Confident AI is a creator of the DeepEval. DeepEval is a package for unit testing LLMs. Using DeepEval, everyone can build robust language models through faster iterations using both unit testing and integration testing. `DeepEval provides support for each step in the iteration from synthetic data creation to testing.

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Installation and Setup

You need to get the DeepEval API credentials. You need to install the DeepEval Python package: 
pip install deepeval

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Callbacks

See an example. 
from langchain.callbacks.confident_callback import DeepEvalCallbackHandler