Hotline on a server

hotline serve runs the desk with no window: the same room, teammates, schedules and computers as the desktop app, on a Linux machine you reach over SSH. Your phone is the window. Teammates keep working while nobody is connected, and the phone picks up where they are when you open it.

A server is not self-explanatory the way the desktop app is, so this section goes in order:

1. Install: the binary, a service account, and a systemd unit that listens on one address.
2. Pair your phone: hotline pair prints a QR code and your phone scans it.
3. Connect a model: a one-time step on the server, so your teammates have something to run on.
4. Teammates and computers: add teammates from the phone, and give one a computer.
5. Day to day: status, logs, restarts, updates, and what lives where.
6. Troubleshooting: what the messages mean.

What you need

• A Linux machine, x86_64 or arm64, with systemd.
• An address your phone can reach: the same network or VPN, or a public address or name.
• Docker or Podman, only if a teammate will have a computer.
• Node, if your teammates will run harnesses installed through npx.

How the phone and the server trust each other

Pairing gives the phone the server’s own key, from the QR code. Every connection after that is a sealed channel (Noise) to that key, inside TLS. TLS only carries the bytes, so a self-signed certificate is fine, and so is a proxy in front. A server that cannot prove it holds the key from the QR never gets a connection. No password or token travels over the network. The server knows each paired phone by the phone’s key, and forgets it when you revoke it.