OpenAI Assistants API to Responses API: Complete Migration Guide (openai assistants api migration responses api)
If you are shipping on OpenAI Assistants API, migrate now because the platform has a fixed retirement timeline and the migration is an architecture rewrite, not a search-and-replace. The official deprecation notice was published with a one-year runway, so the hard part is usually your state model and tool integration, not endpoint syntax. In practice, you should move in phases: map resources, move prompts, manage history explicitly, and then harden observability before the 2026 shutdown. ...