Validation (Zod + Guards)

Consistent validation at boundaries: Zod for complex schemas, small guards for simple runtime checks.

When to Use

Use this skill when:

• Validating API responses or external data in services
• Validating request/input shapes at boundaries (e.g. route handlers, SDK)
• Adding or refactoring utils/validation/ helpers
• Defining Zod schemas alongside types in types/<area>/

Non-Negotiables (MUST)