DECSET 9001 — Win32 input mode (ConPTY)

frame

DEC-private-mode introducer: \x1b[? ESC [ ? (0x1B 0x5B 0x3F)

terminator (none): ST · BEL

parameters / subcommands

gotchas

• The reported events use the final byte '_' (0x5F) on a CSI: CSI ... _ — a parser must handle this private final byte, and the six numeric fields are Win32-specific (virtual-key code, scan code, unicode codepoint, key-down flag, control-key state bitmask, repeat count).
• win32-input-mode reports BOTH key-down AND key-up events and modifier-only presses, unlike normal VT input; consumers must filter to the events they care about.
• It is Windows/ConPTY-specific; non-Windows terminals do not implement it. Feature-detect (it is typically negotiated by ConPTY itself, not by arbitrary apps).
• Mode number 9001 is in the high private range and is specific to Microsoft's implementation; do not assume it is free elsewhere.
• Disable on exit so a subsequent program isn't handed verbose Win32 input records it cannot parse.

provenance

• source: https://learn.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences
• version: Microsoft Console VT sequences docs + microsoft/terminal win32-input-mode spec, retrieved 2026-05-29
• retrieved: 2026-05-29 · updated: 2026-05-29T00:00:00Z

per-fact attribution:

• #summary — https://github.com/microsoft/terminal/blob/main/doc/specs/%234999%20-%20Improved%20keyboard%20handling%20in%20Conpty.md Microsoft: DECSET 9001 enables win32-input-mode; key events are sent as CSI Vk ; Sc ; Uc ; Kd ; Cs ; Rc _ encoding the Win32 KEY_EVENT_RECORD fields (virtual-key, scan code, unicode char, key-down, control-key state, repeat count).
• #adoption — https://learn.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences Microsoft Console VT sequence docs reference the private mode used by ConPTY to forward Win32 input records to attached VT clients.

see also

• terminal-dec-private-mode/1004