# Introduction
In preparation of the workspace agnostic builder, we're migrating
`FlatEntityMaps` to be universal identifier oriented and based
As in the builder context there're won't be any ids at all
Please also note that the FlatEntity is a UniversalFlatEntity superset
From
```ts
import { type SyncableFlatEntity } from 'src/engine/metadata-modules/flat-entity/types/flat-entity-from.type';
export type FlatEntityMaps<T extends SyncableFlatEntity> = {
byId: Partial<Record<string, T>>;
idByUniversalIdentifier: Partial<Record<string, string>>;
universalIdentifiersByApplicationId: Partial<Record<string, string[]>>;
};
```
To
```ts
export type FlatEntityMaps<
T extends SyncableFlatEntity | UniversalSyncableFlatEntity,
> = {
byUniversalIdentifier: Partial<Record<string, T>>;
universalIdentifierById: Partial<Record<string, string>>;
universalIdentifiersByApplicationId: Partial<Record<string, string[]>>; // this might make more sense to be migrated to universalIdentifiersByApplicationUniversalIdentifier but it's the main topic of this PR
};
```
## Low level maps tools
Had to refactor find | create | delete | replace | find-many | get-sub
tools ( through mutations and or throw equivalent )
