System Event · Watchflows Docs

At a glance

Fires when: The chosen macOS event happens
Emits: The event, plus keys specific to it
Events: Sleep · Wake · Screen Lock · Screen Unlock · Dark Mode · Network · Volume Mount/Unmount · Bluetooth Connect/Disconnect

Set it up

Pick one event. The fields below the dropdown change with it — only the Bluetooth events have any.

The inspector for System Event. Bluetooth adds a name filter and a paired-only switch.

Configure

Field	Default	What it does
Event	Wake	Sleep, Wake, Screen Lock, Screen Unlock, Dark Mode Changed, Network Changed, Volume Mount, Volume Unmount, Bluetooth Device Connected, or Bluetooth Device Disconnected.
Device Name Filter	—	Bluetooth events. Fire only when the device name contains this text, case-insensitively. The connect and disconnect events each keep their own filter.
Paired Devices Only	On	Bluetooth events. Only devices paired with this Mac fire — what the Bluetooth menu shows. Each event keeps its own switch.
Custom Arguments	—	Extra key-value pairs merged into the payload.

Output

event and timestamp always arrive. The rest depend on which event fired.

Key	Type	Value
`event`	String	The event that fired
`timestamp`	String	When it fired, ISO 8601
`isDarkMode`	Boolean	Dark mode's new state (dark mode)
`networkType`	String	`wifi`, `cellular`, `wired`, or `other` (network)
`isConnected`	Boolean	Whether the network is up (network)
`isExpensive`	Boolean	Whether it is metered (network)
`volumeName`	String	Name of the volume (volume events)
`volumePath`	String	Where it mounted (volume events)
`deviceName`	String	The Bluetooth device's name
`deviceAddress`	String	Its MAC address, `ac-88-fd-ee-30-66`
`deviceKind`	String	headphones, audio, keyboard, mouse, gamepad, phone, computer, or unknown
`transport`	String	`classic` or `ble`
`isPaired`	Boolean	Whether it is paired with this Mac
`deviceClass`	Number	Raw Bluetooth class-of-device; 0 for BLE
`vendorID`	String	HID vendor id, when available
`productID`	String	HID product id, when available

Example: dark mode, announced

System Event watches Dark Mode Changed. Template reads {{isDarkMode}}. Notification shows which way it went.

Three nodes. The system starts the flow.

Paste this into the Flow Builder to get the same flow:

When macOS switches dark mode, notify me which mode it is now in.

Good to know

Bluetooth needs its own permission. The first time a Bluetooth flow arms, macOS asks. Denied, the trigger stays unarmed until you allow it in System Settings ▸ Privacy & Security ▸ Bluetooth.

Disconnects wait three seconds. A device that comes back inside that window — AirPods hopping to your phone and back — emits nothing. A real disconnect fires about three seconds after the drop.

Waking counts as connecting. Devices that reconnect on wake, or when the radio comes back on, fire real connect events on purpose: "when my AirPods connect, set the volume" should run then too.

Paired Devices Only exists because of phantom links. Some devices open a second, unpaired low-energy link alongside the real one — AirPods do it in their case — which would otherwise fire a duplicate connect under the same name. Turn it off to see every link, and route on {{isPaired}} or {{transport}}.

Names shift between connect and disconnect. The personalised name ("Greg's AirPods Pro") is available while connected; a disconnect may only know the generic one. Filters match either as a substring, but an exact match should use {{deviceAddress}}.