notes on dantrolene ・ rx no.003 ・ for macOS

You're home
and it locks anyway.

dantrolene keeps your Mac from locking the screen while you're sitting right in front of it, on the WiFi you call home. on every other network, it locks like it should.

See the code

macOS 26 · open source · MIT

The Dantrolene popover at home: the arc-house mark and ‘Preventing lock’ on the home network, with mode and display-sleep selectors — **home** ・ on your wifi, the screen never locks

The Dantrolene popover away from home: the mark folded into a padlock, ‘Locking normally’ — **away** ・ anywhere else, it locks like it should

01 ・ the ailment

The screen locked
while you were reading it.

lock timeouts make sense on a train, in an office, anywhere a stranger might walk past. at home they're a reflex with no predator. the screen seizes up mid-paragraph, mid-movie, and asks for the password it asked an hour ago.

Dantrolene, the drug, is a muscle relaxant: it's what you give a body that clenches when it shouldn't. the app watches which WiFi you're on. on your home network it holds a display assertion, so the lock chain never starts. on any other network, nothing. the reflex stays.

it still pretends to sleep. after your usual idle time the display dims and goes dark on schedule. touch anything and the light comes back, with no password between you and the sentence you were reading.

and it's polite: when Zoom or a presentation holds its own display assertion, dantrolene notices and backs off.

The Dantrolene menu bar popover at home, dark mode: the arc-house mark, ‘Preventing lock’ on the home network, with mode and display-sleep selectors and a lid-hold chip.

plate i ・ the mark, reading the network to decide you're home.

02 ・ the label

Directions
for use.

a mark in the menu bar. open it, mark your network as home, and that's it. three modes: automatic, always on, off. that's everything there is to learn.

aknows home by the network name: checked locally, stored locally.
bsimulated sleep: dims and darkens on idle, wakes at a touch.
cconflict-aware: backs off when another app holds the display.
dlaunch at login, then forget it exists.
enothing phones home. there is no home to phone but yours.
+pairs with Adrafinil: close the lid and the Mac stays awake at home — even with no external display attached — and sleeps the moment you leave.
fMIT. small enough to read in one sitting.

and it stacks. with Adrafinil installed, dantrolene holds the whole machine awake through a closed lid while you're home — no external display, no clamshell trickery — so a MacBook keeps working shut on the shelf, and sleeps again the moment you leave the network.

The Dantrolene popover away from home, dark mode: the mark folded into a padlock, ‘Locking normally’ — the Mac locks as usual.

plate ii ・ somewhere else: the mark folds shut, locked as prescribed.

服用注意・ side effects macOS only reveals WiFi names to apps with Location Services permission. that's Apple's rule; the app wants the network's name, not where you are. an SSID is a name, not a proof: anyone can call their hotspot what you call home, so treat this as comfort, not security. the dimming rides on private frameworks, so a macOS update may break it someday.

For the Macs
that live at home.

macOS · open source · rx no.003

See the code

You're homeand it locks anyway.

The screen lockedwhile you were reading it.

Directionsfor use.

For the Macsthat live at home.

You're home
and it locks anyway.

The screen locked
while you were reading it.

Directions
for use.

For the Macs
that live at home.