ModelRefs / TruLens — AI Glossary

TruLens — AI Glossary

An open-source evaluation and observability framework for LLM applications, supporting RAG triads and custom feedback functions.

Overview

TruLens (TruEra) records LLM app inputs, outputs, and intermediate steps; evaluates them using 'feedback functions' (LLM-based or heuristic). Supports the RAG triad (groundedness, answer relevance, context relevance). Integrates with LlamaIndex, LangChain, and custom apps. Dashboard for tracking quality across app versions.

Reference details

Topicevaluation
Last reviewed2026-06-24

Commonly confused with

An evaluation framework rather than a hosted platform, which is the distinction that matters against Langfuse, Braintrust or Phoenix: it gives you feedback functions to score RAG behaviour in code, not a service to send traces to. Its RAG triad — context relevance, groundedness, answer relevance — is the same decomposition RAGAS uses under different names.

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Frequently asked questions

What is TruLens?

An open-source evaluation and observability framework for LLM applications, supporting RAG triads and custom feedback functions.

What concepts are related to TruLens?

Closely related concepts include ragas, langsmith, langfuse.