Terminal, Tmux, and Vim Setup for Claude Code

## Overview

Claude Code works in any terminal without configuration, but a few terminal
behaviors (multiline input, notifications, tmux, and Vim keys) often need a small
tweak. This guide walks through the common fixes.

## Multiline prompts and Shift+Enter

Enter submits your prompt. To add a newline without submitting, press `Ctrl+J`,
or type `\` then Enter. Both work everywhere with no setup.

Shift+Enter for a newline works without setup in many terminals (Ghostty, Kitty,
iTerm2, WezTerm, Warp, Apple Terminal, Windows Terminal). In VS Code, Cursor,
Devin Desktop, Alacritty, and Zed, run `/terminal-setup` once to write the
binding. In gnome-terminal and JetBrains IDEs it is unavailable; use `Ctrl+J` or
`\` then Enter.

## Configure tmux

Inside tmux, Shift+Enter and desktop notifications break by default. Add the
following to `~/.tmux.conf`, then run `tmux source-file ~/.tmux.conf`:

```bash
set -g allow-passthrough on
set -s extended-keys on
set -as terminal-features 'xterm*:extkeys'
```

`allow-passthrough` lets notifications and progress updates reach the outer
terminal; the extended-keys lines let tmux distinguish Shift+Enter from Enter.
Run `/terminal-setup` in the host terminal, not inside tmux.

## Notifications

By default Claude Code sends a desktop notification only in Ghostty, Kitty, and
iTerm2. In other terminals, set `preferredNotifChannel` to `"terminal_bell"` in
settings, or configure a Notification hook for a custom sound:

```json
{
  "hooks": {
    "Notification": [
      { "hooks": [{ "type": "command", "command": "afplay /System/Library/Sounds/Glass.aiff" }] }
    ]
  }
}
```

## Vim editor mode

Enable Vim-style editing in the prompt via `/config` -> Editor mode, or set
`editorMode` to `"vim"` in `~/.claude/settings.json`. It supports a subset of
NORMAL and VISUAL motions (`hjkl`, `v`/`V`, `d`/`c`/`y`). Enter still submits in
INSERT mode; use `o`, `O`, or `Ctrl+J` to insert a newline.

## Quick checklist

1. Newline not working? Use `Ctrl+J` or run `/terminal-setup` for your editor.
2. On tmux? Add the three lines above to `~/.tmux.conf`.
3. No alert when Claude finishes? Set `preferredNotifChannel` or add a
   Notification hook.
4. Want Vim keys? Set `editorMode: "vim"`.
5. Display flickering? Switch to fullscreen rendering with `/tui fullscreen`.

## Source

- Configure your terminal for Claude Code: https://code.claude.com/docs/en/terminal-config