Practical Auth0: Login, APIs & Enterprise SSO

This course contains the use of artificial intelligence. Most Auth0 material stops at the moment the login button works. This one keeps going — through token validation, API authorization, the extensibility pipeline, B2B multi-tenancy, enterprise SSO, and the operational work that keeps an identity system alive once real customers depend on it.

You will follow one company the whole way. Halcyon Travel is a booking platform with two products: a consumer app used by travellers, and a corporate travel product sold to companies. They rolled their own authentication in year one — bcrypt, a users table, hand-signed tokens, a signing key nobody has dared rotate since 2021.

It creaks. Then a 4,000-seat enterprise prospect makes SAML single sign-on a contract condition, and the whole thing has to be rebuilt properly. Every concept in the course arrives because Halcyon hits a problem that needs it.

What the course coversFoundations — authentication vs authorization, where Auth0 sits in the identity landscape, tenants, application types, connections, and the two APIs you will live inOAuth 2. 0 and OIDC properly — the authorization code flow step by step, PKCE and why public clients need it, client credentials, refresh token rotation, the flows you should never use, and the discovery and JWKS documents that make it all self-describingUniversal Login in Next. js — wiring the Auth0 Next.

js SDK v4 with its middleware-mounted routes, sessions and rolling cookies, protecting server components and server actions, federated logout, and branding the login pageTokens — what ID, access and refresh tokens are actually for, the anatomy of a JWT, how to validate one correctly (signature, issuer, audience, expiry, algorithm), why your access token might be opaque, and the antipatterns that cause real breachesSecuring an API — registering a resource server, requesting and enforcing scopes, protecting Express routes, Auth0 RBAC, the difference between roles, scopes and permissions, and an honest look at where RBAC stops scalingActions — the extensibility model that replaces Rules and Hooks before their 18 November 2026 end of life: triggers, the event and api objects, namespaced custom claims, external calls and secrets, testing and deploymentB2B: Organizations and enterprise SSO — the multi-tenancy problem, organization login flows, invitations and just-in-time membership, org-scoped roles, SAML and OIDC enterprise connections to Okta and Entra ID, and a full enterprise onboarding runbookProduction hardening — MFA, step-up authentication for high-risk actions, passkeys and passwordless, attack protection, custom domains, and the classic session vulnerabilitiesOperations — logs and log streams, configuration as code with the Auth0 CLI and Terraform provider, dev to staging to production promotion, and migrating users off a legacy store without asking anyone to reset a passwordYou also get to do the work, not just watch it10 auto-graded coding exercises that run in your browser — build a PKCE challenge, validate an ID token, screen a batch of hostile tokens, write scope-checking middleware, author Action handlers. Each one fails you for the specific mistake the lecture warned about, not just for a wrong answer12 hands-on labs against your own free tenant, each with a self-check script that tells you what is wrong and where to look. You will trace an authorization code flow by hand, secure a real API, deploy an Action, stand up two organizations, and federate SAML between two tenants10 section quizzes and a 30-question final exam, scenario-based rather than recall-based — most describe something going wrong and ask you to identify whyA two-part capstone: Halcyon’s complete identity stack, consumer and enterprise, with a migration plan underneath bothHow it is taught.

Sixty lectures of motion-driven explanation — animated protocol flows, architecture diagrams that build as they are described, and token payloads dissected on screen. No background music. No wall of bullet points read aloud.

Everything runs free. The Auth0 Free plan covers the tenant, and the enterprise SSO material uses a second free tenant as the identity provider. No credit card is required at any point.

The course closes with a capstone brief: Halcyon’s complete identity stack, consumer and enterprise, plus the migration plan underneath both — specified as a business problem with three constraints rather than a list of steps to copy.