Opening a new Ghostty tab on MacOS causes strange tilings with tiling window manager (yabai)

[egrefen]

Issue Description

When opening a new tab in a ghostty window while running a tiling window manager (in this case, yabai) on macOS, the WM treats the new tab as a new window. It will make the overall ghostty window half its original size, with a blank space representing the first tab's "window", and the second tab's window occupying the same footprint as if I had opened a second window. Switching to the first tab moves the (single) ghostty window to the first tab's space. Closing the tab causes the WM to tile the ghostty window correctly.

I recognize that this could just be a bug with yabai, but as it only happens when opening tabs in ghostty, I suspect it has something to do with how ghostty registers the existence of tabs to the system.

Expected Behavior

I would expect the window ghostty is in to stay the same, as shown below (tiling window manager off):

i.e. the expected behavior is that opening a tab in ghostty should not be registered by the system as a new window being open.

Actual Behavior

Opening new ghostty tabs is treated by the tiling window manager as a new window being opened, and the window is tiles accordingly. See below:

Closing the tab is treated as closing a window (and the Ghostty window with the remaining tab is re-tiled correctly).

NB: This doesn't happen with splits.

Reproduction Steps

1. Have yabai running with a tiling layout, e.g. yabai -m config layout bsp.
2. Open Ghostty. Observe that it fills the screen (or tiles as expected if other windows are opened).
3. Open a second tab in Ghostty. Observe that the window is now tiled to occupy half the space (as if the tab was a second window)
4. Switch to the first tab, and observe that the Ghostty window moves to the blank space created by the split in the previous step.
5. Close the second tab, and observe that the window now tiles correctly.

Ghostty Logs

No response

Ghostty Version

Ghostty 1.2.3

Version
  - version: 1.2.3
  - channel: stable
Build Config
  - Zig version   : 0.14.1
  - build mode    : builtin.OptimizeMode.ReleaseFast
  - app runtime   : apprt.Runtime.none
  - font engine   : font.main.Backend.coretext
  - renderer      : renderer.generic.Renderer(renderer.Metal)
  - libxev        : kqueue

OS Version Information

macOS 26.1 (25B78)

(Linux only) Display Server

None

(Linux only) Desktop Environment/Window Manager

No response

Minimal Ghostty Configuration

Happens with default config.

Additional Relevant Configuration

~/.config/yabai/yabairc

yabai -m config layout bsp

I acknowledge that:

• I have reviewed the FAQ and confirm that my issue is NOT among them.
• I have searched the Ghostty repository (both open and closed Discussions and Issues) and confirm this is not a duplicate of an existing issue or discussion.
• I have checked the "Preview" tab on all text fields to ensure that everything looks right, and have wrapped all configuration and code in code blocks with a group of three backticks (```) on separate lines.

[mitchellh]

This is well understood and discussed. Google around.

[egrefen]

Ah sorry I searched the issues, and missed that you literally have a page on your site about it 😅

Cheers for the quick response!

[rjhilgefort]

I added the following to my yabai config and restarted, but the experience still isn't great. When I open a new tab, it seems to move the window to the left side from where it was in my tiles. Is there any workaround for that @mitchellh ?

yabai -m signal --add app='^Ghostty$' event=window_created action='yabai -m space --layout bsp'
yabai -m signal --add app='^Ghostty$' event=window_destroyed action='yabai -m space --layout bsp'