---
title: User signup flow
description: Handle user registration with automated welcome emails and email verification using secure tokens.
image: https://developers.cloudflare.com/dev-products-preview.png
---

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# User signup flow

Send welcome and verification emails during user signup with secure token-based email verification.

This example demonstrates a complete user registration system with welcome emails and email verification.

TypeScript

```

interface Env {

  EMAIL: SendEmail;

  USERS: KVNamespace;

  VERIFICATION_TOKENS: KVNamespace;

  DOMAIN: string;

  COMPANY_NAME: string;

}


interface User {

  id: string;

  email: string;

  firstName: string;

  verified: boolean;

  createdAt: string;

}


export default {

  async fetch(request: Request, env: Env): Promise<Response> {

    const url = new URL(request.url);


    if (url.pathname === "/signup" && request.method === "POST") {

      return handleSignup(request, env);

    }


    if (url.pathname === "/verify" && request.method === "GET") {

      return handleVerification(request, env);

    }


    return new Response("Not Found", { status: 404 });

  },

};


async function handleSignup(request: Request, env: Env): Promise<Response> {

  const { email, firstName } = await request.json();


  // Validate and check for existing user

  if (!email || !firstName || !isValidEmail(email)) {

    return new Response(JSON.stringify({ error: "Invalid input" }), {

      status: 400,

    });

  }


  if (await env.USERS.get(email)) {

    return new Response(JSON.stringify({ error: "User already exists" }), {

      status: 409,

    });

  }


  // Create user

  const userId = crypto.randomUUID();

  const user: User = {

    id: userId,

    email,

    firstName,

    verified: false,

    createdAt: new Date().toISOString(),

  };


  await env.USERS.put(email, JSON.stringify(user));


  // Generate verification token (expires in 1 hour)

  const verificationToken = crypto.randomUUID();

  await env.VERIFICATION_TOKENS.put(verificationToken, email, {

    expirationTtl: 3600,

  });


  // Send welcome email

  await env.EMAIL.send({

    to: email,

    from: `noreply@${env.DOMAIN}`,

    subject: `Welcome to ${env.COMPANY_NAME}!`,

    html: `

      <h1>Welcome ${firstName}!</h1>

      <p>Thanks for joining ${env.COMPANY_NAME}. Please verify your email to get started.</p>

    `,

  });


  // Send verification email

  const verificationUrl = `https://${env.DOMAIN}/verify?token=${verificationToken}`;

  await env.EMAIL.send({

    to: email,

    from: `noreply@${env.DOMAIN}`,

    subject: "Please verify your email address",

    html: `

      <h1>Verify Your Email</h1>

      <p>Hi ${firstName}! Click the link below to verify your email:</p>

      <a href="https://developers.cloudflare.com/email-service/examples/email-sending/signup-flow/%3C/span%3E%3Cspan%20style="--0:#89DDFF;--1:#007474">${verificationUrl}" style="background: #007bff; color: white; padding: 12px 24px; text-decoration: none; border-radius: 4px;">Verify Email</a>

      <p>This link expires in 1 hour.</p>

    `,

  });


  return new Response(

    JSON.stringify({

      success: true,

      message: "Account created. Please check your email.",

      userId,

    }),

    { status: 201 },

  );

}


async function handleVerification(

  request: Request,

  env: Env,

): Promise<Response> {

  const url = new URL(request.url);

  const token = url.searchParams.get("token");


  if (!token) {

    return new Response("Missing token", { status: 400 });

  }


  // Verify token

  const userEmail = await env.VERIFICATION_TOKENS.get(token);

  if (!userEmail) {

    return new Response("Invalid or expired token", { status: 400 });

  }


  // Get and update user

  const userData = await env.USERS.get(userEmail);

  if (!userData) {

    return new Response("User not found", { status: 404 });

  }


  const user: User = JSON.parse(userData);

  user.verified = true;


  await env.USERS.put(user.email, JSON.stringify(user));

  await env.VERIFICATION_TOKENS.delete(token);


  return new Response(

    `

    <html>

      <body style="font-family: Arial, sans-serif; text-align: center; padding: 50px;">

        <h1>✅ Email Verified!</h1>

        <p>Welcome ${user.firstName}! Your account is now active.</p>

        <a href="https://developers.cloudflare.com/" style="background: #28a745; color: white; padding: 12px 24px; text-decoration: none; border-radius: 4px;">Continue</a>

      </body>

    </html>

  `,

    {

      headers: { "Content-Type": "text/html" },

    },

  );

}


function isValidEmail(email: string): boolean {

  return /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email);

}


```

Explain Code

```json
{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/directory/","name":"Directory"}},{"@type":"ListItem","position":2,"item":{"@id":"/email-service/","name":"Email Service"}},{"@type":"ListItem","position":3,"item":{"@id":"/email-service/examples/","name":"Examples"}},{"@type":"ListItem","position":4,"item":{"@id":"/email-service/examples/email-sending/","name":"Email sending"}},{"@type":"ListItem","position":5,"item":{"@id":"/email-service/examples/email-sending/signup-flow/","name":"User signup flow"}}]}
```