[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [local‑first/Query](https://evolu.dev/docs/api-reference/common/local-first/Query) › kyselyJsonIdentifier

```ts
const kyselyJsonIdentifier: string & Brand<"Id">;
```

Defined in: [packages/common/src/local-first/Query.ts:348](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/local-first/Query.ts#L348)

A unique identifier prepended to JSON-encoded strings. This allows safe
detection and parsing of only those columns that require JSON.parse.

The identifier is a cryptographically random Evolu Id, ensuring uniqueness
and preventing malicious actors from inserting fake data that could be
misinterpreted as JSON by the application.

Note: The same queries created by different browser tabs will have different
identifiers and thus be considered different and cached separately. This is
usually not a big deal, but if needed, the DB cache can be optimized by
passing the kyselyJsonIdentifier into the DB worker during initialization,
allowing queries to be grouped and recognized across tabs or sessions.

See: https://github.com/kysely-org/kysely/issues/1372#issuecomment-2702773948