single instance
Single-instance behavior routes subsequent launches to an existing application instance.
Use this when Launching an app twice starts competing windows or local services.
without the term
“If you double-click a file when the app is already open, a second copy of the app launches. Can you make it open the file in the existing window instead?”
with the term · How do you ask a model for single instance?
Enforce this app’s single-instance behavior. Test simultaneous launches and forwarding a file or deep link to the existing instance.
What is single instance?
The second launch of the app hands its arguments, such as a file to open or a link, to the window already running, then exits.
Why does single instance matter when vibe coding?
A second process can lose the user’s requested file while handing off control.
How do you do single instance?
Acquire the instance boundary early and handle subsequent activation messages explicitly.
What goes wrong with single instance?
Focusing the old window but discarding the new launch payload.