# Grass Arc Hero

> Airy hero where a furry grass hillside rises in an arc across a blue sky and fills the bottom of the frame, dotted with daisies. Over 200,000 instanced blades lean, sway in the wind and lie down wherever the pointer brushes them, then slowly stand back up. Italic serif over a tight sans headline, a glass pill nav, and a moonlit version in dark mode. Raw WebGL, no three.js.

- Slug: `grass-arc-hero`
- Category: [Heroes](https://www.assembli.design/category/heroes.md)
- Type: block
- Tags: 3d, webgl, grass, nature, interactive, instancing, sky
- npm dependencies: motion, lucide-react
- shadcn/ui dependencies: none
- Added: 2026-10-17
- Live preview: https://www.assembli.design/preview/grass-arc-hero
- Page: https://www.assembli.design/components/grass-arc-hero

## Install

One-time setup (needs a subscription):

1. Add the registry to the project's `components.json`: `{"@assembli":{"url":"https://www.assembli.design/r/{name}.json","headers":{"Authorization":"Bearer ${ASSEMBLI_API_KEY}"}}}` (merge into `"registries"`).
2. Put an API key from https://www.assembli.design/account in `.env.local` as `ASSEMBLI_API_KEY=asm_…`.

Then install with the shadcn CLI (writes `components/grass-arc-hero/grass-arc-hero.tsx` and installs dependencies):

```bash
npx shadcn@latest add @assembli/grass-arc-hero
```

Registry item JSON: https://www.assembli.design/r/grass-arc-hero.json (send `Authorization: Bearer <api key>`)

## Code

> Component source needs an Assembli subscription ($12/month) and an API key sent as `Authorization: Bearer <key>`. To get one without copying anything, POST https://www.assembli.design/api/agent/login (or call the MCP tool connect_account), show the user the link it returns, and poll https://www.assembli.design/api/agent/token for the key. Or subscribe at https://www.assembli.design/pricing and create a key at https://www.assembli.design/account.