Complete technical guide to CeFinan's passwordless authentication process
๐ Published on November 17, 2025
A Magic Link is a unique, temporary link sent via email that allows users to log into an application without a password. It's like receiving a temporary digital key directly in your mailbox.
Simple Formula: Email + Unique Token + Temporary Access = Magic Link
No password to remember
Each link is unique and expires automatically
No more "forgot password" issues
Proves the user controls the email address
The user arrives at the login page and enters only their email. The system automatically checks whether it's a new user or an existing user.
// User verification
const { exists } = await fetch('/api/auth/check-user', {
body: JSON.stringify({ email })
})The system generates a unique and secure token:
const token = crypto.randomBytes(32).toString('hex')
const expires = new Date()
expires.setHours(expires.getHours() + 24) // Expires in 24hhttps://yoursite.com/auth/verify?email=user@example.com&token=abc123...A professional email is sent with:
When the user clicks the link:
// Server-side verification
const isValid = await verifyToken(email, token)
if (isValid) {
createUserSession()
redirectToApp()
}Impossible to guess
24 hours maximum
Each token works only once
Total time: ~30 seconds (depending on email delivery speed)
Maximum security
Simplicity for professionals
Optimized UX
Newsletters, reports, etc.
Reduced signup friction
The Magic Link represents the natural evolution of web authentication: simple, secure, and user-centered. It's the perfect solution for modern applications that prioritize simplicity without compromising security. ๐โจ