# Page Mapping

Use this reference when the workflow must connect requirements, Pencil pages, and implementation pages.

## Canonical Rule

Treat `page-map.md` as the source of truth for implementation pages.

Treat `design-registry.md` as the source of truth for available `.pen` sources.

Treat `pencil-bindings.md` as the source of truth for:

- implementation page -> Pencil page
- route -> Pencil screen
- shared region -> Pencil region

## Mapping Rules

- define one canonical implementation page name per page
- define one canonical Pencil page or screen per implementation page when possible
- if multiple implementation pages share one Pencil page, record the reason
- if one implementation page needs multiple Pencil screens, record the sub-page or state split

## Minimum Binding Shape

Use a simple mapping line:

```md
- `/settings/billing` -> `Billing Settings Screen`
```

For shared regions:

```md
- `App sidebar` -> `Navigation Shell`
```

## When To Block

Treat bindings as insufficient when:

- no active `.pen` source is registered
- the implementation page has no Pencil source
- the Pencil page exists but cannot be traced to a route or page responsibility
- shared layout regions are undefined and implementation would guess too much

In those cases, stop at the `mapping checkpoint` and update the artifacts.