Hi HN, Recently I wasted several hours wrangling my dev environment only to find out that the browser frontend was talking to the wrong version of the backend. This got me thinking…

Set every port to 0 and start your dev server. Port Zero gives each process or container a stable domain — no port to remember, no EADDRINUSE, ever. Each worktree's dev server gets its own self-explanatory URL — no port juggling between branches, no collisions. Local domains stop at your machine. A cloud tunnel takes the same app to your phone, a tablet, or anyone you choose — HTTPS included. Port Zero starts local and free, and grows as far as you need. Pick what brings you here — or just explore. Set every port to 0. Each process and container gets a stable *.portzero.local domain — no EADDRINUSE, no port map, no bookkeeping. Free and open source. AI agents and git worktrees each start their own dev server. Every one gets a self-explanatory URL, so N parallel builds never fight over :3000 — and your coding agent can manage it all over MCP. *.portzero.local can't reach a phone or tablet. A cloud tunnel takes the same app across the device boundary with HTTPS — tap the URL on any device and iterate. Works per worktree, too: every branch can get its own cloud URL. Give any local app a public HTTPS URL — on your own domain if you like. Flat pricing: no metered bandwidth, no per-request pricing, no overage charges.