This is a solid foundation for building permission systems. You get working implementations of RBAC with role inheritance in Node.js, ABAC with policy evaluation in Python, and pointers to Spring Security patterns for Java. The comparison table of different access control models (RBAC, ABAC, MAC, DAC, ReBAC) is genuinely helpful when you're deciding which approach fits your needs. The Express middleware example shows exactly how to gate routes with permission checks. What I appreciate is that it doesn't oversimplify. Real access control gets messy with role hierarchies and policy conflicts, and this at least acknowledges that complexity while giving you patterns that scale beyond toy examples.
npx skills add https://github.com/secondsky/claude-skills --skill access-control-rbac