Authentication

Stop building auth.
Start shipping product.

Every way to sign in -- email, social, magic links, OTP, MFA, passkeys -- from one SDK call. Branded login page included. Free for 5,000 users.

Available on Free and above. See pricing

Branded login, out of the box

Your users see your brand. Every login page is fully customizable.

auth.acme.com/login
Logo

Welcome to Acme

Sign in to continue

Email
alice@acme.com
Password
............
or continue with

Six auth methods. One API.

Every method works out of the box. Toggle them on from the dashboard.

Email / Password

Breach detection, progressive lockout, configurable policy.

Social Login

Google, GitHub, GitLab. One click. Profile synced.

Magic Links

Passwordless email login. 15-min single-use tokens.

OTP (Email)

6-digit code, 5-min expiry, 5 attempts max.

MFA (TOTP)

Google Authenticator, Authy. QR enrollment. 10 backup codes.

Passkeys

WebAuthn / FIDO2. Biometric. Phishing-resistant.

Three lines of code. Seven languages.

Install the SDK. Initialize. Protect routes. That's it.

const auth = authfi({ tenant: 'acme' });
app.use(auth.middleware());
app.get('/api/users', auth.require('read:users'), handler);

Security built in. Not bolted on.

Breached password detection

700M+ compromised passwords checked on every signup and login.

PKCE + token rotation

S256 PKCE on every flow. Automatic refresh token rotation with family detection.

Per-tenant RSA keys

Every tenant gets unique RSA-256 signing keys. No shared secrets.

Ready to get started?

Free for 5,000 monthly active users. No credit card required.