⚠️ If document.modelContext is undefined, check these in order.
① In ChatGPT, Settings > Browser > Permissions — is Enable site tools on?
② Is your model GPT-5.6 Sol or Terra? (disabled on Luna)
③ Is your workspace not Enterprise / Edu? (excluded)
④ It is a staged rollout — it may not have reached your account yet.
If you are inside an iframe ("top-level" shows ✗ above), it is not supported at all.
How to use. Open this page in the ChatGPT desktop app's built-in browser,
turn on Enable site tools under Settings > Browser > Permissions,
then ask it something like "draw a cat on this canvas".
If AI rows appear in the log on the right, it is calling the tools.
You can draw with the mouse at any time, even while it is drawing. Barge in.