Taildrop was kind of easy, actually

Taildrop, a feature launched in Tailscale v1.8, allows users to transfer files between their devices directly over a point-to-point Tailscale+WireGuard mesh network, bypassing cloud storage and maintaining end-to-end encryption. This service functions across different operating systems and doesn't require Bluetooth, offering a seamless and secure file-sharing experience. While the implementation of Taildrop is simpler than traditional methods like FTP, it benefits from Tailscale's authenticated and encrypted network, eliminating the need for complex server infrastructure or cloud services. The development process incorporated new capabilities such as the "localapi" for querying devices and "peerapi" for inter-device communication, showcasing Tailscale's potential to simplify file transfers without incurring hosting costs or compromising privacy. Despite the apparent simplicity, the development aimed to create a robust, open-source solution that could be freely used without size limitations, highlighting a shift towards more user-friendly and secure internet protocols.