TL;DR: OpenAI’s GPT-5.5, GPT-5.4, and Codex went GA on Amazon Bedrock on June 1, 2026. To get a feel for it, I wired up two Strands agents — Claude Opus 4.8 and GPT-5.5 — and let them chat, with Opus playing the older sibling welcoming the newcomer. It took about 50 lines. The charming part was the banter. The instructive part was that the two agents needed two different APIs to talk, which is a nuance in the “one API for every model” story worth understanding before you build.