# Spring

> Vitro pack: a coil spring of glass tube wound four and a half times round a tall matte pill, with a glossy ring at each end of the pill. Each turn of the coil slices the pill into its own refracted band. The coil slowly turns and breathes. A tap squashes the spring down and lets it boing back. Raymarched in WebGL.

- Slug: `vitro-spring`
- Category: [Asset packs](https://www.assembli.design/category/asset-packs.md)
- Subcategory: [Vitro](https://www.assembli.design/category/asset-packs/vitro.md) (`vitro`)
- Type: component
- Tags: 3d, webgl, raymarching, asset, glass, abstract, refraction, spring, coil, helix, pill
- npm dependencies: none
- shadcn/ui dependencies: none
- Added: 2026-10-22
- Live preview: https://www.assembli.design/preview/vitro-spring
- Page: https://www.assembli.design/components/vitro-spring

## 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/vitro-spring/vitro-spring.tsx` and installs dependencies):

```bash
npx shadcn@latest add @assembli/vitro-spring
```

Registry item JSON: https://www.assembli.design/r/vitro-spring.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.