OpenAI GPT-5.4 and GPT-5.5 now available in US East on Amazon Bedrock

The regional expansion brings OpenAI's frontier models to US East (N. Virginia), Bedrock's largest region, after an initial availability that began earlier in June. GPT-5.5 is marketed as OpenAI's most capable model for advanced coding, reasoning, computer use, document workflows, and long-running agentic tasks — a direct competitive pairing against Claude Fable 5, which went GA on the same platform days earlier.

The move is strategically striking: AWS, long the cloud home of Anthropic, now hosts OpenAI's flagship models too, turning Bedrock into a neutral multi-frontier marketplace. For enterprises, the appeal is choosing GPT-5.5 or Fable 5 within the same security, identity, and data controls, with no separate vendor contract.

The timing matters competitively — placing GPT-5.5 next to Fable 5 on Bedrock the same week sets up direct head-to-head evaluation, and an r/OpenAI thread (218 upvotes) already debated how GPT-5.5 stacks up against Fable in real-world coding. The expansion also hedges AWS against any single model vendor as DeepSeek's pricing and Anthropic's data-sharing terms unsettle customers.