OpenAI Agent Builder and Evals Winddown Migration Checklist

OpenAI's Agent Builder and Evals winddown turns a product update into a practical migration problem. Teams that used visual agent flows, dashboard evals, prompt optimizers, datasets, graders, or release gates now need to decide what should move to code, what belongs in ChatGPT Workspace Agents, what should be retired, and what evidence must be captured before access changes. OpenAI's AgentKit announcement now carries a June 3, 2026 update saying Agent Builder and Evals will no longer be availab...