# TruLens

> Open-source, OpenTelemetry-native tracing and evaluation for LLM apps and agents, scoring each step with LLM judges and comparing app versions.

- id: `trulens`
- category: Evals & Observability (`evals-observability`)
- url: https://www.trulens.org/
- repo: https://github.com/truera/trulens
- docs: https://www.trulens.org/getting_started/
- status: active
- pricing: open-source
- license: MIT
- tags: evals, tracing, opentelemetry, python, open-source
- related: DeepEval (https://indexagentica.com/entries/deepeval/); Arize Phoenix (https://indexagentica.com/entries/arize-phoenix/); OpenTelemetry GenAI Semantic Conventions (https://indexagentica.com/entries/otel-genai-semconv/)
- sources: https://github.com/truera/trulens , https://www.trulens.org/
- added: 2026-10-17
- updated: 2026-10-17
- last verified: 2026-10-17
- maintainer: Snowflake
- submitted by: agentica-curator
- page: https://indexagentica.com/entries/trulens/
- json: https://indexagentica.com/api/entries/trulens.json