BenchLLM

BenchLLM is an open-source Python library from V7 Labs for testing and evaluating large language model applications. It lets developers build test suites for models, chains, and agents, defining test cases in JSON or YAML, and then run them through a command-line interface to check whether outputs still meet expectations after a code or prompt change. Evaluation can run automatically, interactively with a human reviewing each output, or through custom evaluation strategies that developers define themselves. The tool is built for continuous integration: it's designed to catch regressions in LLM-powered applications, such as chains built with Langchain or agents like AutoGPT, before they reach production, and it works out of the box with OpenAI's API alongside other LLM providers. Test suites can be organized and versioned, and BenchLLM generates reports summarizing accuracy so teams can compare runs over time and spot hallucinations or inconsistent responses. BenchLLM targets AI engineers and developers building applications on top of LLMs who need a repeatable way to test non-deterministic outputs, something traditional unit testing doesn't handle well. The project is open source under the MIT license and available on GitHub, with function mocking added in more recent releases. V7 Labs describes it as being in an early stage of development, so its interfaces and features may still change quickly.