OpenAI opens Agents API public beta with managed Codex harness
OpenAI
OpenAI released the Agents API in public beta on September 10, exposing the Codex harness as a managed service: OpenAI handles session orchestration, context compaction and recovery while apps supply tools and pick an execution environment (OpenAI-hosted sandbox or self-hosted). Durable sessions support streaming, webhooks, mid-turn steering, MCP servers and up to 4 concurrent subagents; billing is at standard API rates, US-only data residency.
Why it matters
Turns Codex from a CLI/IDE product into an embeddable platform primitive, competing directly with Anthropic's Agent SDK for building production agents on a managed harness.
Importance: 3/5
Major platform beta from a frontier lab; embeds the Codex harness as a service