alt-sendme is an accountless peer-to-peer file transfer tool designed for sending files and folders directly between devices. It operates as a decentralized sharing service that utilizes portable access tickets for identity exchange instead of centralized user accounts.
The project distinguishes itself through NAT and firewall traversal capabilities, using UDP hole punching and relay-based fallback routing to establish direct connections between remote devices. It supports multi-device data broadcasting, allowing a single file or folder to be shared with multiple recipients simultaneously through a coordinated session.
Data security is managed through end-to-end encryption and cryptographic hash verification to ensure file integrity. The system also supports resumable downloads via byte-offset tracking to continue interrupted transfers from the last successful packet.