Prometheus-Eval is an open-source framework designed to evaluate the outputs of large language models using specialized evaluator models known as Prometheus. The project provides tools, datasets, and scripts that allow developers and researchers to measure the quality of LLM responses through automated scoring rather than relying solely on human evaluators. It implements an “LLM-as-a-judge” approach in which a dedicated language model analyzes instruction–response pairs and assigns scores or rankings based on predefined evaluation criteria. The repository includes a Python package that provides a straightforward interface for running evaluations and integrating them into model development pipelines. It also provides training data and utilities for fine-tuning evaluator models so they can assess outputs according to custom scoring rubrics such as helpfulness, accuracy, or style.
Features
- Python package for evaluating instruction-response pairs produced by large language models
- Support for fine-grained scoring using customizable evaluation rubrics
- Open-source evaluator models designed to approximate human judgment
- Tools and datasets for training and fine-tuning evaluation models
- Support for both absolute grading and pairwise ranking evaluation methods
- Integration into automated benchmarking pipelines for LLM testing and comparison