Opik provides full-stack LLM observability through trace capture, structured evaluation pipelines, and production monitoring. It supports 30+ LLM-as-a-Judge metrics covering answer relevance, hallucination, context precision, and more, alongside a plain-text assertion system for defining unit tests without writing individual eval metrics. The platform includes Ollie, an AI coding assistant that reads traces, suggests fixes, and writes them directly to the development codebase with built-in version control and regression testing. Opik is fully open-source (hosted on GitHub under the comet-ml org) and can be self-hosted or used via the managed Comet cloud.