Open Source LLM Observability & Evaluation using CSS
A curated collection of the best open source tracing, monitoring, and evaluation platforms for LLM and AI-agent applications. using CSS.
Open source LLM engineering platform for AI-powered applications
Stars
Stars growing over the last 30 days36,064Last commit
6 hours agoLicense
MIT
Langfuse provides tracing, evaluations, prompt management, and analytics to debug and improve LLM applications.
Open Source Alternative to:
Open-source LLM tracing & evaluation for AI optimization
Stars
Stars growing over the last 30 days11,913Last commit
11 hours agoLicense
Elastic-2.0
Open-source platform for LLM tracing, evaluation, and optimization. Features automatic instrumentation, prompt playground, and real-time AI application monitoring.
Open Source Alternative to:
Build reliable AI apps with comprehensive observability
Stars
6,227Last commit
8 hours agoLicense
Apache-2.0
Open-source platform for logging, monitoring, and debugging LLM applications. Route, debug, and analyze AI apps with comprehensive observability tools.
Open Source Alternative to:
Build, automate, and improve AI agents with your team
Stars
4,846Last commit
7 hours agoLicense
MIT
Open-source workspace for building and running AI agents: chat-driven development, scheduling, human-in-the-loop approvals, versioning, and tracing. Self-host or use the cloud.
Open Source Alternative to:
Full observability for AI agents in production
Stars
4,728Last commit
20 hours agoLicense
MIT
Open-source platform for monitoring AI agents: captures traces, surfaces failure patterns, alerts on issues, and helps you verify fixes with automated evals.
Open Source Alternative to:
Simulation-based testing and evaluation for AI agents
Stars
4,983Last commit
6 hours agoLicense
Apache-2.0
Tests AI agents through multi-turn simulations, LLM-based scoring, and production tracing so teams can ship reliable agents with confidence.
Open Source Alternative to:
AI-powered platform for engineering LLM products
Stars
Stars growing over the last 30 days3,418Last commit
15 hours agoLicense
Apache-2.0
Laminar is an open-source platform that helps collect, understand, and utilize data for building high-quality LLM applications.
Open Source Alternative to:
Monitor, debug, and scale LLM applications with ease
Stars
Stars growing over the last 30 days2,863Last commit
7 hours agoLicense
Apache-2.0
Open-source observability platform for GenAI and LLM applications. Real-time monitoring, distributed tracing, prompt management, and AI model evaluation built on OpenTelemetry.
Open Source Alternative to:
Experiment tracking platform for ML teams
Stars
393Last commit
8 months agoLicense
Apache-2.0
Open source ML experiment tracking platform with parameter and gradient logging, media tracking, real-time alerts, and full Weights & Biases API compatibility.
Open Source Alternative to:
LLM observability: cost, latency, and traces in one place
Stars
13Last commit
1 day agoLicense
MIT
Drop-in observability platform for OpenAI, Anthropic, and Gemini that logs every request, tracks costs, traces agent workflows, and flags anomalies and PII.
Open Source Alternative to:
c15t – Open-source cookie banner, built for control and lightening fast modern web apps.
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