On September 10, 2026, OpenAI took an internal framework it had been refining for years and handed it to every developer with an API key. Currently in public beta, the Agents API exposes the exact same managed harness that keeps long-running agent features in Codex and ChatGPT for Work running for hours - or days - without breaking down. If you have ever tried to build a long-running AI agent, you know the core challenge: getting a model to plan a task is easy. Keeping the execution state, context window, and tool calls intact three hours into an unsupervised job is where most homemade setups fail. Key Takeaways at a Glance Feature Details Core Architecture Bundles Agents, Sessions, Sandboxes, and Tools into a single managed layer. Infrastructure Options OpenAI hosted, Private VPC, or 9 partner sandboxes (Vercel, Cloudflare, E2B, etc.). Pricing Model No harness fee; pay only for standard model tokens and tool usage. Current Hard Blocker US-only data residency; Zero Data Retention (ZDR...
On September 10, 2026, OpenAI took an internal framework it had been refining for years and handed it to every developer with an API key. Currently in public beta, the Agents API exposes the exact same managed harness that keeps long-running agent features in Codex and ChatGPT for Work running for hours - or days - without breaking down. If you have ever tried to build a long-running AI agent, you know the core challenge: getting a model to plan a task is easy. Keeping the execution state, context window, and tool calls intact three hours into an unsupervised job is where most homemade setups fail. Key Takeaways at a Glance Feature Details Core Architecture Bundles Agents, Sessions, Sandboxes, and Tools into a single managed layer. Infrastructure Options OpenAI hosted, Private VPC, or 9 partner sandboxes (Vercel, Cloudflare, E2B, etc.). Pricing Model No harness fee; pay only for standard model tokens and tool usage. Current Hard Blocker US-only data residency; Zero Data Retention (ZDR...