more flexible `copy-on-select` and `middle-click-action`

[jcollie]

copy-on-select should be modified to be more flexible. It should support none, primary, clipboard, both
The default should be primary. true will be an alias for primary, false will be an alias for none. On systems that do not have the concept of a primary clipboard primary should be a no-op.

middle-click-action should be modified with the options ignore, paste-primary, paste-clipboard. On systems that do not have the concept of a primary clipboard paste-primary should be a no-op.

Modifying copy-on-select or middle-click-action should have no effect on the operation of the other.

Verbiage around copying/pasting should be update to refer to only primary and clipboard since those are the standard terms. selection seems a bit too ambiguous.

Discussed in #12573

^{Originally posted by mohshami May 3, 2026}
In Linux, terminal emulators have the following behavior

Middle-click always pastes from the PRIMARY/SELECTION clipboard.
Paste action (Normally ctrl+shift+V) always pastes from CLIPBOARD.

This behavior persists regardless of the copy-on-select option (for those terminal emulators that support it)

That behavior was added to Ghostty in #2347, along with the documentation below

# Whether to automatically copy selected text to the clipboard. `true`
# will prefer to copy to the selection clipboard, otherwise it will copy to
# the system clipboard.
#
# The value `clipboard` will always copy text to the selection clipboard
# as well as the system clipboard.
#
# Middle-click paste will always use the selection clipboard. Middle-click
# paste is always enabled even if this is `false`.
#
# The default value is true on Linux and macOS.
copy-on-select = true

#12443 broke that, making Ghostty behave differently from all other emulators on Linux.

I am not sure how terminal emulators behave in MacOS, I think #12443 should be limited to MacOS or a 4th option needs to be added to copy-on-select to modify CLIPBOARD but keep middle click paste from SELECTION.

Since #12443 is scheduled for 1.4, I think more people will see the difference once that out

I can't stress enough how much I appreciate the colossal amount of work everyone is putting. Thank you all

[00-kat]

those are the standard terms. selection seems a bit to ambiguous.

Yeah as far as I know, “selection“ is the collective term for “primary” and “clipboard”. Not sure if it's called selection on macOS though, I vaguely recall the word “pasteboard” from before.

[mohshami]

From https://shallowsky.com/blog/linux/x-selection.html

The Primary Selection: When you sweep your mouse across some words to highlight them, or double-click to highlight a word, or triple-click to highlight a line, whatever you've highlighted is now in the primary selection.

The Clipboard Selection: The clipboard selection works pretty much the same as it does on Mac and Windows. Highlight something (now it's the primary selection), then you type Ctrl-C or use the Edit->Copy menu, and now it's the clipboard selection as well as the primary selection. You can select something else, changing the primary selection, but whatever you copied is still the clipboard. Paste also works the same way: type Ctrl-V or use the Edit->Paste menu, and the clipboard selection will be inserted wherever your active text cursor is (not where the mouse is).

The proposal here allows for both behaviors (the original and the one #12443 introduced). I will be closing the discussion.

Thank you so much

[vcastellm]

No sure if this fully related but the previous configuration that worked for me stopped working in latest update:

copy-to-clipboard = clipboard
clipboard-read = allow
clipboard-write = allow

Now with copy-to-clipboard = true the default, using tmux the copy on select in opencode doesn't work anymore.

Just wanted to leave my report as a way to reproduce.