Screens

A screen is anything with a terminal: a phone, another computer, an old laptop, a pocket terminal. None of them hold state — the deck stays on the brain — so adding one is one line, and removing one is deleting that line.

phosphor phone (also p in the DECK tab) prints all of this for your own deck, with the phone’s line as a QR to scan with the camera.

A phone or tablet (Android + Termux)

pkg install -y openssh
ssh you@brain '~/.local/bin/phosphor phone' | sh

The brain answers with a script made for your deck: the phone’s ssh key (your password one last time), a deck command, a Termux:Widget icon, and extra keys (KEYBOARD, EDIT, ZOOM, EXIT). Run it again any time; it only adds what’s missing, and a phone with the kit’s older keys gets EDIT too.

Another computer (Linux, macOS, WSL)

ssh you@brain '~/.local/bin/phosphor screen' | sh

The same thing without Termux: a key, and a deck command in ~/.local/bin that reconnects by itself. Nothing else is installed: an old laptop makes a fine screen.

Anything that only has ssh

ssh -t you@brain ~/.local/bin/deck

An old terminal, an ssh app on an iPad, a pocket terminal. The full path matters: a plain ssh command gets no login shell, so a bare deck isn’t found. This is also what the kits above end up running.

ssh, not mosh

mosh survives sleep and network changes but doesn’t carry the mouse, so no touch. The deck command uses ssh and reconnects by itself when the link drops (every 3s until the network is back) and when the deck restarts; leaving with EXIT or Ctrl-q ends it. If Android killed Termux, tap the icon.

Narrow screens: Alt-z (ZOOM) gives one pane the whole screen. With headscale, the phone’s Tailscale app must log into your headscale server; phosphor phone prints which.

Managing screens from the deck

zellij ties a tab’s whole grid to the smallest attached client’s viewport, with no setting to change that – so a phone looking at the same tab as your PC squeezes everyone’s pane down to phone size. phosphor screens (also v in the DECK tab) lists every screen actually attached (where it’s from, how long it’s been idle) and lets you kick one loose with x (twice, on purpose): it just ends that one ssh connection, and the deck wrapper above notices the drop and reconnects on its own in a few seconds. Not a way to ban a device – a way to force one reconnect without walking over to whichever screen is in the way.

Notifications when you’re not attached

A screen only shows what’s happening while you’re looking at it. For when you’re not: install the ntfy app (Play Store, F-Droid, or pkg install ntfy in Termux), turn on [push] in the profile (see profile), then

phosphor push --qr

and scan the code in the ntfy app (its own “+” → scan a QR, not the phone’s camera app) to subscribe – no typing the server or topic in by hand. From then on phosphor notify --push, a fleet host going down or coming back, and a chat mention all ring and vibrate the phone, Termux open or not.

A glance instead of the whole deck

Some screens are too small for a full attach: a Pi with a small display sitting on a shelf, an old e-reader, anything you’d rather glance at than drive. ssh -t you@brain ~/.local/bin/phosphor glance skips zellij entirely and prints a read-only summary that refreshes on its own – the fleet’s problem hosts (or “all N ok”), unread mentions, open todos – until Ctrl-C. Nothing to attach, nothing to detach: it’s just a command, so any cron job or kiosk script that can run one over ssh can drive that little screen.