# Rail Sidebar

> Analytics sidebar that collapses to an icon rail with ⌘B. When collapsed, a single tooltip glides between icons, and the Realtime item counts live visitors. Has a site switcher and a user footer.

- Slug: `rail-sidebar`
- Category: [Sidebars](https://www.assembli.design/category/sidebars.md)
- Type: block
- Tags: collapse, icons, rail, analytics
- npm dependencies: motion, lucide-react
- shadcn/ui dependencies: none
- Added: 2026-10-22
- Live preview: https://www.assembli.design/preview/rail-sidebar
- Page: https://www.assembli.design/components/rail-sidebar

## 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/rail-sidebar/rail-sidebar.tsx` and installs dependencies):

```bash
npx shadcn@latest add @assembli/rail-sidebar
```

Registry item JSON: https://www.assembli.design/r/rail-sidebar.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.