backend-api-responses

Structure API responses with consistent envelopes, appropriate HTTP status codes, and standardized error formats. Use this skill when implementing response handlers, formatting API response data, creating error response structures, implementing validation error responses, setting up pagination response formats, defining response DTOs or serializers, implementing HTTP status code logic, creating response middleware or interceptors, formatting success and error response envelopes, sanitizing response data to prevent sensitive data leakage, implementing field-level validation error responses, or working with response transformation logic. Use when writing controller return statements, response serializers, error handlers, or any code that formats and returns data to API clients.