What's the difference between “Enhance prompt” and Auto-prompt?

“Enhance prompt” polishes the wording of what you already wrote with architectural vocabulary, at a similar length and without adding new elements. It's in Canvas AI (the sparkle button in the instructions) and in AI Chat (the “Enhance” button), it's free and it's on every plan.

Auto-prompt does something else: it looks at your base image and writes a complete prompt — style, materials, light and composition — after asking you for the time of day and the weather. It appears when the instructions are empty (in Canvas AI, “Auto-generate prompt from image”; in the chat, “Auto-prompt”), and in Nodes the Image scanner and the Text node's “Analyze connected image” do it. It costs no tokens and it's for paid plans.