Base Library

Overview and interactive previews for the unstyled Base prototype library.

Base prescribes no default visual language. It provides testable interaction semantics that can move across hosts. Each card below shows one basic demo for quick browsing; API documentation and code examples stay on the individual prototype pages.

The Base entities currently remain in the draft catalog lifecycle. These previews describe the current official working surface, not a frozen stable API guarantee.

For interactive families, the Base prototype should stop at semantics that are broadly reusable. For dropdown-menu, that boundary is:

• overlay open/close coordination
• collection ordering and item snapshots
• active item, roving focus, and typeahead
• narrow policy surfaces for item commit close and open entry (closeOnItemCommit / closeOnCommit, openEntry / openEntryValue)

It does not, at this layer, define persistent selection, checkbox/radio item semantics, or submenu anatomy. The transient active navigation state is kept internal for now instead of being committed as root API. Those should be composed above base prototypes instead of being precommitted here.

select is the current probe for a slightly different boundary: it still stays protocol-first, but it explicitly keeps a value presentation part inside the family. That part is used to validate Proto UI’s current value-class component path, where selected text is owned by the prototype and refreshed through explicit update-driven re-render instead of being pushed entirely to the host app.

textarea exercises a host-mediated native-control boundary: Root owns one logical multiline editor while its renderer stays contentless, and the adapter selects the physical host target. The current Web profile uses one native textarea across Web Component, React, and Vue. It keeps controlled/uncontrolled ownership stable, normalizes input/change/IME signals, preserves the active editing session, restores unaccepted controlled proposals after composition, and projects properties, focus, and accessibility without claiming form submission, rich text, auto-resize, system editing chrome, or live-region semantics.