OpenAI has opened public beta access to Agents API. Agents API is a service for building and running cloud agents on the Codex harness, which OpenAI fully manages.

The Codex harness is the software environment that manages context, uses tools, and coordinates subagents. Developers choose the agent’s execution environment: an OpenAI sandbox, their own infrastructure, or a partner environment.

Vercel describes hosting the agent experience on its platform and connecting each session to Vercel Sandbox, an isolated execution environment, for code execution and file access. In this setup, OpenAI manages the agent’s work and maintains session state.

Claim check:

  • OpenAI has opened public beta access to Agents API. (confirmed by the publication itself: evidence; «Today, we’re introducing the Agents API ⁠ (opens in a new window) in public beta, bringing that same harness and infrastructure that powers Codex to developers through a simple, flexible API.»)
  • Agents API builds and runs cloud agents on the Codex harness, which OpenAI fully manages. (confirmed by the publication itself: evidence; «Build and run cloud agents with the Codex harness, fully managed by OpenAI.»)
  • The Codex harness manages context, uses tools, and coordinates subagents. (confirmed by the publication itself: evidence; «Useful agents need a powerful harness that manages context, uses tools efficiently, and coordinates subagents.»)
  • Developers choose the agent’s execution environment: an OpenAI sandbox, their own infrastructure, or a partner environment. (confirmed by the publication itself: evidence; «OpenAI hosts and maintains the harness. You choose the agent’s compute environment: in an OpenAI-managed sandbox, on your own infrastructure, or with one of our sandbox partners.»)
  • Vercel describes hosting the agent experience on its platform and connecting each session to Vercel Sandbox for code execution and file access. (confirmed by the publication itself: evidence; «You can host the agent experience on Vercel and connect each session to Vercel Sandbox for code execution and file access.»)
  • OpenAI manages the agent’s work and maintains session state. (confirmed by the publication itself: evidence; «OpenAI runs the agent loop and maintains session state.»)

Primary sources:

score 87.3 out of 100 · kind: announcement · update 2