# `IGroupNode.defaultNodeId`

> Contract 2.0.0 · package sha256 `a857eca95b35921109faf997094bb4192f12527d9d0fcd4be7e97f06425bad6e` · generated from `configurator-runtime.d.ts` by `services/onsite-scripter/scripts/build-contract-docs.mjs`; edit the source, not this file.

Property of [`IGroupNode`](IGroupNode.md) · inherited by [`ConfiguratorNode`](ConfiguratorNode.md) · stable · since 2.0.0

```ts
defaultNodeId?: string;
```

The selected child's [`nodeId`](IConfiguratorNode.nodeId.md) (for a global-material group, the selected MaterialNode, which places nothing). Absent or null: every enabled child is placed; any string, '' included, places only the child it names, so a stored one naming no child places none (spec section 6.9, ID10). Written through [`applyPatch`](Writer.applyPatch.md) at `/model/node/{id}/defaultNodeId`, a non-empty value names a child once the patch has run, or the call rejects HoloInputError 'unknown-id' with the children as `didYouMean`; null and '' still write.

**Default:** undefined (every enabled child)

## Generic-API test (spec 3.1)

| Rule | Result |
| --- | --- |
| 1. Neutral name | pass: `defaultNodeId` names no product |
| 2. A precedent | not recorded: no ledger row (coverage.json) names this member or its owner |
| 3. Two apps, or labs | not recorded: no ledger row names this member or its owner |
| 4. The cheaper fix first | not recorded per member (Appendix B decides it per need) |