Building API Authentication Overview Build secure API authentication systems supporting JWT Bearer tokens, OAuth 2.0 authorization code and client credentials flows, API key management, and session-based authentication. Implement token issuance, validation, refresh rotation, revocation, and role-based access control (RBAC) with scoped permissions across all API endpoints. Prerequisites - Cryptographic library: (Node.js), (Python), or (Java) - Secure secret storage: environment variables, AWS Secrets Manager, or HashiCorp Vault for JWT signing keys - Database table for user credentials, refres…