What is ChatGPT Agent Builder? (And what replaces it)

What you get on the canvas

ChatGPT Agent Builder is a drag-and-drop canvas inside OpenAI's developer platform. You drop boxes onto it and join them with arrows: one box searches files you uploaded, one asks the model to decide something, one loops, one stops and waits for a person to approve before the agent acts. There are 11 box types in total, including a guardrail box that watches for personal data and jailbreak attempts. Once the layout works, you publish it as a version and drop it into a chat window on your own site.

Three OpenAI things share the name and get mixed up constantly. A custom GPT is a chatbot you set up inside ChatGPT. Agent mode is ChatGPT going off and doing a task for you. Agent Builder is the canvas where you draw the steps yourself.

It switches off on November 30, 2026

OpenAI announced on June 3, 2026 that it is retiring Agent Builder, roughly a year after launching it at DevDay 2025. Existing workflows keep running until the shutdown date. Guides published in 2025 still walk you through building on it and say nothing about the clock.

What to use instead

OpenAI points to two replacements. One is its code toolkit, which needs an engineer. The other is workspace agents in ChatGPT, which stays no-code but only on Business, Enterprise, Edu and Teachers plans, and free access ended on May 6, 2026. Neither imports your canvas: the diagram, the connected app permissions and the run history stay behind. If something of yours runs on Agent Builder today, budget a rebuild before November rather than a move. If you are picking your first builder this month, pick one that does not already have a published end date.