It is available in open source with Apache 2.0 licence. Its free-tier allows 1K daily events only.
Things To Consider
Early with regards to Open source adoption of the tool.
Benefits
Its a tracing tool that works with Langchain & OpenAI agents. It is completely model agnostic.
Its cloud offering gives option to benchmarks models and prompts against your ideal responses.
It also has a feature called Radar which helps in helps categorise LLM responses based on pre-defined criteria so that you can visit them later for analysis.