Practical Auth0 Login, APIs & Enterprise SSO

Universal Login, OAuth 2.0, token validation, Actions, Organizations and SAML SSO on a free tenant.
What you'll learn

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Implement Universal Login in a Next.js 15 app with correct session, cookie and logout handling
Trace an OAuth 2.0 / OIDC flow end to end and choose the right grant for any client type
Validate a JWT correctly - signature, issuer, audience, expiry, algorithm - and spot the antipatterns
Secure an API with audiences, scopes and Auth0 RBAC, and explain where RBAC stops scaling
Extend the login pipeline with Actions: namespaced claims, external calls, deny rules, step-up
Deliver B2B multi-tenancy with Organizations, org-scoped roles and enterprise SAML SSO
Harden a tenant with MFA, step-up authentication, passkeys and attack protection
Operate identity in production: log streams, Terraform config-as-code, tenant promotion, user migration
Recognise why Rules and Hooks are ending, and write Actions instead
Migrate users off a legacy password store without forcing a single password reset
Requirements

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Comfortable building a basic web application and a REST API in JavaScript
Working knowledge of Node.js and npm
Familiarity with HTTP - requests, responses, headers, cookies, redirects
A free Auth0 account (no credit card required - the sign-up is covered in the course)
No prior identity, OAuth or security experience is assumed
Description

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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 covers
Foundations - authentication vs authorization, where Auth0 sits in the identity landscape, tenants, application types, connections, and the two APIs you will live in
OAuth 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-describing
Universal 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 page
Tokens - 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 breaches
Securing 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 scaling
Actions - the extensibility model that replaces Rules and Hooks before their18 November 2026 end of life: triggers, the event and api objects, namespaced custom claims, external calls and secrets, testing and deployment
B2B: 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 runbook
Production hardening - MFA, step-up authentication for high-risk actions, passkeys and passwordless, attack protection, custom domains, and the classic session vulnerabilities
Operations - 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 password
You also get to do the work, not just watch it
10 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 answer
12 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 tenants
10 section quizzes and a 30-question final exam, scenario-based rather than recall-based - most describe something going wrong and ask you to identify why
A two-part capstone: Halcyon's complete identity stack, consumer and enterprise, with a migration plan underneath both
How 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.
Who this course is for

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Full-stack and backend developers who have been handed a ticket that says "add login"
Platform and security engineers who own an identity system and want to understand it properly
Developers whose product just sold to an enterprise customer demanding SAML SSO
Anyone maintaining Auth0 Rules or Hooks who needs to move to Actions before the 2026 EOL
Engineers who can wire up a login form but could not explain what the audience claim is for
Homepage

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