# Code Block

> Tabbed code window with line numbers, highlighted lines, a lightweight built-in syntax highlighter (no dependency) and a copy button that confirms. Light and dark friendly.

- Slug: `code-block`
- Category: [Code](https://www.assembli.design/category/code.md)
- Type: component
- Tags: code, syntax, copy, tabs
- npm dependencies: lucide-react, motion
- shadcn/ui dependencies: none
- Added: 2026-10-15
- Live preview: https://www.assembli.design/preview/code-block
- Page: https://www.assembli.design/components/code-block

## 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/code-block/code-block.tsx` and installs dependencies):

```bash
npx shadcn@latest add @assembli/code-block
```

Registry item JSON: https://www.assembli.design/r/code-block.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.