Ports
When a Service is up, taken ports, and the Ports view.
A Service’s Port is the one TCP port it is expected to listen on. The command gets it as $PORT (%PORT% in cmd); localhost never rewrites command lines or adds framework flags.
When a Service is Running
With a Port, a Service counts as Running once the port accepts connections. After 30 seconds it is Running anyway, with a warning that clears when the port opens. Without a Port, it is Running after about 1.5 seconds alive.
When a port is taken
Before starting a Service with a Port, localhost checks who holds it. If something else does, the Service can start on the next free port (it gets that port as $PORT for this Run; the configured Port doesn’t change), or you choose: stop the other process and start, start on another port, or cancel.
Settings turns the automatic move off; a Service’s Port can change switch turns it off for that Service. A Service that others depend on never moves, and neither does one whose port is held by something in the same Project.
Open in Browser
Open in Browser (⇧⌘O) opens the Service’s URL with its port moved to the Run’s, or http://localhost:<port>, or else the first local URL the Run printed.
The Ports view
The Ports view (⌘0) lists every process listening on a TCP port and whom it belongs to: one of your Services, a process running inside one of your Projects’ folders, or nothing localhost knows (other apps and system services are folded below). Select one and press ⌘. to stop it; localhost asks first for anything it didn’t start.