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FastAPI Auth series cover — layered security shields with lock icons representing authentication and authorization patterns
Series in progress

FastAPI Auth: From Passwords to SSO

Eight-part deep dive into authentication and authorization in FastAPI — from password hashing through JWT, OAuth 2.0, OpenID Connect, and SSO, with flow diagrams, working code, and a decision framework for choosing the right approach.

8 parts 1h 19m total
Begin with Part 1

In this series

  1. 1 The Security Mental Model You Need First 9 min read

    Authentication and authorization are two different problems that most tutorials conflate. Here is the mental model, threat landscape, and FastAPI security toolkit you need before writing a single line of auth code.

  2. 2 Password Authentication Done Right 12 min read

    Password hashing is not security — it is one layer. Here is how to build registration, login, session management, and brute-force protection in FastAPI without the mistakes that lead to credential breaches.

  3. 3 JWT Tokens — Stateless Authentication 10 min read

    JWTs eliminate session storage but introduce revocation challenges. Here is how to build access tokens, refresh tokens, and token rotation in FastAPI — with the security pitfalls that tutorials never mention.

  4. 4 API Key Authentication for Machine Clients 9 min read

    API keys are the most misused auth mechanism in production. Here is how to generate, scope, rotate, and rate-limit API keys in FastAPI — with the patterns that separate toy projects from production systems.

  5. 5 OAuth 2.0 — The Authorization Framework 9 min read

    OAuth 2.0 is not authentication — it is authorization. Here are the four grant types, why PKCE is now mandatory, and how to implement the authorization code flow in FastAPI with working code and sequence diagrams.

  6. 6 OpenID Connect and Single Sign-On 9 min read

    OAuth 2.0 does not tell you who the user is. OpenID Connect adds the identity layer. Here is how to implement Google SSO, validate ID tokens, and understand when OIDC beats SAML.

  7. 7 Authorization Patterns — RBAC, ABAC, and Beyond 10 min read

    Authentication answers who. Authorization answers what. Here are three authorization models — RBAC, ABAC, and ReBAC — implemented as FastAPI dependencies with decision flows, comparison tables, and production patterns.

  8. 8 The Decision Framework — Choosing the Right Approach 11 min read

    Eight authentication and authorization methods, one decision tree. Here is the comparison matrix, production combination patterns, and pre-launch security checklist that turns auth knowledge into shipping decisions.