Response Envelope Enforcer

Overview

This skill validates and enforces consistent StandardSuccessResponse wrapping patterns across your app NestJS API, ensuring frontend-backend contract alignment and preventing response structure inconsistencies that cause data extraction failures.

Core Principle: All HTTP API endpoints must return responses wrapped in StandardSuccessResponse format { success: true, data: T, metadata?: ResponseMetadata }. Different response types require different handling approaches.

Problem Context

Common Issue: Controllers return data directly without wrapping in the standard API response envelope. The frontend's BaseApiService expects { success: true, data: [...] } and tries to extract the data field, but receives a raw array instead, causing extraction failures.

Root Causes:

• Controllers use different wrapping strategies without documentation
• Some explicitly wrap with new StandardSuccessResponse(data)
• Some return raw data relying on ResponseTransformInterceptor
• Special cases (WebSocket, binary files) mixed with HTTP patterns
• DTOs confused with response wrappers