The sandbox

Your page runs in a locked-down frame with a strict Content Security Policy. Anything outside the SDK fails or is blocked.

No inline scripts and no eval or new Function. Ship scripts as files. Bundlers are fine. With Vite, keep base: "./".
No network. fetch, XMLHttpRequest and WebSockets are blocked. Use notch.net.fetch with the network permission.
No localStorage, IndexedDB or cookies. Use notch.storage.
No remote code or assets. Scripts, styles, images and fonts load only from your own package. Bundle fonts as woff2.
No navigation or popups. A frame that navigates away is stopped and restarted. Open links with notch.openUrl.
Transparent page. The host draws the tile and its header (your plugin’s name). Don’t paint a full background or a title.
Short-lived. Frames exist only while the panel is open and start after its opening animation. Load fast, and save state as you go.
No continuous animation. Animate only in response to something, and stop when visibility is false.

Views

Your entry page loads with a view query parameter. The same value is in ctx.view and in <html data-view>.

`view`	When
`tile`	On the board, at the widget’s size.
`expanded`	The full panel, after `notch.openExpanded()`. Needs `widget.expanded`.
`service`	Hidden, to answer calls to services you `provides`.

Reviewers

Reviewers read your code. Ship readable source or source maps. Obfuscated code is rejected. Expect questions about eval, attempts at direct network calls, and minified bundles without maps.