The short answer
ChatGPT Agent mode is no longer available as a separate feature. OpenAI directs readers to ChatGPT Work for longer, multi-step tasks and finished deliverables. For a production product, the Agents API is a separate developer option—not the former ChatGPT feature embedded in your app. (OpenAI Help Center: ChatGPT agent; Introducing the Agents API)
What changed—and what the terms mean
OpenAI describes Chat as suited to quick, conversational help and Work as an agent for longer tasks and finished deliverables. Work can use a cloud browser for supported website tasks. A custom GPT is different: it is a version of ChatGPT configured for a specific purpose. (ChatGPT Work and Codex; GPTs in ChatGPT)
Older instructions that direct you to “Discover GPTs” or “Create a GPT” describe custom GPTs, not the current Work task flow. (GPTs in ChatGPT)
When ChatGPT Work may fit
Work may suit tasks that involve several steps and leave you with a result to review—for example, comparing product availability, preparing a report from source material, or looking for an available DMV appointment. You could ask it to find an appointment and prepare a booking, but that is an illustrative prompt, not a guarantee that a particular site or booking will work.
OpenAI says Work’s cloud browser can read web pages, click buttons, enter information into forms, and carry out steps on supported public and signed-in websites. What it completes depends on the site, your access, and the task. Review the result and its sources before relying on them. (Using cloud browser in ChatGPT)
If a website requires sign-in, Work pauses and presents a secure sign-in form. Enter your credentials there and complete any requested two-factor authentication; Work can then resume using the signed-in session. (Using cloud browser in ChatGPT)
How to start
- Open OpenAI’s Get started with ChatGPT Work guide for the current entry point. I can’t confirm one exact menu path for both web and mobile, so don’t rely on older “Discover GPTs” instructions.
- Describe the outcome you want, the relevant website or sources, and any constraints.
- If sign-in is required, use the secure sign-in form and complete any requested authentication.
- Follow progress, respond to requests for input or confirmation, and check the result and sources before relying on them.
You do not need to select the cloud browser separately; ChatGPT chooses whether to use it. Cloud-browser availability depends on plan, region, rollout, and workspace permissions. OpenAI’s Help Center says it is available in Work on paid plans in supported regions, excluding Free and Go. (Using cloud browser in ChatGPT)
Building an agent for a production product
For an application or product integration, evaluate developer APIs rather than assuming ChatGPT’s former Agent mode can be embedded. OpenAI describes the Agents API as a separate, beta developer route for building applications with an OpenAI-managed Codex agent that can work across multiple steps and continue in a session. (Agents API beta FAQ; Introducing the Agents API)
Choose a route based on who should manage the agent runtime:
- Agents API: Consider it when you want OpenAI to manage sessions and agent orchestration. The FAQ describes OpenAI-hosted and self-hosted sandbox options. (Agents API overview; Agents API beta FAQ)
- Agents SDK: Consider it when your application should own deployment, tools, state storage, and approval decisions, while the SDK runs the agent loop. (Agents SDK)
- Responses API: Consider it when you want to manage the agent loop directly in your application. (Agents SDK documentation)
There is no universal “best agent model” established by the product name. Define the workflow, permitted tools and data, approval points, and failure conditions first. Then evaluate supported models against representative tasks for correctness, completion, latency, and total cost.
Before choosing the Agents API, account for its current constraints: it is in beta; model requests, OpenAI tools, and OpenAI-hosted sandboxes are billed at their applicable rates; and the API currently supports data residency in the United States only. Check task results and tool outcomes as part of your own evaluation. (Agents API beta FAQ)
Sources
ChatGPT agent — OpenAI Help Center
ChatGPT Work and Codex — OpenAI Help Center
Using cloud browser in ChatGPT — OpenAI Help Center
Get started with ChatGPT Work — ChatGPT Learn
GPTs in ChatGPT — OpenAI Help Center
Agents API (beta) FAQ — OpenAI Help Center