twin helps keep two machines' configuration aligned. A sync-file is just Markdown: the prose says why a path is synced, and fenced YAML blocks define what to do. rsync does the copying. When both sides changed since the last sync, twin shows a diff and asks before overwriting. A target is a local path, a mounted volume, or user@host:/path over ssh, and twin treats all three the same. Interactive selection runs through fzf with a rendered Markdown preview; the same sync-files drive scriptable status, dry-run and sync commands.