AUP Web-only widget — not a cross-device primitive; not a Web Device layout component.
The name is registered in AUP_WIDGETS (packages/aup/src/aup-types.ts). It can be accepted by structure verification and implemented by a Web runtime (or native target where noted). It is not one of the 18 cross-device AUP_PRIMITIVES, does not enter DeviceCaps.primitives via fillPrimitives, and is not a Web Device theme/site layout component (for example content-card or page-breadcrumb).
Purpose
Embeds another blocklet page tree into the host tree. Expanded server-side by portal-setup / expandTree; failure is always visible (never blank).
Boundaries
- Do not document this type as a portable primitive.
- Do not mix it with Web Device layout-component reference pages under
widgets/. - A parser-accepted name is not a portability or product-readiness claim.
Author entry
AUP tree type: "blocklet-embed" with target blocklet identity. Not a layout-component.
Surfaces
Interactive Web session after server expansion. Unexpanded client sees unknown type.
Fallback
Expansion error node (visible). No shared degradation chain.
Evidence
| Source | Path |
|---|---|
| Registration | packages/aup/src/aup-types.ts |
| Expansion | providers/runtime/ui/src/portal-setup.ts (blocklet-embed expand path) |
| Path safety | providers/runtime/ui/src/path-safety.ts |
| Tests | providers/runtime/ui/test/blocklet-embed*.test.ts |
Paths are relative to the Arc repository checkout used for this documentation baseline.
Sample
Not docs-safe. Side effects, write paths, native-only surfaces, or trust-sensitive endpoints make a public sample inappropriate. Keep this page as a boundary and evidence index.
Related
- Widgets hub — navigation only
- Primitive taxonomy — 18 vs 42 boundary
- Custom primitives and Web widgets
- Internal matrix:
docs/aup/capability-matrix.md