Custom validation

You can add runtime validation for your user input for Prisma Client queries in one of the following ways:

• Prisma Client extensions
• A custom function

You can use any validation library you'd like. The Node.js ecosystem offers a number of high-quality, easy-to-use validation libraries to choose from including: joi, validator.js, Yup, Zod and Superstruct.

Input validation with Prisma Client extensions

Prisma Client extensions are currently in Preview.

This example adds runtime validation when creating and updating values using a Zod schema to check that the data passed to Prisma Client is valid.

import { PrismaClient, Prisma } from "@prisma/client";
import { z } from 'zod'

/**
 * Zod schema
 */
export const ProductCreateInput = z.object({
  slug: z
    .string()
    .max(100)
    .regex(/^[a-z0-9]+(?:-[a-z0-9]+)*$/),
  name: z.string().max(100),
  description: z.string().max(1000),
  price: z
    .instanceof(Prisma.Decimal)
    .refine((price) => price.gte("0.01") && price.lt("1000000.00")),
}) satisfies z.Schema<Prisma.ProductUncheckedCreateInput>;

/**
 * Prisma Client Extension
 */
const prisma = new PrismaClient().$extends({
  query: {
    product: {
      create({ args, query }) {
        args.data = ProductCreateInput.parse(args.data);
        return query(args);
      },
      update({ args, query }) {
        args.data = ProductCreateInput.partial().parse(args.data);
        return query(args);
      },
      updateMany({ args, query }) {
        args.data = ProductCreateInput.partial().parse(args.data);
        return query(args);
      },
      upsert({ args, query }) {
        args.create = ProductCreateInput.parse(args.create);
        args.update = ProductCreateInput.partial().parse(args.update);
        return query(args);
      },
    },
  },
});

async function main (){
  /**
   * Example usage
   */
  // Valid product
  const product = await prisma.product.create({
    data: {
      slug: "example-product",
      name: "Example Product",
      description: "Lorem ipsum dolor sit amet",
      price: new Prisma.Decimal("10.95"),
    },
  });

  // Invalid product
  try {
    await prisma.product.create({
      data: {
        slug: "invalid-product",
        name: "Invalid Product",
        description: "Lorem ipsum dolor sit amet",
        price: new Prisma.Decimal("-1.00"),
      },
    });
  } catch (err: any) {
    console.log(err?.cause?.issues);
  }
}

main()

The above example uses a Zod schema to validate and parse data provided in a query at runtime before a record is written to the database.

Input validation with a custom validation function

Here's an example using Superstruct to validate that the data needed to signup a new user is correct:

import { PrismaClient, Prisma, User } from '@prisma/client'
import { assert, object, string, size, refine } from 'superstruct'
import isEmail from 'isemail'

const prisma = new PrismaClient()

// Runtime validation
const Signup = object({
  // string and a valid email address
  email: refine(string(), 'email', (v) => isEmail.validate(v)),
  // password is between 7 and 30 characters long
  password: size(string(), 7, 30),
  // first name is between 2 and 50 characters long
  firstName: size(string(), 2, 50),
  // last name is between 2 and 50 characters long
  lastName: size(string(), 2, 50),
})

type Signup = Omit<Prisma.UserCreateArgs['data'], 'id'>

// Signup function
async function signup(input: Signup): Promise<User> {
  // Assert that input conforms to Signup, throwing with a helpful
  // error message if input is invalid.
  assert(input, Signup)
  return prisma.user.create({
    data: input.user,
  })
}

The example above shows how you can create a custom type-safe signup function that ensures the input is valid before creating a user.

Going further

• Learn how you can use Prisma Client extensions to add input validation for your queries — example.
• Learn how you can organize your code better by moving the signup function into a custom model.
• There's an outstanding feature request to bake user validation into Prisma Client. If you'd like to see that happen, make sure to upvote that issue and share your use case!