---
title: Overview
description: Coordinate temporary application overlays through one API.
order: 1
toc:
  - id: package-role
    title: Package role
  - id: supported-overlays
    title: Supported overlays
  - id: design-boundary
    title: Design boundary
---

## Package role {#package-role}

`@workspace/overlays` is an asynchronous overlay orchestration layer built on Base UI handles and `@workspace/ui`. Application code starts interactions through atomic functions such as `openAlert()` and `openModal()` instead of owning separate `open` state.

Every feature has its own subpath and Host. For example, `@workspace/overlays/modal` contains only the Modal implementation. An `OverlayScope` creates feature channels lazily instead of constructing every Base UI handle up front. Requests of the same kind are queued and never replace a Promise that is still pending.

## Supported overlays {#supported-overlays}

- `alert` waits until a message is acknowledged.
- `confirm` returns `true` or `false`.
- `prompt` returns the entered string, or `null` after cancellation.
- `modal` displays centered custom content.
- `sheet` displays a panel from a page edge.
- `drawer` adds dragging, direction, and snap-point behavior.
- `toast` reuses the Base UI toast manager for notifications, updates, and Promise states.

## Design boundary {#design-boundary}

The package owns scopes, request queues, Promise settlement, and standard structure without duplicating the underlying UI primitives. The root entry exports only scope capabilities; import concrete UI from subpaths such as `/alert`, `/modal`, and `/sheet` to preserve explicit tree-shaking boundaries.