zod

Use safeParse() instead of parse() for user input so validation failures return a result object instead of throwing exceptions. Check result.success, then read result.error.issues or result.error.flatten() to display field-level errors.

z.any() bypasses TypeScript's type system entirely, while z.unknown() accepts any value but forces type narrowing before use. Prefer z.unknown() to preserve type safety when the input shape is not yet known.

Use parseAsync() or safeParseAsync() whenever a schema includes async refine or transform functions, such as database lookups. Calling synchronous parse() with async refinements throws an error at runtime.

Call .partial() on the base schema to make all fields optional, which keeps the update schema in sync automatically. Use .pick() and .omit() to derive variants like public views or create inputs without duplicating field definitions.

Yes, use z.lazy() with an explicit TypeScript type annotation to define self-referential schemas such as trees, nested comments, or arbitrary JSON. Direct self-reference without z.lazy() fails because the variable is used before declaration.

Use Zod Mini for bundle-sensitive frontend applications where size matters; it is about 1.9kb gzipped versus roughly 17kb for full Zod. The tradeoff is a reduced API surface, so verify the methods you need are included.