Vant is software you fetch and run yourself; there is no central Vant server to be down. What exists publicly are these surfaces, checked live from your browser when the board mounts.

Honest limits: these checks answer from your browser, so a corporate proxy or an offline network can make a healthy surface look unreachable, the reverse is never true (a reported-unreachable surface fails loudly, it does not fail hidden). No result is stored anywhere; nothing here phones home.