Osewa – An open-source alternative to SSH and Mosh

Osewa is an open-source terminal connection tool designed for long-running work on remote machines, especially when users need to reconnect from changing or unreliable networks. It aims to combine SSH’s secure access with Mosh’s roaming support while avoiding Mosh’s display-fidelity limitations. Unlike SSH, which ties a session to a single TCP connection, Osewa keeps the terminal session running on the host, so connections can drop and resume without losing the process, screen, or unacknowledged keystrokes. It uses TLS 1.3 and Ed25519 keys, and races QUIC against a TLS-protected WebSocket connection so it can fall back when UDP is blocked. Keystrokes take priority over bulk transfers, and the system favors the latest screen state over replaying a stale backlog.

The displayed benchmarks report substantially faster key echo than SSH under packet loss and bandwidth contention: eight to twelve times faster in two tests, and more than 100 times faster in a constrained 1 Mbit/s test where SSH produced no echo within 15 seconds. A Thailand-to-Tokyo connection test also shows lower command-start latency than SSH or Mosh. Osewa uses less idle host memory than either comparison, and less idle client memory than Mosh, but SSH consumes less host CPU while tailing a modest log; Osewa performs better during heavy output. The current CLI supports session attachment, port forwarding, remote command execution, and host updates. Its roadmap points toward a mobile app, a multiplexer, and broader terminal support.