[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [Lookup](https://evolu.dev/docs/api-reference/common/Lookup) › StructuralLookupKey

```ts
type StructuralLookupKey = string & Brand<"StructuralLookupKey">;
```

Defined in: [packages/common/src/Lookup.ts:240](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/Lookup.ts#L240)

Branded native key produced by [structuralLookup](https://evolu.dev/docs/api-reference/common/Lookup/functions/structuralLookup).