IndexOpenAI Agent Builder
OpenAI Agent Builder
Agent Builder is the visual editor in the API docs for wiring agents, tools, and handoffs. ChatGPT Agent is the task runner inside the chat app. The names overlap. The products do not.
Updated 2026-09-27
Start at the Agent Builder guide. You need an API account and a key. A Plus subscription does not open the builder. People search “ChatGPT agent builder” and “open AI agent builder” for this same canvas.
What you assemble
- An agent with instructions and a model
- Tools it may call, including your own functions
- Handoffs to a second agent when the job splits
- A preview you run against the API, billed as API usage
The in-app product that browses and clicks for you is ChatGPT Agent. A support-desk workflow is ChatGPT for customer service. Enterprise rollout of many agents is the territory of Frontier.
Questions
Is Agent Builder free?
The canvas is part of the platform. Runs spend API credit. There is no separate Agent Builder subscription in the consumer price list.
Can I build an agent with only ChatGPT Plus?
You can use ChatGPT Agent inside the app. The visual builder and its published workflows use the API.
Related notes
- ChatGPT Agent
ChatGPT Agent works a task inside ChatGPT: it can browse and use tools, then come back with a result. It is not Agent Builder and not a Sponsored Agent.
- OpenAI API and API keys
Create an OpenAI API key at platform.openai.com. Usage is billed apart from ChatGPT Plus. new-api is a separate open-source gateway, not the official API.
- OpenAI chatbot
An OpenAI chatbot is a chat completion loop plus your instructions. Start on the API, keep the key on a server, and add tools only when a reply is not enough.
- OpenAI Frontier
OpenAI Frontier is the enterprise platform for running agents across a company. It is not a ChatGPT Plus feature and not a model name.