Agent skill · security · secondsky
api-authentication
Secure API authentication with JWT, OAuth 2.0, API keys. Use for authentication systems, third-party integrations, service-to-service communication, or encountering token management, security headers, auth flow errors.
Why this skill is useful
Provides specific implementation details for JWT and OAuth 2.0 that the AI wouldn't reliably generate on its own.
What it needs
About 1k tokens when loaded. Last updated 2026-08-06. 204 stars on the source repository.
What this skill does
API Authentication Implement secure authentication mechanisms for APIs using modern standards and best practices. Authentication Methods Method Use Case Security Level -------- ---------- ---------------- JWT Stateless auth, SPAs High OAuth 2.0 Third-party integration High API Keys Service-to-service Medium Session Traditional web apps High JWT Implementation (Node.js) Security Requirements Always use HTTPS Store tokens in HttpOnly cookies (not localStorage) Hash passwords with bcrypt (cost factor 12+) Implement rate limiting on auth endpoints Rotate secrets regularly Never transmit tokens in URLs Security Headers Additional Implementations See references/python-flask.md for: Flask JWT with role-based access control decorators OAuth 2.0 Google integration with Authlib API key authentication with secure hashing Common Mistakes to Avoid Storing plain-text passwords Using weak JWT secrets Ignoring token expiration Disabling HTTPS in production Logging sensitive tokens
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills secondsky/api-authentication