OpenAI is shutting down Agent Builder, its visual drag-and-drop tool for building AI agents, on 30 November 2026. The Evals dashboard and API and the reusable prompts feature (the v1/prompts API) are scheduled to shut down on the same day, according to OpenAI's deprecations page. If a chatbot, support assistant or internal workflow at your business was built in Agent Builder, it needs a new home in the next three weeks.
The good news: the parts most live agents depend on are not going away. ChatKit, the toolkit for putting an agent's chat window on your website, remains available, and OpenAI points Agent Builder users to the Agents SDK or ChatGPT Workspace Agents. This guide explains what is stopping, what stays, and a practical plan to move without your customers noticing.
What OpenAI announced
OpenAI notified developers on 3 June 2026 that Agent Builder was being deprecated. The deprecations page now lists three related shutdowns, all set for 30 November 2026:
| What | What happens | OpenAI's suggested replacement |
|---|---|---|
| Agent Builder | Scheduled to shut down on 30 November 2026 | The Agents SDK, or ChatGPT Workspace Agents |
| Evals dashboard and API | Existing evals were set to become read-only on 31 October 2026; full shutdown on 30 November 2026 | Promptfoo, using OpenAI's migration guide |
Reusable prompts (v1/prompts API and prompt objects) |
Scheduled to shut down on 30 November 2026 | Move the prompt text into your own application code |
The Agent Builder guide says existing users can keep using it during the transition window, but OpenAI has not published any extension beyond 30 November. Plan on that date being final.
A short history
Agent Builder was launched as part of AgentKit on 6 October 2025, described by OpenAI as "a visual canvas for creating and versioning multi-agent workflows". It was released in beta, alongside ChatKit and the Connector Registry. That means Agent Builder will have lived for a little over a year. It is the second major OpenAI building block to be retired in 2026: the older Assistants API was sunset on 26 August 2026, with the Responses API as its replacement.
Who is affected
You are affected if any of these are true:
- Your agent's logic lives in Agent Builder. Someone designed the workflow (the boxes and arrows deciding what the agent does next) in OpenAI's visual canvas, and your website or app calls that workflow.
- Your code sends a saved prompt ID instead of the prompt text itself. This is the reusable prompts feature, and it is on the same shutdown list.
- Your team tests the agent's quality in OpenAI Evals. Those test sets and results need to be moved before the dashboard closes.
You are probably not affected if your developer built the agent directly in code with the Responses API or the Agents SDK, or if you only use ChatGPT itself as a staff tool. If you are not sure, ask whoever built the agent one question: "Does anything we run depend on Agent Builder, a saved prompt ID or OpenAI Evals?"
What keeps working
Not everything from the AgentKit launch is being retired, and it is worth being clear so nobody rebuilds more than they need to:
- ChatKit remains available. OpenAI states this directly on the deprecations page. If your website chat window uses ChatKit, the front end can stay; only the workflow behind it needs to move.
- The Agents SDK is the code-based framework OpenAI recommends as the destination for Agent Builder workflows.
- The Responses API is the core API OpenAI recommends for new integrations, and no shutdown date has been announced for it.
Your two migration paths
OpenAI's migration guide explains how to export an Agent Builder workflow and continue with either ChatGPT Workspace Agents or the Agents SDK. One important caveat from that guide: the export does not convert your workflow graph automatically and does not guarantee that every behaviour transfers unchanged. Whichever path you choose, expect some rebuilding and testing.
Path 1: ChatGPT Workspace Agents
This fits agents that are used inside your team, such as an assistant that drafts proposals, answers HR questions or summarises reports. Staff use the agent inside ChatGPT rather than through your own website. It suits businesses that want a low-code option and already pay for ChatGPT for their team.
Path 2: The Agents SDK (in code)
This fits agents that face your customers or connect deeply to your systems: a website support agent, a lead qualification bot, a WhatsApp assistant or an agent that books appointments in your calendar. The workflow becomes normal code that your developers own, version and test. It takes more effort up front but gives you full control.
Should you stay with OpenAI at all?
This is a fair moment to ask. Two OpenAI agent products have now been retired in one year. Keeping your agent's logic in your own code, with the AI model as a swappable component, makes the next change much cheaper, whether that change is a new OpenAI model or a different provider. That is the same lesson we covered in our guide to the GPT-4o API retirement.
A 3-week migration checklist
With 22 days left at the time of writing, here is a realistic plan:
- This week: inventory. List every agent, chatbot and automation that touches OpenAI. Note which use Agent Builder workflows, saved prompt IDs or Evals.
- Export everything now. Use the export described in OpenAI's migration guide for each workflow, and copy every saved prompt's text and settings into a document or your code repository. Do not wait until the last week, as OpenAI does not say whether export will work after shutdown.
- Save your test data. Download Evals datasets and results while you still have access. Do it well before 30 November.
- Choose a path per agent. Internal helpers often suit Workspace Agents; customer-facing agents usually belong in code.
- Rebuild and compare. Run the new version side by side with the old one on 20 to 50 real past conversations. Check answers, tone, tool actions (bookings, CRM updates, emails) and handover to a human.
- Set up testing outside Evals. OpenAI recommends Promptfoo; any repeatable test suite is better than none.
- Switch over by the last full week of November. Leave a few days to fix surprises before the shutdown date, and monitor closely for the first week.
Frequently asked questions
When does OpenAI Agent Builder shut down?
OpenAI's deprecations page lists Agent Builder as scheduled to shut down on 30 November 2026. The Evals dashboard and API and the v1/prompts reusable prompts API are scheduled to shut down on the same date.
Will my ChatKit chat widget stop working?
ChatKit itself remains available, according to OpenAI. However, if the workflow behind your ChatKit widget was built in Agent Builder, that workflow must be moved to the Agents SDK or another backend before 30 November.
What replaces Agent Builder?
OpenAI recommends the Agents SDK for code-based agents or ChatGPT Workspace Agents for agents your team uses inside ChatGPT. Its migration guide notes that exported workflows may not behave exactly the same, so test before switching.
Is this a good time to switch AI providers?
It can be. If you are rebuilding anyway, structuring the agent so the AI model can be swapped keeps you flexible. Compare quality and cost on your own real conversations rather than on benchmarks.
The bottom line
If any part of your business runs on Agent Builder, saved prompts or OpenAI Evals, treat 30 November 2026 as a hard deadline: export this week, choose a path for each agent, and switch over with time to spare. Done well, the move is also a chance to make your agent more reliable and less tied to any one vendor. If you would like us to audit your setup or handle the migration, see our AI agents service, read our guide to AI agents for business, or get in touch.