Vim Mode

cmux includes a built-in Vim mode for the chat input, providing familiar Vim-style editing for power users.

Enabling Vim Mode

Vim mode is always enabled. Press ESC to enter normal mode from insert mode.

Modes

Insert Mode (Default)

This is the default mode when typing in the chat input
Type normally, all characters are inserted
Press ESC or Ctrl-[ to enter normal mode

Normal Mode

Command mode for navigation and editing
Indicated by "NORMAL" text above the input
Pending commands are shown (e.g., "NORMAL d" when delete is pending)
Press i, a, I, A, o, or O to return to insert mode

Basic Movement

h - Move left one character
j - Move down one line
k - Move up one line
l - Move right one character

Word Movement

w - Move forward to start of next word
W - Move forward to start of next WORD (whitespace-separated)
b - Move backward to start of previous word
B - Move backward to start of previous WORD
e - Move to end of current/next word
E - Move to end of current/next WORD

Line Movement

0 - Move to beginning of line
_ - Move to first non-whitespace character of line
$ - Move to end of line
Home - Same as 0
End - Same as $

When moving up/down with j/k, the cursor attempts to stay in the same column position. If a line is shorter, the cursor moves to the end of that line, but will return to the original column on longer lines.

Entering Insert Mode

i - Insert at cursor
a - Append after cursor
I - Insert at beginning of line
A - Append at end of line
o - Open new line below and insert
O - Open new line above and insert

Editing Commands

Simple Edits

x - Delete character under cursor
p - Paste after cursor
P - Paste before cursor

Undo/Redo

u - Undo last change
Ctrl-r - Redo

Line Operations

dd - Delete line (yank to clipboard)
yy - Yank (copy) line
cc - Change line (delete and enter insert mode)

Operators + Motions

Vim's power comes from combining operators with motions. All operators work with all motions:

Operators

d - Delete
c - Change (delete and enter insert mode)
y - Yank (copy)

Motions

w - To next word
b - To previous word
e - To end of word
$ - To end of line
0 - To beginning of line
_ - To first non-whitespace character

Examples

dw - Delete to next word
de - Delete to end of word
d$ - Delete to end of line
cw - Change to next word
ce - Change to end of word
c0 - Change to beginning of line
y$ - Yank to end of line
ye - Yank to end of word
yy - Yank line (doubled operator)

Shortcuts

D - Same as d$ (delete to end of line)
C - Same as c$ (change to end of line)

Text Objects

Text objects let you operate on semantic units:

Inner Word (iw)

diw - Delete inner word (word under cursor)
ciw - Change inner word
yiw - Yank inner word

Text objects work from anywhere within the word - you don't need to be at the start.

Visual Feedback

Cursor: Thin blinking cursor in insert mode, solid block in normal mode
Mode Indicator: Shows current mode and pending commands (e.g., "NORMAL d" when waiting for motion)

Keybind Conflicts

ESC Key

ESC is used for:

Exiting Vim normal mode (highest priority)
NOT used for canceling edits (use Ctrl-Q instead)
NOT used for interrupting streams (use Ctrl-C instead)

Tips

Learn operators + motions: Instead of memorizing every command, learn the operators (d, c, y) and motions (w, b, $, 0). They combine naturally.
Use text objects: ciw to change a word is more reliable than cw because it works from anywhere in the word.
Column preservation: When navigating up/down, your column position is preserved across lines of different lengths.

Not Yet Implemented

Features that may be added in the future:

ge - Backward end of word motion
f{char}, t{char} - Find character motions
i", i', i(, i[, i{ - More text objects
2w, 3dd, 5x - Count prefixes
Visual mode - Character, line, and block selection
Macros - Recording and replaying command sequences
Marks - Named cursor positions

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