecAI / rai	172
i-am-alice / 3rd-devs	148
8090-inc / xrx-sample-apps	138
babelcloud / LLM-RGB	135
souzatharsis / tamingLLMs	129
LibreChat-AI / librechat.ai	128
deepset-ai / haystack-core-integrations	126