# 5.13 History

> Contract 2.0.0 · package sha256 `a857eca95b35921109faf997094bb4192f12527d9d0fcd4be7e97f06425bad6e` · generated from `examples/section-5/5.13-history.ts` by `services/onsite-scripter/scripts/build-contract-docs.mjs`; edit the source, not this file.

Imports: values (`has`, `validate`, the `Holo*Error` classes, the pure helpers) from `@holostep-configurators/runtime-client`, types from `@holostep-configurators/runtime-client/contract`, `/math` and `/testing` names from those entries; `boot` from the runtime module the root's `loadRuntimeAtFloor` resolves to. A type your page defines is your app's: declare it there, never import it from the package.

```ts
import type { Reason, Session, SessionState } from '@holostep-configurators/runtime-client/contract';
declare const session: Session;
declare const signal: AbortSignal;
declare const fabricGroup: string;                                       // the GroupNode's nodeId
declare function replan(state: SessionState, reason: Reason): Promise<void>;
export async function assistantTurn(): Promise<void> {
  const turn = session.history.group({ label: 'Assistant', actor: 'assistant' });
  try {
    const r = await session.select(fabricGroup, 'velvet-blue', { expectGroup: turn, expectRevision: session.revision });   // actor comes from the group
    if (r.outcome === 'refused') await replan(session.state(), r.reason);   // 'conflict': the shopper clicked; 'busy': a write is pending
  } finally {
    turn.commit();                                                           // also after a refusal: an open group takes the app's next writes until its timeout
  }
}
```

Back to [the examples](README.md) · [llms.txt](../llms.txt)