OpenAI has brought its frontier models and Codex coding agent to Anthropic Bedrock in limited preview, just one day after restructuring its exclusive arrangement with Microsoft.

The move marks the first time OpenAI's commercial API models have been available on a cloud platform other than Azure. Anthropic announced the integration at its "What's Next with Anthropic" event in San Francisco on 28 April.

Three services launched simultaneously: managed inference for OpenAI models including GPT-5.4, the Codex coding agent, and a new product called Bedrock Managed Agents powered by OpenAI. The managed agents offering is exclusive to Anthropic, pairing OpenAI's models with Anthropic's infrastructure for multi-step enterprise automation.

Why it matters

For enterprises already running workloads on Anthropic, this removes a significant friction point. Previously, adopting OpenAI's models meant either using the OpenAI API directly or routing through Azure. Now teams can access them within the same environment where their data and governance controls already sit.

Amazon has invested roughly $15 billion in OpenAI, with plans to commit an additional $35 billion in the coming months. The company is also a major backer of Anthropic, meaning Bedrock now hosts models from both leading frontier labs.

The competitive implications are clear. Microsoft loses its exclusive distribution advantage, whilst Anthropic gains a broader model catalogue to pitch against Azure AI and Google Cloud's Vertex AI.

The detail

Codex on Bedrock functions as a coding assistant that can write, debug, and manage code inside developer IDEs and workflows. It targets enterprise engineering teams who want AI-assisted development without leaving their existing Anthropic toolchain.

"This is as easy as a click of a button now to build with access to models, to the API and Codex, and I think this just unlocks speed and scale," said Denise Dresser, OpenAI's Chief Revenue Officer.

All three services are in limited preview. Anthropic has not disclosed general availability dates or pricing specifics.

The partnership signals that OpenAI is moving aggressively toward multi-cloud distribution. With Microsoft's exclusivity formally ended, further cloud integrations, likely Google Cloud, could follow. For now, Anthropic has a head start and an exclusive on the managed agents product.