AUP is ARC’s declarative UI model. An application describes a semantic interface tree, data, and interaction first. Interactive AUP is normally presented by an ARC session and target renderer; Web Device can also render a supported AUP tree directly to static HTML.
Keep three layers distinct:
| Layer | Owns | Does not own |
|---|---|---|
| AUP | The semantic node/event/state/data contract and shared degradation rules | The HTML or native-control implementation for one device |
| AUP DSL | The readable, source-first authoring form and generation tools | A second UI model |
| Device and renderer | Reporting actual DeviceCaps during handshake and implementing presentation and target-side degradation from them | The application’s business intent |
For AUP app configuration, the current loader prefers .aup/app.aup. Only when it is absent does it load .aup/app.json as JSON source; a present but invalid DSL source fails instead of silently falling back. JSON-first apps remain supported, while DSL-first apps can expose or materialize compatible JSON on demand. These are different input/artifact roles for one AUP model, not two products.
Start from the task
| If you need to | Start here |
|---|---|
| Create and run a first complete AUP app | Get started |
| Understand trees, events, sessions, and capabilities | Core concepts |
| Author and maintain source with DSL | Author with DSL |
| Understand how ARC runs it on device surfaces | Run in ARC |
| Inspect source examples and their evidence boundaries | Examples and evidence |
| Look up an exact, versioned contract | Reference |
Relationship to Web Device
Web Device is a Web-facing AUP target: it can statically render supported AUP trees to HTML and lets site pages use AUP to compose Web components. It is not a replacement for an interactive AUP session; a site also has its own .web/ components, pages, themes, content, and routing conventions. Components are one layer for richer HTML, CSS, and interaction on the Web, not the only valid form of an AUP tree.
Site directories, content objects, and themes belong to the Web Device layer and are intentionally outside this AUP board. For AUP semantics, DSL, sessions, or degradation, remain in this board.
Evidence and versions
This board does not treat stale Showcase counts or an unregistered Showcase page file as evidence of a current deployed demo. Implementation semantics are grounded in current source and tests. Its command-bearing pages were run with arc 2.0.0-beta.25; a page that has been filled in identifies its source, test, and runtime boundary. The non-rendered board ledger preserves archaeology and human decisions.