nestjs-api-documentation

# NestJS API Documentation (OpenAPI/Swagger) OpenAPI (formerly Swagger) provides machine-readable API documentation. Good documentation helps clients integrate faster and reduces support burden. ## Why Documentation See `references/why-documentation.md` for the INCORRECT vs CORRECT comparison and the full rationale. --- ## NestJS Swagger Setup ### Module Configuration See `references/swagger-setup.md` (main.ts bootstrap with `DocumentBuilder`) and the interactive docs URLs. --- ## Decorator Reference See `references/decorator-reference.md` for the complete decorator toolkit (controller, request body, parameters, grouping, enums, nested types, class-validator schema). --- ## Custom Response Decorators See `references/custom-response-decorators.md` for the paginated response decorator and the typed error DTO. --- ## Authentication Documentation See `references/auth-documentation.md` for bearer setup, protecting endpoints, and role-based auth. --- ## Anti-Patterns to Avoid See `references/anti-patterns.md` for the four ❌ examples (no error docs, generic descriptions, missing examples, inconsistent docs) with fixes. --- ## Summary: Documentation Responsibilities | Decorator | Purpose | |-----------|---------| | `@ApiTags()` | Group endpoints | | `@ApiOperation()` | Describe operation | | `@ApiBody()` | Request body schema | | `@ApiResponse()` | Response schema | | `@ApiBearerAuth()` | Auth requirements | | `@ApiParam()` | Path parameter | | `@ApiQuery()` | Query parameter | **Golden rule**: If it's not documented, it doesn't exist for clients. Document everything public.