offsidepi uses the Kitty keyboard protocol for reliable modifier key detection. Most modern terminals support this protocol, but some require configuration.
Work out of the box.
offsidepi enables enhanced key reporting when available. If Terminal.app still sends plain Return for Shift+Enter, offsidepi uses a local macOS modifier fallback to treat that Return as Shift+Enter.
This fallback only works when offsidepi runs on the same Mac as Terminal.app. It cannot detect the local keyboard over remote SSH.
Add to your Ghostty config (~/Library/Application Support/com.mitchellh.ghostty/config on macOS, ~/.config/ghostty/config on Linux):
keybind = alt+backspace=text:\x1b\x7f
Older Claude Code versions may have added this Ghostty mapping:
keybind = shift+enter=text:\n
That mapping sends a raw linefeed byte. Inside offsidepi, that is indistinguishable from Ctrl+J, so tmux and offsidepi no longer see a real shift+enter key event.
If Claude Code 2.x or newer is the only reason you added that mapping, you can remove it, unless you want to use Claude Code in tmux, where it still requires that Ghostty mapping.
offsidepi binds Ctrl+J as a default newline alias, so Shift+Enter keeps working in tmux via that remap without extra offsidepi configuration.
WezTerm usually works out of the box for Shift+Enter via xterm modifyOtherKeys. To use the Kitty keyboard protocol explicitly, create ~/.wezterm.lua:
local wezterm = require 'wezterm'
local config = wezterm.config_builder()
config.enable_kitty_keyboard = true
return configOn macOS, WezTerm binds Option+Enter to fullscreen by default. To use Option+Enter for offsidepi follow-up queueing, add this key override:
local wezterm = require 'wezterm'
local config = wezterm.config_builder()
config.keys = {
{
key = 'Enter',
mods = 'ALT',
action = wezterm.action.SendString('\x1b[13;3u'),
},
}
return configIf you already have a config.keys table, add the entry to it.
On WSL, WezTerm may require a visible hardware cursor for IME candidate window positioning. If CJK IME candidates do not follow the text cursor, set PI_HARDWARE_CURSOR=1 before running offsidepi or set showHardwareCursor to true in settings.
Alacritty usually works out of the box for Shift+Enter. On macOS, Option+Enter may arrive as plain Enter. To use Option+Enter for offsidepi follow-up queueing, add to ~/.config/alacritty/alacritty.toml:
[[keyboard.bindings]]
key = "Enter"
mods = "Alt"
chars = "\u001b[13;3u"Restart Alacritty after changing the config.
VS Code 1.109.5 and newer enable Kitty keyboard protocol in the integrated terminal by default, so Shift+Enter should work out of the box.
VS Code versions older than 1.109.5 need an explicit terminal keybinding for Shift+Enter.
keybindings.json locations:
- macOS:
~/Library/Application Support/Code/User/keybindings.json - Linux:
~/.config/Code/User/keybindings.json - Windows:
%APPDATA%\\Code\\User\\keybindings.json
Add to keybindings.json:
{
"key": "shift+enter",
"command": "workbench.action.terminal.sendSequence",
"args": { "text": "\u001b[13;2u" },
"when": "terminalFocus"
}Add to settings.json (Ctrl+Shift+, or Settings → Open JSON file) to forward the modified Enter keys offsidepi uses:
{
"actions": [
{
"command": { "action": "sendInput", "input": "\u001b[13;2u" },
"keys": "shift+enter"
},
{
"command": { "action": "sendInput", "input": "\u001b[13;3u" },
"keys": "alt+enter"
}
]
}Shift+Enterinserts a new line.- Windows Terminal binds
Alt+Enterto fullscreen by default. That prevents offsidepi from receivingAlt+Enterfor follow-up queueing. - Remapping
Alt+EntertosendInputforwards the real key chord to offsidepi instead.
If you already have an actions array, add the objects to it. If the old fullscreen behavior persists, fully close and reopen Windows Terminal.
These terminals have limited escape sequence support. Modified Enter keys like Ctrl+Enter and Shift+Enter cannot be distinguished from plain Enter, preventing custom keybindings such as submit: ["ctrl+enter"] from working.
For the best experience, use a terminal that supports the Kitty keyboard protocol:
The built-in terminal has limited escape sequence support. Shift+Enter cannot be distinguished from Enter in IntelliJ's terminal.
If you want the hardware cursor visible, set PI_HARDWARE_CURSOR=1 before running offsidepi (disabled by default for compatibility).
Consider using a dedicated terminal emulator for the best experience.