TruLens

TruLens instruments LLM apps and agents with a decorator, records latency, inputs, outputs, tokens and cost per step, and scores each step with LLM judges that explain their ratings. Tracing is OpenTelemetry-native, so traces are portable to any OTLP backend, and evaluations run either as traces arrive or over a dataset afterwards. It includes the RAG Triad metrics and an Agent GPA judge, and supports comparing app versions on quality, latency and cost. The README lists adopters including Walmart Global Tech, Cisco and J.P. Morgan Chase.