Email validation
Arcjet allows you validate & verify an email address. This is useful for preventing users from signing up with fake email addresses and can significantly reduce the amount of spam or fraudulent accounts.
What is Arcjet?
Arcjet helps developers protect their apps in just a few lines of code. Bot detection. Rate limiting. Email validation. Attack protection. Data redaction. A developer-first approach to security.Quick start
This guide will show you how to add email validation and verification to
your
1. Install Arcjet
In your project root, run the following command to install the SDK:
bun add @arcjet/bunnpm i @arcjet/nestpnpm add @arcjet/nestyarn add @arcjet/nestnpm i @arcjet/nextpnpm add @arcjet/nextyarn add @arcjet/nextnpm i @arcjet/nodepnpm add @arcjet/nodeyarn add @arcjet/nodenpm i @arcjet/remixpnpm add @arcjet/remixyarn add @arcjet/remixnpm i @arcjet/sveltekitpnpm add @arcjet/sveltekityarn add @arcjet/sveltekit2. Set your key
Create a free Arcjet account then follow the
instructions to add a site and get a key. Add it to a .env.local file in your
project root.
ARCJET_KEY=ajkey_yourkeyARCJET_KEY=ajkey_yourkeyARCJET_KEY=ajkey_yourkeySince NODE_ENV for you, you also
need to set ARCJET_ENV in your environment file. This allows Arcjet to accept
a local IP address for development purposes.
# NODE_ENV is not set automatically, so tell Arcjet we're in dev# You can leave this unset in prodARCJET_ENV=development# Get your site key from https://app.arcjet.comARCJET_KEY=ajkey_yourkeySince NODE_ENV for you, you also
need to set ARCJET_ENV in your environment file. This allows Arcjet to accept
a local IP address for development purposes.
# NODE_ENV is not set automatically, so tell Arcjet we're in dev# You can leave this unset in prodARCJET_ENV=development# Get your site key from https://app.arcjet.comARCJET_KEY=ajkey_yourkeySince NODE_ENV for you, you also
need to set ARCJET_ENV in your environment file. This allows Arcjet to accept
a local IP address for development purposes.
# NODE_ENV is not set automatically, so tell Arcjet we're in dev# You can leave this unset in prodARCJET_ENV=development# Get your site key from https://app.arcjet.comARCJET_KEY=ajkey_yourkey3. Validate an email address
The example below shows how to use Arcjet to check an email address. If the email address is invalid or if no MX records are configured, Arcjet will return a deny decision.
import arcjet, { validateEmail } from "@arcjet/bun";import { env } from "bun";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ validateEmail({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // block disposable, invalid, and email addresses with no MX records block: ["DISPOSABLE", "INVALID", "NO_MX_RECORDS"], }), ],});
export default { port: 3000, fetch: aj.handler(async (req) => { const decision = await aj.protect(req, { // The email prop is required when a validateEmail rule is configured. // TypeScript will guide you based on the configured rules email: "test@0zc7eznv3rsiswlohu.tk", });
if (decision.isDenied()) { return new Response("Forbidden", { status: 403 }); }
return new Response("Hello world"); }),};import arcjet, { validateEmail } from "@arcjet/bun";import { env } from "bun";
const aj = arcjet({ key: env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ validateEmail({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // block disposable, invalid, and email addresses with no MX records block: ["DISPOSABLE", "INVALID", "NO_MX_RECORDS"], }), ],});
export default { port: 3000, fetch: aj.handler(async (req) => { const decision = await aj.protect(req, { // The email prop is required when a validateEmail rule is configured. email: "test@0zc7eznv3rsiswlohu.tk", });
if (decision.isDenied()) { return new Response("Forbidden", { status: 403 }); }
return new Response("Hello world"); }),};If you are using server actions, see the example in the SDK reference.
Create a new API route at /app/api/arcjet/route.ts:
import arcjet, { validateEmail } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ validateEmail({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // block disposable, invalid, and email addresses with no MX records block: ["DISPOSABLE", "INVALID", "NO_MX_RECORDS"], }), ],});
export async function POST(req: Request) { const decision = await aj.protect(req, { // The email prop is required when a validateEmail rule is configured. // TypeScript will guide you based on the configured rules email: "test@0zc7eznv3rsiswlohu.tk", });
if (decision.isDenied()) { return NextResponse.json({ error: "Forbidden" }, { status: 403 }); }
return NextResponse.json({ message: "Hello world", });}Create a new API route at /app/api/arcjet/route.js:
import arcjet, { validateEmail } from "@arcjet/next";import { NextResponse } from "next/server";
const aj = arcjet({ key: process.env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ validateEmail({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // block disposable, invalid, and email addresses with no MX records block: ["DISPOSABLE", "INVALID", "NO_MX_RECORDS"], }), ],});
export async function POST(req) { const decision = await aj.protect(req, { // The email prop is required when a validateEmail rule is configured. email: "test@0zc7eznv3rsiswlohu.tk", });
if (decision.isDenied()) { return NextResponse.json({ error: "Forbidden" }, { status: 403 }); }
return NextResponse.json({ message: "Hello world", });}Create a new API route at /pages/api/arcjet.js:
import arcjet, { validateEmail } from "@arcjet/next";
const aj = arcjet({ key: process.env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ validateEmail({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // block disposable, invalid, and email addresses with no MX records block: ["DISPOSABLE", "INVALID", "NO_MX_RECORDS"], }), ],});
export default async function handler(req, res) { const decision = await aj.protect(req, { // The email prop is required when a validateEmail rule is configured. email: "test@0zc7eznv3rsiswlohu.tk", });
if (decision.isDenied()) { return res .status(403) .json({ error: "Forbidden", reason: decision.reason }); }
res.status(200).json({ name: "Hello world" });}Create a new API route at /pages/api/arcjet.ts:
import arcjet, { validateEmail } from "@arcjet/next";import type { NextApiRequest, NextApiResponse } from "next";
const aj = arcjet({ key: process.env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ validateEmail({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // block disposable, invalid, and email addresses with no MX records block: ["DISPOSABLE", "INVALID", "NO_MX_RECORDS"], }), ],});
export default async function handler( req: NextApiRequest, res: NextApiResponse,) { const decision = await aj.protect(req, { // The email prop is required when a validateEmail rule is configured. // TypeScript will guide you based on the configured rules email: "test@0zc7eznv3rsiswlohu.tk", });
if (decision.isDenied()) { return res .status(403) .json({ error: "Forbidden", reason: decision.reason }); }
res.status(200).json({ name: "Hello world" });}Create a new API route at /src/routes/api/arcjet/+server.ts:
import { env } from "$env/dynamic/private";import arcjet, { validateEmail } from "@arcjet/sveltekit";import { error, json, type RequestEvent } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY!, // Get your site key from https://app.arcjet.com rules: [ validateEmail({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // block disposable, invalid, and email addresses with no MX records block: ["DISPOSABLE", "INVALID", "NO_MX_RECORDS"], }), ],});
export async function POST(event: RequestEvent) { const decision = await aj.protect(event, { // The email prop is required when a validateEmail rule is configured. // TypeScript will guide you based on the configured rules email: "test@0zc7eznv3rsiswlohu.tk", });
if (decision.isDenied()) { return error(403, "Forbidden"); }
return json({ message: "Hello world" });}Create a new API route at /src/routes/api/arcjet/+server.js:
import { env } from "$env/dynamic/private";import arcjet, { validateEmail } from "@arcjet/sveltekit";import { error, json } from "@sveltejs/kit";
const aj = arcjet({ key: env.ARCJET_KEY, // Get your site key from https://app.arcjet.com rules: [ validateEmail({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // block disposable, invalid, and email addresses with no MX records block: ["DISPOSABLE", "INVALID", "NO_MX_RECORDS"], }), ],});
export async function POST(event) { const decision = await aj.protect(event, { // The email prop is required when a validateEmail rule is configured. email: "test@0zc7eznv3rsiswlohu.tk", });
if (decision.isDenied()) { return error(403, "Forbidden"); }
return json({ message: "Hello world" });}Create a new route at app/routes/arcjet.tsx with the contents:
import arcjet, { validateEmail } from "@arcjet/remix";import type { ActionFunctionArgs } from "@remix-run/node";
const aj = arcjet({ // Get your site key from https://app.arcjet.com and set it as an environment // variable rather than hard coding. key: process.env.ARCJET_KEY!, rules: [ validateEmail({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // block disposable, invalid, and email addresses with no MX records block: ["DISPOSABLE", "INVALID", "NO_MX_RECORDS"], }), ],});
// The action function is called for non-GET requests, which is where you// typically handle form submissions that might contain an email address.export async function action(args: ActionFunctionArgs) { // The request body is a FormData object const formData = await args.request.formData(); const email = formData.get("email") as string;
const decision = await aj.protect(args, { email }); console.log("Arcjet decision", decision);
if (decision.isDenied()) { if (decision.reason.isEmail()) { return Response.json({ error: "Invalid email." }, { status: 400 }); } else { return Response.json({ error: "Forbidden" }, { status: 403 }); } }
// We don't need to use the decision elsewhere, but you could return it to // the component return null;}import arcjet, { validateEmail } from "@arcjet/remix";
const aj = arcjet({ // Get your site key from https://app.arcjet.com and set it as an environment // variable rather than hard coding. key: process.env.ARCJET_KEY, rules: [ validateEmail({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // block disposable, invalid, and email addresses with no MX records block: ["DISPOSABLE", "INVALID", "NO_MX_RECORDS"], }), ],});
// The action function is called for non-GET requests, which is where you// typically handle form submissions that might contain an email address.export async function action(args) { // The request body is a FormData object const formData = await args.request.formData(); const email = formData.get("email");
const decision = await aj.protect(args, { email }); console.log("Arcjet decision", decision);
if (decision.isDenied()) { if (decision.reason.isEmail()) { return Response.json({ error: "Invalid email." }, { status: 400 }); } else { return Response.json({ error: "Forbidden" }, { status: 403 }); } }
// We don't need to use the decision elsewhere, but you could return it to // the component return null;}import arcjet, { validateEmail } from "@arcjet/node";import express from "express";
const app = express();const port = 3000;
app.use(express.urlencoded({ extended: false }));
const aj = arcjet({ // Get your site key from https://app.arcjet.com and set it as an environment // variable rather than hard coding. key: process.env.ARCJET_KEY!, rules: [ validateEmail({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // block disposable, invalid, and email addresses with no MX records block: ["DISPOSABLE", "INVALID", "NO_MX_RECORDS"], }), ],});
app.post("/", async (req, res) => { console.log("Email received: ", req.body.email);
const decision = await aj.protect(req, { email: req.body.email, }); console.log("Arcjet decision", decision);
if (decision.isDenied()) { res.writeHead(403, { "Content-Type": "application/json" }); res.end(JSON.stringify({ error: "Forbidden" })); } else { res.writeHead(200, { "Content-Type": "application/json" }); res.end(JSON.stringify({ message: "Hello World", email: req.body.email })); }});
app.listen(port, () => { console.log(`Example app listening on port ${port}`);});import arcjet, { validateEmail } from "@arcjet/node";import express from "express";
const app = express();const port = 3000;
app.use(express.urlencoded({ extended: false }));
const aj = arcjet({ // Get your site key from https://app.arcjet.com and set it as an environment // variable rather than hard coding. key: process.env.ARCJET_KEY, rules: [ validateEmail({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // block disposable, invalid, and email addresses with no MX records block: ["DISPOSABLE", "INVALID", "NO_MX_RECORDS"], }), ],});
app.post("/", async (req, res) => { console.log("Email received: ", req.body.email);
const decision = await aj.protect(req, { email: req.body.email, }); console.log("Arcjet decision", decision);
if (decision.isDenied()) { res.writeHead(403, { "Content-Type": "application/json" }); res.end(JSON.stringify({ error: "Forbidden" })); } else { res.writeHead(200, { "Content-Type": "application/json" }); res.end(JSON.stringify({ message: "Hello World", email: req.body.email })); }});
app.listen(port, () => { console.log(`Example app listening on port ${port}`);});Several files are combined here to demonstrate creating a form handler controller. In a real application you should split them as suggested in the comments.
import { ArcjetGuard, ArcjetModule } from "@arcjet/nest";import { Module } from "@nestjs/common";import { ConfigModule } from "@nestjs/config";import { APP_GUARD, NestFactory } from "@nestjs/core";
@Module({ imports: [ ConfigModule.forRoot({ isGlobal: true, }), ArcjetModule.forRoot({ isGlobal: true, key: process.env.ARCJET_KEY!, rules: [ // We're not adding any rules here for this example, but if you did they // would be the default rules wherever you use Arcjet. ], }), ], controllers: [], providers: [ { provide: APP_GUARD, useClass: ArcjetGuard, }, ],})class AppModule {}
async function bootstrap() { const app = await NestFactory.create(AppModule); await app.listen(3000);}bootstrap();import { ARCJET, type ArcjetNest, validateEmail } from "@arcjet/nest";import { Body, Controller, HttpException, HttpStatus, Inject, Injectable, Logger, Post, Req, UseInterceptors,} from "@nestjs/common";import { NoFilesInterceptor } from "@nestjs/platform-express";import { IsNotEmpty } from "class-validator";import type { Request } from "express";
// Validation class as described at// https://docs.nestjs.com/techniques/validation. We're not using the IsEmail// decorator here because Arcjet handles this for you.export class SignupDto { @IsNotEmpty() // @ts-ignore: This is a DTO class so ignore that it's not definitely assigned email: string;}
// This would normally go in your service file e.g.// src/signup/signup.service.ts@Injectable()export class SignupService { private readonly logger = new Logger(SignupService.name);
signup(email: string): { message: string } { this.logger.log(`Form submission: ${email}`);
return { message: "Hello world", }; }}
// This would normally go in your controller file e.g.// src/signup/signup.controller.ts@Controller("signup")export class SignupController { private readonly logger = new Logger(SignupController.name);
constructor( private readonly signupService: SignupService, @Inject(ARCJET) private readonly arcjet: ArcjetNest, ) {}
// Implement a form handler following // https://docs.nestjs.com/techniques/file-upload#no-files. Note this isn't // compatible with the NestJS Fastify adapter. @Post() @UseInterceptors(NoFilesInterceptor()) async index(@Req() req: Request, @Body() body: SignupDto) { const decision = await this.arcjet .withRule( validateEmail({ mode: "LIVE", // will block requests. Use "DRY_RUN" to log only // block disposable, invalid, and email addresses with no MX records block: ["DISPOSABLE", "INVALID", "NO_MX_RECORDS"], }), ) .protect(req, { email: body.email });
this.logger.log(`Arcjet: id = ${decision.id}`); this.logger.log(`Arcjet: decision = ${decision.conclusion}`);
if (decision.isDenied()) { if (decision.reason.isEmail()) { this.logger.log(`Arcjet: email error = ${decision.reason.emailTypes}`);
let message: string;
// These are specific errors to help the user, but will also reveal the // validation to a spammer. if (decision.reason.emailTypes.includes("INVALID")) { message = "email address format is invalid. Is there a typo?"; } else if (decision.reason.emailTypes.includes("DISPOSABLE")) { message = "we do not allow disposable email addresses."; } else if (decision.reason.emailTypes.includes("NO_MX_RECORDS")) { message = "your email domain does not have an MX record. Is there a typo?"; } else { // This is a catch all, but the above should be exhaustive based on the // configured rules. message = "invalid email."; }
throw new HttpException(`Error: ${message}`, HttpStatus.BAD_REQUEST); } else { throw new HttpException("Forbidden", HttpStatus.FORBIDDEN); } }
return this.signupService.signup(body.email); }}4. Start app
Start your app and load http://localhost:5173/api/arcjet. The email address is
from a disposable email service, so the decision is to deny. This can be adapted
to API routes in your application which accept user submissions e.g. a signup
form.
4. Start server
bun run --hot index.tsbun run --hot index.jsLoad http://localhost:3000/api/arcjet. The email address is from a disposable
email service, so the decision is to deny. This can be adapted to API routes in
your application which accept user submissions e.g. a signup form.
4. Start app
npm run startpnpm run startyarn run startMake a curl POST request from your terminal to your application with various
emails to test the result.
curl -X POST -d 'email=test@arcjet.io' http://localhost:3000/signup/4. Start app
Start your Next.js app:
npm run devpnpm run devyarn run devThen load http://localhost:3000/api/arcjet. The email address is from a
disposable email service, so the decision is to deny. This can be adapted to API
routes in your application which accept user submissions e.g. a signup form.
4. Start server
npx tsx --env-file .env.local index.tsnode --env-file .env.local index.jsMake a curl POST request from your terminal to your application with various
emails to test the result.
curl -X POST -d 'email=test@arcjet.io' http://localhost:3000/4. Start app
npm run devpnpm run devyarn run devMake a curl POST request from your terminal to your application with various
emails to test the result.
curl -X POST -d 'email=test@arcjet.io' http://localhost:5173/arcjet.data?indexThe requests will also show in the Arcjet dashboard.
FAQs
Do I need to run any infrastructure e.g. Redis?
No, Arcjet handles all the infrastructure for you so you don't need to worry about deploying global Redis clusters, designing data structures to track rate limits, or keeping security detection rules up to date.
What is the performance overhead?
Arcjet SDK tries to do as much as possible asynchronously and locally to minimize latency for each request. Where decisions can be made locally or previous decisions are cached in-memory, latency is usually <1ms.
When a call to the Arcjet API is required, such as when tracking a rate limit in a serverless environment, there is some additional latency before a decision is made. The Arcjet API has been designed for high performance and low latency, and is deployed to multiple regions around the world. The SDK will automatically use the closest region which means the total overhead is typically no more than 20-30ms, often significantly less.
What happens if Arcjet is unavailable?
Where a decision has been cached locally e.g. blocking a client, Arcjet will continue to function even if the service is unavailable.
If a call to the Arcjet API is needed and there is a network problem or Arcjet is unavailable, the default behavior is to fail open and allow the request. You have control over how to handle errors, including choosing to fail close if you prefer. See the reference docs for details.
How does Arcjet protect me against DDoS attacks?
Network layer attacks tend to be generic and high volume, so these are best handled by your hosting platform. Most cloud providers include network DDoS protection by default.
Arcjet sits closer to your application so it can understand the context. This is important because some types of traffic may not look like a DDoS attack, but can still have the same effect. For example, a customer making too many API requests and affecting other customers, or large numbers of signups from disposable email addresses.
Network-level DDoS protection tools find it difficult to protect against this type of traffic because they don't understand the structure of your application. Arcjet can help you to identify and block this traffic by integrating with your codebase and understanding the context of the request e.g. the customer ID or sensitivity of the API route.
Volumetric network attacks are best handled by your hosting provider. Application level attacks need to be handled by the application. That's where Arcjet helps.
What next?
Arcjet can be used with specific rules on individual routes or as general protection on your entire application. You can customize bot protection, rate limiting for your API and minimize fraudulent registrations with the signup form protection.
Get help
Need help with anything? Email support@arcjet.com to get support from our engineering team.