The OpenAI Model Spec

• Annotated with a version history of all eight versions, 2024 to 2026 The Model Spec is OpenAI's public document setting out how it intends its models to behave. In OpenAI's words: "By publishing the Model Spec, we aim to increase transparency around how we shape model behavior and invite public discussion on ways to improve it." This edition prints the version of 29 October 2026 in full, word f...