openai shuts down the assistants api

what happened

• OpenAI's API changelog states: 'The Assistants API shut down on August 26, 2026.'[1]
• OpenAI's deprecations page says developers were notified in August 2025 that the Assistants API would be removed one year later, with the Responses API and Conversations API as its replacement.[2]
• OpenAI's migration guide maps Assistants to Prompts, Threads to Conversations, Runs to Responses, and Run steps to Items.[3]
• The guide says the Assistants call that retrieved thread messages no longer works, and tells developers to rebuild conversation history from their own stored messages.[3]
• Prompts, which replace assistants, can only be created in the dashboard, and the guide warns that reusable prompt objects are themselves being deprecated; OpenAI's deprecations page schedules the v1/prompts API and reusable prompt objects to shut down on November 30, 2026.[3,2]
• OpenAI has also scheduled Agent Builder and the Evals platform for shutdown on November 30, 2026 (announced June 3, 2026), with existing evals becoming read-only on October 31, 2026.[2]