Library / SDK
Observability & Evaluation
Opik
1Open-source 2LLM 3evaluation 4and 5observability 6platform
the six Ws · specification
W1
Who
Maintained by Comet ML, an ML monitoring vendor.
W2
What
A platform for tracing, evaluating, and monitoring LLM apps with datasets, experiments, and prompt management.
W3
Where
A self-hostable open-source server plus SDKs, or Comet's managed cloud.
W4
When
Reach for it when you want a self-hostable stack for LLM tracing and evaluation.
W5
Why
Combines observability and evaluation in one Apache-licensed tool without lock-in.
W6
With
Integrates with OpenAI, LangChain, LlamaIndex, LiteLLM, and OpenTelemetry.
W7
Watch
Maintained by Comet ML; open-source (Apache-2.0) and fully self-hostable, with an optional paid cloud (open-core). Self-hosted keeps data local.