rich-output

# Rich HTML output The Walnut web console and the iOS app both render raw HTML in an assistant reply as real DOM, streaming it like markdown. You do not need a special syntax or a wrapper: write `<div>`, `<style>`, `<svg>`, `<details>` in the reply and they render. Markdown still works alongside, so use HTML only where it earns its place. **Use it for**: comparisons, flows, step-by-step walkthroughs, anything with state or hierarchy, term highlighting, depth-on-demand. **Skip it for**: a short answer, a code diff, a list of three things. A wall of boxes is worse than a clean paragraph. ## The three rules that matter 1. **No inline `<script>`** — it is routed to a sandboxed iframe (see Islands) or dropped. Interactivity without JS: `<details>`, CSS `:checked` siblings, `:hover`, `@keyframes`. 2. **Your CSS is auto-scoped to your own message.** Every selector in a `<style>` block is rewritten to match only inside that reply, so plain class names (`.card`, `.row`) are safe and cannot restyle the app. `@keyframes` names are rewritten too. `@font-face`, `@property` and `@import` are dropped. 3. **The iOS app renders it too, one small web view per HTML run** — so your `<style>` reaches every run of the same reply, but prose between two cards stays native text (it is not styled), and `<img>` there loads only `data:`/`blob:` sources, so prefer inline `<svg>`. Inline markdown inside an HTML run works on both surfaces (bold, italic, `code`, links), but BLOCK markdown only works on ...