Adding custom headers to HTTP requests is essential for authentication, content type specification, and API communication in Angular applications. As the creator of CoreUI, a widely used open-source UI library, I’ve implemented custom headers in numerous Angular enterprise applications and admin dashboards. From my 25 years of experience in web development and 11 years with Angular, the most effective approach is to use the HttpHeaders class with HttpClient methods. This pattern provides type-safe header management and flexible request configuration.