zod

The zod skill provides a structured guide to implementing Zod schema validation in TypeScript projects, focusing on type safety, data parsing, and error handling. It addresses common challenges developers face when defining object schemas, applying string and enum validations, handling optional and nullable fields, and ensuring safe input processing. By following these best practices, teams can prevent runtime errors, maintain consistent validation logic, and leverage TypeScript's type system effectively for robust applications.

The skill organizes 43 rules into eight prioritized categories, covering schema definition, parsing and validation, type inference, error handling, object schemas, schema composition, refinements and transforms, and performance optimization. Key features include guidance on using `safeParse` for input validation, distinguishing between `z.input` and `z.infer`, implementing custom error messages, and composing schemas with reusable modules or intersections. Each rule comes with a prefix and priority level to help developers quickly identify high-impact practices, and the guide emphasizes safe handling of JSON, early validation, and proper usage of Zod primitives and coercion techniques.

This skill is primarily targeted at TypeScript developers building applications that require strong runtime validation, including forms, APIs, and complex data structures. It is useful for both writing new schemas and reviewing existing Zod code for consistency and maintainability. Developers who need guidance on handling nested objects, discriminated unions, refinements, and transforms will find this skill particularly valuable. It is not intended for React Hook Form integration or OpenAPI client generation, as separate skills cover those areas.