validation

name	validation
description	Schema definition, parsing, and inference patterns using Zod.
paths	["src/lib/validations/**"]

Validation Skill — Zod

Zod is the validation library for this project. Schemas live in src/lib/validations/, exported through src/lib/validations/index.ts.

Define a schema

import { z } from 'zod'

export const userSchema = z.object({
  id: z.string().uuid(),
  email: z.string().email(),
  name: z.string().min(1),
})

export type User = z.infer<typeof userSchema>

Parse vs. safeParse

• schema.parse(input) — throws ZodError on failure (use in API routes inside try/catch)
• schema.safeParse(input) — returns { success, data | error } (use in components)

Reuse via primitives

Common primitives live in src/lib/validations/primitives.ts. Compose feature schemas from primitives to keep validation rules DRY:

import { email, password } from './primitives'
export const loginSchema = z.object({ email, password })

API route validation

import { NextResponse } from 'next/server'
import { z } from 'zod'

const schema = z.object({ name: z.string().min(1) })

export async function POST(request: Request) {
  try {
    const body = await request.json()
    const data = schema.parse(body)
    return NextResponse.json({ data })
  } catch (error) {
    if (error instanceof z.ZodError) {
      return NextResponse.json({ error: error.errors }, { status: 400 })
    }
    return NextResponse.json({ error: 'Internal error' }, { status: 500 })
  }
}

Form integration

When the forms slot uses React Hook Form, wire Zod via @hookform/resolvers/zod. See the forms skill for the full pattern.

Do NOT

• Define schemas inside components — keep them in src/lib/validations/
• Validate the same shape in two places — import from a single source
• Use z.any() — prefer z.unknown() and narrow with refinement