# Native and artifact delivery (beta)

Both React/Svelte native targets and precompiled publication artifacts receive the same island input:

```json
{
  "inputVersion": 1,
  "block": {
    "id": "authored-block",
    "type": "example:scene",
    "schemaVersion": 1,
    "contract": { "id": "<immutable contract ID>", "digest": "<digest>" }
  },
  "activation": "visible",
  "payload": null,
  "initialState": { "selected": 0 },
  "accessibility": { "label": "Example scene" }
}
```

`payload` is any JSON value, including arrays, strings, numbers, booleans and null; it MUST NOT be flattened or replaced with an empty object. Contract identity is present when source is locked. Content, fallback, accessibility, readable associations and optional `initialState` retain their authored structure. Services, executable loaders, DOM targets and lifecycle handles stay out of band. This is an atomic frozen-beta ABI update; there is no reader-side legacy interpretation branch. Incompatible artifact/input versions preserve fallback and receive explicit incompatibility markers.

## Artifact versus native fidelity

Artifacts contain an HTML fragment, stylesheet and module identifiers, used island inputs, compatibility/static-fidelity report, diagnostics, output identity and optional reproducibility provenance. They are not framework templates or executable module mappings. Hosts separately approve implementation IDs and URLs; document-provided module-like strings do not execute themselves. `publicationReaderManifest` extracts only format, version, identity, compatibility and islands for attachment, avoiding duplication of SSR HTML, resources, diagnostics or source AST in browser data. The `publication-runtime` entry excludes schema validators, compiler, registry and formatter tooling.

| Capability                         | Native target                    | Publication artifact                                                  |
| ---------------------------------- | -------------------------------- | --------------------------------------------------------------------- |
| Core static blocks and math        | Direct target output             | Precompiled HTML                                                      |
| Host static framework component    | Host component                   | Host-approved `lower(input)` nodes or substantive authored fallback   |
| Interactive host implementation    | Approved module and common input | Approved ID mapping and the same input                                |
| Unsupported static component       | Host responsibility              | Error and `staticFidelity: unsupported`; no empty success placeholder |
| Missing/failed implementation      | Preserve fallback                | Preserve fallback                                                     |
| Trusted authored raw HTML with IDs | Host markup policy               | Reject by default, or explicit restricted-placement preservation      |

Static lowering/fallback is reported and is not a promise of arbitrary framework visual equivalence. Used modules/styles are deduplicated. Payloads and declared datasets are not unsafely pruned merely because a renderer appears not to read them. No full source AST/schema/registry is delivered solely for rendering. Three.js, Mermaid and other computation engines remain host-side implementations.

## Placement and CSS policy

Compiler-generated IDs, fragment links, label/form associations and ARIA token references are namespaced per placement. Hosts supply a unique instance ID matching `[A-Za-z][A-Za-z0-9_-]{0,63}`. Generated React/Svelte targets use framework-owned IDs when a host does not supply one. Repeated placements do not share interactive state. Compiler-generated CSS is rooted under Publisle classes; approved components/styles remain the host's responsibility. Arbitrary authored trusted HTML cannot be generically rewritten into safe scoped markup; artifact compilation rejects identity-bearing raw HTML by default. `rawHtmlPlacement: preserve` produces a warning and requires host restrictions.

Hosts remain responsible for sanitization, CSP, stylesheet/asset origins and internal component IDs. Raw HTML opt-in is not a sanitizer. Browser acceptance verifies native/artifact JSON input parity, repeated ID/reference behavior, independent state and the absence of preparation tooling from readers. It does not claim a universal CSS reset or numerical equivalence of user engines.

## Lifecycle and activation

`createIslandController` is the framework-independent browser lifecycle. React and Svelte leaf adapters, and artifact `attachPublication`, call it. A small vanilla host can call it directly. There is no separate reader ABI version; `inputVersion` and the publication format remain 1. `hydrate` stays unsupported and is marked `data-publisle-unsupported-mode` rather than partially applied.

| Activation    | Behavior                                                                                        |
| ------------- | ----------------------------------------------------------------------------------------------- |
| `load`        | Mount during controller setup                                                                   |
| `visible`     | Mount when the scope intersects the viewport; without `IntersectionObserver`, mount immediately |
| `idle`        | Mount from `requestIdleCallback`, or on the next turn when it is absent                         |
| `interaction` | Mount from click, Enter, or Space on `[data-publisle-activate]`                                 |

The first gesture only activates. It does not replay the browser event and it does not invoke a named semantic action. `props` stay the authored island input.

`load` receives an `AbortSignal`. `destroy` aborts that signal, ignores a late result, and unmounts at most once. A second `activate` while a mount is pending or complete does not mount again. A failed load keeps the activate control available for retry, leaves the fallback visible, marks `data-publisle-status="failed"`, and moves focus back to the activate control. A successful load moves focus from that control to the mount root and marks `data-publisle-status="ready"`. During the load the scope is `aria-busy="true"`. That status is not an invented description of the output. Hosts announce meaningful output changes themselves.

Implementations load on activation. Repeated placements share a module load and keep independent mounts; rejected imports are cleared so another activation can retry. Optional `suspend: true` cancels pending loads or unmounts a `visible` island that leaves the viewport and mounts it again on return. Suspension is off unless the host opts in. When `prefers-reduced-motion: reduce` matches, idle activation runs immediately and publication CSS disables animation and transitions on interactive regions. Print CSS hides the activate control and the mount root and shows the authored fallback. A locked contract id and digest are copied onto `data-publisle-contract` on native/artifact boundaries and the explanatory region, including when a renderer is missing. That attribute records provenance; it does not make a snapshot the editable source.

Pointer-only host canvases still have to expose this keyboard activate control or another documented keyboard alternative, plus the authored instructions. These checks do not claim WCAG conformance.