win32-input-mode

Status: Vendor-private, defined by Microsoft for ConPTY.

win32-input-mode is a keyboard encoding that carries a full Windows KEY_EVENT_RECORD over the PTY. It exists because the Windows console API gives applications more than a byte stream: virtual key codes, scan codes, key-up events, and control-key state. When Windows Terminal or another ConPTY host sits in front of a console application, the bytes it sends must be turned back into those records without loss, and no VT encoding could express them.

Syntax

CSI ? 9001 h     enable win32-input-mode
CSI ? 9001 l     disable win32-input-mode
CSI Vk ; Sc ; Uc ; Kd ; Cs ; Rc _

Field	Meaning
Vk	Virtual key code (wVirtualKeyCode)
Sc	Scan code (wVirtualScanCode)
Uc	Unicode character (UnicodeChar), as a decimal code unit
Kd	Key down flag: 1 press, 0 release
Cs	Control key state bit mask (dwControlKeyState)
Rc	Repeat count

Omitted fields default to 0. The final byte _ was chosen because it is unused by other keyboard encodings.

Behavior

Once enabled, every key event, including releases and modifier-only presses, arrives as one _ sequence, and the legacy encodings stop. The receiver reconstructs a Windows input record and feeds it to the console input buffer, so a console application sees exactly what it would see on a local console.

The mode is intended for ConPTY-to-host communication. A Unix application gains nothing from it and should not enable it; the ordinary VT encodings remain available in ConPTY sessions without it.

Relationship to the Kitty protocol

Both encodings report press and release and both can carry the produced text, but they differ in intent. win32-input-mode is a transport for platform key records, keyed by Windows virtual key and scan codes. The Kitty protocol is platform-neutral and keyed by Unicode code points. An emulator on Windows may implement both: win32-input-mode to talk to ConPTY, and the Kitty protocol for applications that request it.

Probe

Inside Windows Terminal or WezTerm on Windows:

printf '\033[?9001h'; cat -v; printf '\033[?9001l'

Each key press and release prints a ^[[...;...;...;1;...;1_ or ...;0;..._ line. On other emulators nothing changes.

Sources

• Improved keyboard handling in Conpty (spec #4999)
• KEY_EVENT_RECORD structure

Compatibility

Feature support by terminal. Imported claims have not been reverified; unknown is not unsupported.

Feature / stable ID	Alacritty	Apple Terminal	ConPTY (conhost)	Contour	DomTerm	foot	Ghostty	iTerm2	kitty	Konsole	mintty	mlterm	PuTTY	Revenant	RLogin	st	tmux	rxvt-unicode	VTE	wayst	WezTerm	Windows Terminal	xterm	xterm.js
win32-input-mode dec-mode-9001-win32-input	Unknown	UnknownImported · unverified	SupportedImported · unverified	UnknownImported · unverified	Unknown	UnknownImported · unverified	UnknownImported · unverified	UnknownImported · unverified	UnknownImported · unverified	UnknownImported · unverified	Unknown	Unknown	UnknownImported · unverified	Unknown	Unknown	Unknown	UnknownImported · unverified	Unknown	UnknownImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	UnknownImported · unverified	UnknownImported · unverified