What is Atlas?

Atlas is a complete, self-hostable authentication and user-management platform — the kind of drop-in auth you'd reach for Clerk or Auth0 to provide, but one you can also run on your own infrastructure.

You point your app at Atlas and get sign-up and sign-in flows, sessions, multi-factor auth and passkeys, organizations and B2B multi-tenancy, roles and permissions, enterprise SSO (SAML), SCIM provisioning, and webhooks — reachable from a hosted UI, a large SDK lineup, and a REST API.

What you get

• Authentication — password, email codes, magic links, passkeys/WebAuthn, and 100+ social providers (Google, GitHub, Microsoft, Apple, and more).

• Sessions — issued as standard JWTs, verifiable statelessly against your instance's JWKS.

• Organizations & B2B — multi-tenant organizations with memberships, invitations, and per-org roles.

• Authorization — organization roles & permissions (RBAC) plus fine-grained, relationship-based access (FGA, OpenFGA-compatible).

• Enterprise — SSO via SAML, and SCIM directory provisioning.

• MFA — TOTP authenticator apps, SMS, backup codes, and passkeys.

• Webhooks — subscribe to user, session, and organization events.

How it fits together

Atlas exposes two API surfaces, each with its own key:

• The Frontend API (FAPI) runs sign-in/sign-up flows from the browser or a mobile app. It is called with a publishable key (pk_...), which is safe to ship in client code.

• The Backend API (BAPI) is the full management surface — users, organizations, roles, SSO, SCIM, webhooks, billing. It is called from your server with a secret key (sk_...), which must never leave your backend.

Your frontend runs the flow with the publishable key; your backend either verifies the resulting session JWT locally (no round trip) or calls the Backend API with the secret key.

SDKs

Atlas ships official SDKs across the stack:

• Frontend — @atlas/js, @atlas/react, @atlas/nextjs, @atlas/vue, @atlas/nuxt, @atlas/angular, @atlas/svelte, @atlas/react-native.

• Backend — @atlas/backend (Node), plus Python, Go, Ruby, PHP, Java, and .NET.

• Native mobile — Swift (iOS/macOS), Kotlin (Android), and Flutter.

See the SDK overview for a snippet of each.

Next steps

• Create an application and get your keys.

• Protect a route with the React or Next.js SDK.

• Authorize your users with roles, permissions, and FGA.

• Self-host Atlas on your own infrastructure.

Need a hand? Email support@atlasauth.net.