ts-validation-schema

When to Use This Skill

Use when you need to:

• Define a data shape that needs both a compile-time type and a runtime check
• Validate a form submission, an API request body, or process.env
• Share one validation rule across client and server instead of duplicating it
• Explain why .parse() crashed a request handler, or why a TS type and actual runtime data have drifted apart

Trigger keywords: Zod, z.object, z.infer, safeParse, parse, schema validation, runtime validation, .extend, .pick, .omit, .merge, discriminated union, env.ts, process.env validation.

Freshness rule: Zod 4 changed error-shape APIs (.flatten()/.format() vs the newer z.treeifyError()) from Zod 3 — check the installed major version before assuming an error-handling shape.