OpenAI introduces public beta for agents API, streamlining codex harness access

OpenAI has launched the Agents API in public beta, offering developers access to the same infrastructure that powers Codex. The service is live for all developers, with data restricted to U.S. servers and no zero data retention support. The API is built on the open-source Codex harness, which OpenAI claims was refined through scaling efforts for ChatGPT for Work. The platform allows agents to run in OpenAI-managed sandboxes, developers' own infrastructure, or partner sandboxes. OpenAI maintains the harness alongside its models, with versioned access at each model launch. The API supports three sandbox options and can operate without one. Customer-reported performance metrics were also shared, though they are vendor-supplied and not independently verified. The service is organized around four key concepts, including session management through four steps, and includes a quickstart guide for API key permissions and SDK setup.