Technical report
Codex: Evaluating LLMs Trained on Code (HumanEval)
The model is a GPT language model further trained on a large corpus of GitHub code so it can turn a function signature and docstring into a working implementation. Rather than scoring generated code by similarity to a reference, HumanEval defines 164 hand-written problems with unit tests and reports pass@k, the chance that at least one of k sampled solutions passes all tests. This functional metric, plus the finding that sampling many candidates raises success rates, shaped how code-generation models are evaluated and underpinned tools like GitHub Copilot.