global-validation
Implement comprehensive input validation with server-side validation (security), client-side validation (UX), fail-early patterns (KISS), specific error messages, allowlists over blocklists, and reusable validators (DRY). Use this skill when validating user input in forms, API endpoints, or data processing functions. Use when implementing validation rules for data types, formats, ranges, required fields, or business rules (SRP). Use when creating validator functions, validation schemas (Zod, Joi, Yup), form validation logic, or input sanitization to prevent injection attacks (SQL, XSS). Use when working with backend validators, frontend form libraries (React Hook Form, Formik), or consistent validation across web forms, API endpoints, and background jobs. Apply validation at multiple layers for defense in depth.
When & Why to Use This Skill
This Claude skill provides a comprehensive framework for implementing robust input validation across the full technology stack. It prioritizes security through server-side defense-in-depth and enhances user experience with immediate client-side feedback. By leveraging industry-standard patterns like DRY, KISS, and SRP, and integrating with modern libraries such as Zod, Joi, and React Hook Form, it helps developers prevent injection attacks and ensure data integrity throughout the application lifecycle.
Use Cases
- Securing API endpoints by implementing strict schema-based validation to reject invalid data before it reaches the business logic.
- Enhancing frontend UX by creating real-time form validation with specific, actionable error messages using libraries like Formik or React Hook Form.
- Preventing security vulnerabilities such as SQL injection and XSS by applying allowlist-based sanitization and multi-layer validation patterns.
- Standardizing data processing workflows by creating reusable validator functions and schemas that maintain consistency between backend services and background jobs.
| name | Global Validation |
|---|---|
| description | Implement comprehensive input validation with server-side validation (security), client-side validation (UX), fail-early patterns (KISS), specific error messages, allowlists over blocklists, and reusable validators (DRY). Use this skill when validating user input in forms, API endpoints, or data processing functions. Use when implementing validation rules for data types, formats, ranges, required fields, or business rules (SRP). Use when creating validator functions, validation schemas (Zod, Joi, Yup), form validation logic, or input sanitization to prevent injection attacks (SQL, XSS). Use when working with backend validators, frontend form libraries (React Hook Form, Formik), or consistent validation across web forms, API endpoints, and background jobs. Apply validation at multiple layers for defense in depth. |
Global Validation
This Skill provides Claude Code with specific guidance on input validation best practices across backend and frontend, including KISS, SRP, and DRY principles.
When to use this skill
- When implementing input validation for user-submitted data
- When validating data in API endpoints, controllers, or route handlers
- When creating form validation logic in frontend components
- When writing validation schemas (Zod, Joi, Yup, class-validator)
- When validating data types, formats, ranges, or required fields
- When implementing business rule validation at appropriate application layers (SRP)
- When creating reusable validator functions or classes (DRY)
- When sanitizing user input to prevent injection attacks (SQL, XSS, command injection)
- When failing early and rejecting invalid data before processing (KISS)
- When providing clear, field-specific error messages to users
- When using allowlists instead of blocklists for input validation
- When ensuring consistent validation across all entry points (web forms, API, background jobs)
- When working with form libraries (React Hook Form, Formik, Angular Forms)
- When implementing server-side validation for security and client-side for UX
Instructions
For details, refer to the information provided in this file: global validation