The short answer
Some apps can use AI allowance attached to a supported ChatGPT plan. They must offer a documented sign-in or connection designed for that subscription-backed usage.
The route is app-specific. If an app only asks for an OpenAI API key, its usage is normally handled through separate API billing rather than your ChatGPT subscription. Use My AI Plan lists apps only when a supported subscription route can be documented.
ChatGPT subscription versus OpenAI API billing
ChatGPT plans and the OpenAI API are separate products with separate billing. Paying for ChatGPT Plus or another plan does not turn that subscription into general-purpose API credit.
- ChatGPT subscription
- A recurring plan with included features and usage allowances. Eligible apps can sometimes connect to a supported part of that plan through the sign-in route they document.
- OpenAI API billing
- A separate developer service, commonly connected with an API key and charged according to API usage. A ChatGPT subscription does not automatically pay those charges.
How eligible apps connect
The exact setup differs by app. Some offer a direct ChatGPT sign-in. Others work through an officially supported agent already signed in to your ChatGPT account. The important part is that you deliberately choose the subscription-backed route described on the app page.
- Check compatibility.Confirm that the app supports your exact ChatGPT plan and device.
- Follow the app's setup.Choose its documented ChatGPT or subscription option—not an API-key option—when both are available.
- Review limits and fallbacks.Understand what pauses, resets, or becomes separately billable when the included allowance is reached.
What to check before you connect
- Your exact ChatGPT plan is listed as supported.
- The app runs on the platform you intend to use.
- You know which features use the subscription-backed route.
- You understand the app's own price, if it has one.
- You know what happens when your ChatGPT allowance is exhausted.
- You have not accidentally selected a separate API-key fallback.
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Common questions
- Can I use ChatGPT Plus as an API key?
- No. ChatGPT subscriptions and OpenAI API billing are separate. An eligible app needs its own documented subscription connection.
- Does this mean the other app is free?
- Not necessarily. The app may charge for its software or service even when eligible AI usage comes from your ChatGPT plan.
- Do my normal ChatGPT limits still apply?
- Yes. Supported usage still counts against the applicable plan allowance, and limits can vary by plan, model, and task.
- Why can an app show both ChatGPT and API options?
- Some apps support more than one connection method. Select the documented ChatGPT route if you want eligible usage to come from your plan, and review any fallback before enabling it.