React and generated UI

Captra keeps component implementations in the browser. A remote result carries only an allowed view name and structured data.

Remote execution hook

const refund=useRemoteCapability(client,'refund')
await refund.stream({amount:48})

The hook exposes result, events, pending, and error, plus approve(), reject(), cancel(), refreshEvents(), and reset().

Safe view resolution

<CapabilityOutput result={result} views={{RefundCard}} />

Unknown view names do not dynamically import code. The explicit registry is the security and customization boundary.

UI primitives

• CapabilityBoundary handles pending, error, approval, output, and optional trace states.
• RunStatus renders the current durable run status.
• ApprovalPanel exposes accessible approval controls.
• EventTimeline renders ordered run events.

The primitives are intentionally unstyled and expose stable data-captra attributes.

State hooks

CaptraStateProvider scopes a state instance. useCaptraState() handles loading, subscriptions, deduplication, errors, and refresh. useOptimisticState() returns commit and rollback controls for immediate interfaces.