> ## Documentation Index
> Fetch the complete documentation index at: https://developers.usezend.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Designing for the screen

> How Zend frames your app on mobile and web, and how to fit in.

Zend opens your app full screen.

> [tab] Mobile
>
> * A WebView with no URL bar or browser chrome.
> * Zend shows your icon and name while you load.
> * The status bar matches your page's `body` background colour.
> * Zoom and link callouts are off.
> * One small floating pill (top right, collapses to a dot, draggable) gives the user **Close** and **Report**.
> * Android back goes back through your pages first.

> [tab] Web
>
> * The address bar shows `app.usezend.app/apps/<slug>`.
> * Your app fills the window under a slim Zend bar.
> * The browser's back button returns to Zend.

Unreviewed apps show "Made by {you}. Not checked by Zend." on the loading screen and in the menu.

## Guidelines

* Build for full screen, mobile first. Set a solid `body` background colour.
* Keep the top-right 120×44 px clear of important controls. The Zend pill sits there until it folds.
* Don't add your own "back to Zend" button. Call `zend.close()` when you're done; the optional result goes back to whatever opened you.
* Links to other sites open outside Zend after the user confirms. Keep everything you need on your own origins.
* Users find you on Discover by name. Use your real app name in `name` and a one-line `description`.
* Let users report problems with `zend.report({ reason, detail?, interactionId?, prizeId? })`. Reasons: `scam`, `unfair_result`, `offensive`, `broken`, `other`.

## Hosting headers

Zend loads your page in a frame on the web. If you send a `Content-Security-Policy`, allow Zend as a frame ancestor:

```text theme={null}
Content-Security-Policy: frame-ancestors https://app.usezend.app
```

Public apps also serve `/.well-known/zend-app.json` on every origin. See [Public apps](https://developers.usezend.app/ship/public-apps.md#prove-you-own-your-origins).


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