NestJS Guards

When to Use This Skill

Use this skill when:

• Implementing authentication (verifying user identity)
• Implementing authorization (checking user permissions/roles)
• Protecting routes based on user roles or permissions
• Validating JWT tokens or API keys
• Implementing custom access control logic
• Restricting access based on request context
• Building role-based access control (RBAC) systems
• Implementing feature flags or conditional route access

What are Guards?

Guards determine whether a request will be handled by the route handler. They implement the CanActivate interface and return a boolean value (or Promise/Observable) indicating whether access is allowed.

Guards execute after middleware but before interceptors and pipes in the request lifecycle.