OpenAI opens its Codex harness through Agents API

OpenAI opened its Agents API to all developers in public beta with a $0 platform fee; users still pay for model tokens and tools. In the developer announcement, OpenAI says it handles orchestration, long-running sessions, and context management while builders choose self-hosted, OpenAI-hosted, or partner sandboxes, with nine listed integrations. That makes Codex-style agent harnesses easier to trial, but “free” covers the control plane—not execution, isolation, or usage.