[BUG] Kitty keyboard protocol: Numpad Enter and Shift+Space not decoded (Ghostty + German keymap)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Since updating to Claude Code 2.1.x (the version that added native Kitty keyboard protocol support for Shift+Enter), two keys no longer work correctly in Ghostty:

1. Numpad Enter outputs the literal string [57414;129u instead of submitting/newline

2. Shift+Space outputs the literal word space instead of a space character

These keys work fine outside of Claude Code (in the same terminal, same session). The issue started immediately after the update that enabled native Kitty keyboard protocol support.

What Should Happen?

• Numpad Enter should behave like regular Enter (submit message or insert newline depending on context)
• Shift+Space should insert a space character

Error Messages/Logs

Steps to Reproduce

1. Use Ghostty terminal on Linux
2. Use German keyboard layout (de-latin1-nodeadkeys)
3. Run claude
4. In the input field, press Numpad Enter → observe [57414;129u appears as literal text
5. In the input field, hold Shift and press Spacebar → observe space appears as literal text

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.0.x (before Kitty keyboard protocol was enabled in 2.1.0)

Claude Code Version

claude --version 2.1.1 (Claude Code)

Platform

Anthropic API

Operating System

Other Linux

Terminal/Shell

Other

Additional Information

The escape sequences being sent are valid Kitty keyboard protocol:

• 57414 is the Kitty protocol keycode for KP_ENTER (numpad enter)
• The [<keycode>;<modifiers>u format is the CSI u encoding

Ghostty is correctly sending these sequences. Claude Code enabled Kitty keyboard protocol in 2.1.0 to make Shift+Enter work natively, but the decoder doesn't handle all keycodes - specifically numpad keys and the shift+space combo.

https://sw.kovidgoyal.net/kitty/keyboard-protocol/#functional-key-definitions

Workaround

Adding these keybinds to Ghostty config (~/.config/ghostty/config) forces legacy sequences for these specific keys:

keybind = shift+space=text:\x20
keybind = kp_enter=text:\r

This works but shouldn't be necessary.

Related Issues

• #5757 - Similar issue with Shift+Enter sending [27;2;13~ (marked as duplicate, supposedly fixed in 2.1.0)
• #1758 - Original feature request for Kitty protocol support