GPT-5.6 Terra and Luna enter GovCloud

AWS made OpenAI’s GPT-5.6 Terra and Luna generally available in its US-West and US-East GovCloud regions, with 1 million-token context windows and a 90% discount on repeated context through prompt caching, according to AWS’s availability announcement. The release puts OpenAI’s balanced and fast tiers behind Bedrock’s government-region controls, but not its flagship Sol model. Teams serving long-lived code, research, or case histories in regulated environments can now test a single-context workflow without sending prompts to a commercial region; the archive’s analysis of GPT-5.6 Sol’s latency tier is the useful comparison for deciding whether the missing top tier matters.