union

union<T extends [Schema<any, any>, ...Schema<any, any>[]]>(
    ...schemas: T,
): UnionSchema<TypeOf<T[number]>, InputOf<T[number]>>

If you want to use a discriminated union, checkout variant

import { x } from 'unhoax'

const schema = x.union(x.string, x.number) // Schema<string | number>
schema.parse('a')
// { success: true, value: 'a' }