# Stack

> Optic pack: two thick square slabs of optical glass, one resting off-center on the other. Their color pools deep in the middle and thins to clear, crisp rims, the edges split light into thin rainbow fringes, and they float over a soft tinted shadow. The top slab drifts in a slow circle; a tap gives it a quarter turn. Raymarched in WebGL.

- Slug: `optic-stack`
- Category: [Asset packs](https://www.assembli.design/category/asset-packs.md)
- Subcategory: [Optic](https://www.assembli.design/category/asset-packs/optic.md) (`optic`)
- Type: component
- Tags: 3d, webgl, raymarching, asset, glass, refraction, dispersion, slabs, stack, blocks, squares
- npm dependencies: none
- shadcn/ui dependencies: none
- Added: 2026-10-24
- Live preview: https://www.assembli.design/preview/optic-stack
- Page: https://www.assembli.design/components/optic-stack

## 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/optic-stack/optic-stack.tsx` and installs dependencies):

```bash
npx shadcn@latest add @assembli/optic-stack
```

Registry item JSON: https://www.assembli.design/r/optic-stack.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.