Open source llm-observability projects

Every project in the registry tagged llm-observability, ranked by real GitHub adoption.

projects 12 combined stars ★ 98K refresh nightly
01 Langfuse ★ 35K

Open source LLM engineering platform for AI-powered applications

last push3 hours ago languageTypeScript license
02 opik ★ 22K

Debug, evaluate, and monitor your LLM applications, RAG systems, and agentic workflows with comprehensive tracing, automated evaluations, and production-ready d

last push4 hours ago languagePython licenseApache-2.0
03 voltagent ★ 11K

AI Agent Engineering Platform built on an Open Source TypeScript AI Agent Framework

last push21 days ago languageTypeScript licenseMIT
04 Bifrost ★ 8.1K

Ultra-fast AI gateway with enterprise-grade reliability

last push3 hours ago languageGo licenseApache-2.0
05 Helicone ★ 6.2K

Build reliable AI apps with comprehensive observability

last push28 hours ago languageTypeScript licenseApache-2.0
06 Latitude ★ 4.7K

Full observability for AI agents in production

last push3 hours ago languageTypeScript licenseMIT
07 Logfire ★ 4.5K

Powerful observability made simple for developers

last push5 hours ago languagePython licenseMIT
08 Laminar ★ 3.3K

AI-powered platform for engineering LLM products

last push5 hours ago languageTypeScript licenseApache-2.0
09 future-agi ★ 2.0K

Open-source, end-to-end platform for evaluating, observing, and improving LLM and AI agent applications. Tracing · Evals · Simulations · Datasets · Gateway · Gu

last push9 hours ago languagePython licenseApache-2.0
10 Tracely-ai ★ 1.4K

Trace-native CI/CD for AI agents — production failures become regression tests that block the PR. Auto-detect, cluster, freeze into hermetic cases, replay in CI

last push34 hours ago languagePython licenseMIT
11 Spanlens ★ 13

LLM observability: cost, latency, and traces in one place

last push4 days ago languageTypeScript licenseMIT
12 Grepture ★ 8

Trace, evaluate, and protect every LLM call in one SDK

last push23 days ago languageTypeScript licenseAGPL-3.0

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Frequently asked questions

How many open source llm-observability projects are there?

This registry tracks 12 projects tagged llm-observability, with 97,617 GitHub stars between them. The most-adopted is Langfuse at 34,729 stars.

Are these llm-observability projects free to use?

Yes — 11 of the 12 carry an explicit open-source licence across 3 distinct licences, so there is no licence fee. Where a project also sells a hosted or enterprise version, the self-hosted path remains free.

Which llm-observability project should I choose?

The list above is ranked by GitHub stars, but stars measure attention rather than fit. Check three things on each card: the licence (permissive versus copyleft), the language it is written in, and the last-push date — a high-star project that has not been pushed in a year is a liability.

Are these llm-observability projects still maintained?

12 of the 12 were pushed in the last 90 days, and every card shows its exact last-push date so you can see the rest. Sort your shortlist by that date before committing to a migration.