Meet the ChatGPT Apps SDK UI design and security requirements so an app passes review

Documented steps

1. Build with the Apps SDK UI design system (`@openai/apps-sdk-ui`, Tailwind styling foundations, CSS-variable design tokens) so the widget matches ChatGPT's native design language.
2. For inline cards: limit to two actions placed at the bottom, avoid deep navigation or multiple views, and let cards auto-fit content with no internal scrolling.
3. For carousels: keep 3-8 items, at most three lines of metadata text, and one optional call-to-action per card.
4. Use system colors for text, icons, and dividers; restrict brand accent color to primary buttons and badges, and never redefine core system colors.
5. Inherit the system font stack (SF Pro on iOS, Roboto on Android) — custom fonts are prohibited, including in fullscreen mode; and omit your logo from the response, since ChatGPT appends it automatically.
6. Meet accessibility requirements: WCAG AA minimum contrast between text and background, alt text on all images, and layouts that survive text resizing.
7. Apply data minimization and least privilege: include only the data the current prompt requires, request only necessary scopes, validate all inputs server-side, and require human confirmation for irreversible writes.
8. Official docs: https://developers.openai.com/apps-sdk/concepts/ui-guidelines and https://developers.openai.com/apps-sdk/guides/security-privacy