​
Overview

Schemas package contains data schemas for the applications, including resource schemas. Data schema — is a Zod schema that defines shape of the entity. It must strictly define all fields. Resource schema is defined in entity.schema file e.x. user.schema. 
import { z } from 'zod';

import dbSchema from './db.schema';

const schema = dbSchema.extend({
  firstName: z.string(),
  lastName: z.string(),
  fullName: z.string(),

  email: z.string(),
  passwordHash: z.string().nullable().optional(),

  isEmailVerified: z.boolean().default(false),

  signupToken: z.string().nullable().optional(),
  resetPasswordToken: z.string().nullable().optional(),

  avatarUrl: z.string().nullable().optional(),
  oauth: z.object({
    google: z.boolean().default(false),
  }).optional(),

  lastRequest: z.date().optional(),
}).strict();

export default schema;

​
Validation

Zod schemas simplify form validation in react-hook-form: 
import { z } from 'zod';
import { useForm } from 'react-hook-form';
import { zodResolver } from '@hookform/resolvers/zod';

import { EMAIL_REGEX, PASSWORD_REGEX } from 'app-constants';

const schema = z.object({
  firstName: z.string().min(1, 'Please enter First name').max(100),
  lastName: z.string().min(1, 'Please enter Last name').max(100),
  email: z.string().regex(EMAIL_REGEX, 'Email format is incorrect.'),
  password: z.string().regex(PASSWORD_REGEX, 'The password must contain 6 or more characters with at least one letter (a-z) and one number (0-9).'),
});

type SignUpParams = z.infer<typeof schema>

const SignUp = () => {
    const methods = useForm<SignUpParams>({
        resolver: zodResolver(schema),
    });

    return (
        //your code here
    )
}

export default SignUp;
Additionally, data can be validated using the saveParse method: 
const parsed = zodSchema.saveParse(data);

if (!parsed.success) {
    throw new Error('Invalid data');
}
For more details on Zod, check the documentation.