OpenAI Opens the Agents API, a Hosted Codex Harness With No Extra API Fee
On September 10, 2026, OpenAI launched the Agents API public beta: hosted orchestration, long-running sessions, context compaction, and sandboxes (hosted or BYO), billed as tokens plus tools plus containers—no extra API fee. Default examples use GPT-6 Astra. No ZDR.
TLDR
OpenAI on Thursday, September 10, 2026 published “Introducing the Agents API.” Public beta: client.beta.agents.sessions.create. OpenAI runs orchestration, long-running sessions, context compaction, recovery. Hosted sandboxes or BYO (Blaxel, Cloudflare, Daytona, DigitalOcean, E2B, Modal, Oracle, Runloop, Vercel). Multi-agent max_concurrent_subagents. No extra API fee—tokens + tools + container rates. US data residency; no ZDR. Default model examples use gpt-6-astra. Distinct from the April Agents SDK and from ChatGPT Work.
Product-line de-dupe: not Astra chat (Sep 3), not GPT‑Live‑1 API (same day), not ChatGPT for Financial Services (same day). Three Sep 10 product lines.
Why this story matters
OpenAI is productizing the Codex harness as a billable session API. Watch: ZDR still missing, and whether BYO sandbox vendors become the real lock-in.