Introduction

Authfy is an authentication platform for your applications. Instead of every app building and maintaining its own login screens, password rules, user database, and security emails, your apps plug into Authfy and get all of it as a service.

What you get

• Single sign-on (SSO). Your users sign in once and move between all of your connected applications without logging in again. Authfy implements the industry-standard OAuth 2.0 / OpenID Connect Authorization Code + PKCE flow.
• One user directory. Users, their profiles, and their credentials live in one place. An email address identifies the same person across every app.
• Company workspaces. Users belong to companies (organizations), and companies subscribe to applications. Access can be scoped further with categories — for example, only the Finance team sees the finance app.
• Security handled for you. Short-lived signed tokens, per-application signing keys, validated redirect URLs, brute-force lockouts, password policy, and a full audit trail — maintained by the platform, not by each app.
• Account lifecycle emails. Welcome and password-setup emails, password reset, and security notices are sent automatically, branded for your company.
• Email & SMS for your app. Beyond authentication, your applications can send their own transactional email and SMS through Authfy's notification API, under your company's identity and branding.

How you'll use it

1. Your Authfy administrator registers your application and gives you three things: an App ID, the application public key, and the Authfy URLs for your environment.
2. You install the authfy npm package (for Next.js apps this is a two-file setup) — sign-in, sign-out, sessions, and token refresh all work at that point.
3. When your app needs data — the signed-in company, its users, its categories — you call the External API.
4. If your app sends notifications, you use the email & SMS API with your company's API key.

Where to go next

• Architecture — how the pieces fit together, explained simply.
• The authfy npm package — install and set up SSO in your app.
• External API — every endpoint, with sample requests and responses.
• Sending email & SMS — the notification API.