[How to use prebuilt evaluators | 🦜️🛠️ LangSmith](https://docs.smith.langchain.com/evaluation/how_to_guides/prebuilt_evaluators): LLM should read this page when needing to use prebuilt evaluators in LangSmith, implementing LLM-as-a-judge for evaluation, or integrating evaluation into testing frameworks. This page explains how to use the openevals package for ready-made LangSmith evaluators, covering setup requirements, implementation with Python and TypeScript, and integration with pytest/Vitest for running evaluations that automatically log results as feedback.

