More widespread implementation of inter-domain route management in today’s Internet could lead to improved network speed, reliability, and utility for both end users and Internet service providers (ISPs). Although many source routing techniques have been proposed by researchers to address this limitation, autonomous systems that can govern themselves still lack the ability to detect when traffic is trying to bypass local policies or to charge the right party for forwarding it. We introduce Platypus, a network capability-based authenticated source routing system that enables accountable optimum path selection through cryptographic proof of policy compliance at each source route hop. Third parties can be entrusted with the ability to compose routes through numerous autonomous systems. Users benefit from resource pooling and the option to choose alternate routes using Platypus, while Internet service providers (ISPs) keep control over the timing, location, and identity of packets passing via their networks. By decoupling the problems of connection discovery and path selection, we can lessen this complexity. A chance arises for edge networks and end users when policy limitations are removed from route detection. Autonomous systems can now reveal routes that were earlier hidden by overly traditional procedure filters, allowing packets to transit them.