GPT-5.6 enters AWS Kiro with a lower-cost coding test

OpenAI says the GPT-5.6 model family is now available in Kiro, AWS's software development agent. The models are intended for long-running work such as planning, coding, review, and testing. 1

OpenAI and AWS say their testing found that GPT-5.6 Terra completed successful Terminal-Bench 2.1 tasks in Kiro at roughly 82% lower cost. The practical question for teams is whether that lower cost also means fewer retries in real codebases. 1