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# Function seedMockEntityTypes

*   <a id="seedmockentitytypes"></a>
    
    ```typescript
    seedMockEntityTypes(defs: EntityTypeDefinition[]): void
    ```
    
    Types: [EntityTypeDefinition](../interfaces/core.EntityTypeDefinition.md)
    
    Seed the mock entity-type registry from declared types.
    
    The `entities.registerType` RPC is gone; entity types are declared in `.ispo/project.json` (`entityTypes[]`) and registered host-side at adopt/boot. In browser-dev there is no host, so a top-level dev tab seeds its declared types here. This feeds the same `mockEntityTypes` registry that `mockCreateEntity` checks — without a seed, `mockCreateEntity` throws `mock entity type not found`.
    
    Idempotent: re-seeding a type id overwrites the prior definition. Each seed appends a `type-registered` event so watchers in dev see type appearance.
    
    #### Parameters
    
    *   defs: [EntityTypeDefinition](../interfaces/core.EntityTypeDefinition.md)\[\]
    
    #### Returns void