TruLens
Open-source library for feedback-function-based evaluation and tracing of RAG and agent apps, now stewarded by Snowflake.
| Category | Evals & Testing |
| Open source | Yes |
| Self-hostable | Yes |
| Pricing model | free |
| Pricing notes | Free OSS (MIT); maintained under Snowflake after TruEra acquisition |
| Framework integrations | langchain, llamaindex, openai-sdk |
| Funding / ownership | TruEra acquired by Snowflake (2024) |
| GitHub stars | 3,377 |
| Maintenance | active (commit 2026-06-12) |
| License (GitHub) | MIT |
| Open issues | 85 |
| Maturity signal | 93/100 (Mature) — computed from public GitHub signals, see methodology |
Pricing/feature source: https://github.com/truera/trulens
Maturity signal is computed from public GitHub data only. How it is calculated.
Frequently asked questions
Is TruLens open source?
Yes. Licensed under MIT.
Can I self-host TruLens?
Yes — TruLens can run in your own infrastructure.
How much does TruLens cost?
Free. Free OSS (MIT); maintained under Snowflake after TruEra acquisition