NestJS API Standards & Common Patterns

Priority: P1 (OPERATIONAL)

Workflow: Standardize API Endpoint

1. Create Response DTO — Define dedicated DTO for every endpoint return type.
2. Map entity to DTO — Use plainToInstance(UserResponseDto, user) in service or controller.
3. Apply TransformInterceptor — Bind globally to wrap all responses in { statusCode, data, meta }.
4. Add nested validation — Decorate nested DTO properties with @ValidateNested() + @Type().
5. Document with Swagger — Apply @ApiResponse({ status, type }) with exact types per endpoint.

Response Wrapper Example

See implementation examples

Entity-to-DTO Mapping Example

See implementation examples