Zod + Viem

address-validator.ts

import { getAddress } from 'viem'
import { z } from 'zod'

export const address = z
  .string()
  .transform((val, ctx) => {
    try {
      return getAddress(val.toLowerCase())
    } catch {
      ctx.addIssue({
        code: z.ZodIssueCode.custom,
        message: 'Not a valid address',
      })
      return z.NEVER
    }
  })
  .brand('Address')

export type Address = z.infer<typeof address>