kitten-@-set...round-opacity(1)

📦
version 0.49.2 · 12 versions
, in arch rolling, nixpkgs unstable

💅 kitten @ set-background-opacity — like, the vibes command for window transparency

okay so this is a page from the kitten Manual, bestie — the kitten @ set-background-opacity(1) one, and it's literally the glow-up button for your windows. Let's get into it 🫶

✨ Name

kitten-@-set-background-opacity — Set the background opacity 🔥

🎀 Usage

kitten @ set-background-opacity  OPACITY

🦋 Description

So basically: this sets the background opacity for the windows you specify. The way it only works is if you've turned on dynamic_background_opacity in kitty.conf — no cap, if that's not on, this command is just gonna sit there looking cute and doing nothing 💀

Also important: the background opacity affects all kitty windows in a single OS window. Like, it's a whole-OS-window vibe, not a per-pane vibe. 🪟

Example, because we love a visual:

kitten @ set-background-opacity 0.5

🌸 Options

  • --all, -a [=no] — so by default, background opacity only gets changed for the currently active OS window. This option makes the background opacity change happen in all windows instead. slay ✨
  • --toggle [=no] — when you specify this, the background opacity for the matching OS windows gets reset to default if it's currently equal to the specified value; otherwise it gets set to the specified value. it's giving light switch energy 💅
  • --match, -m — the window to match, bestie. Match specs look like field:query. field can be one of: id, title, pid, cwd, cmdline, num, env, var, state, neighbor, session and recent. And query is the expression to match — expressions can be a number or a regular expression, and you can combine them with Boolean operators 🧚

The special value all matches all windows. periodt.

For the numeric fields — id, pid, num and recent — the expression is interpreted as a number, not a regular expression. Negative values for id match from the highest id number down; in particular, -1 is the most recently created window. 🥇

The field num refers to the window position in the current tab, starting from zero and counting clockwise (same order the windows get reported by the kitten @ ls command, iykyk).

The window id of the current window is available as the KITTY_WINDOW_ID environment variable. 🪪

The field recent refers to recently active windows in the currently active tab — zero is the currently active window, one is the previously active window, and so on.

The field neighbor refers to a neighbor of the active window in the specified direction, which can be: left, right, top or bottom. 🧭

The field session matches windows that were created in the specified session. Use the expression ^$ to match windows that were not created in a session, . to match the currently active session, and ~ to match either the currently active session or the last active session when no session is active. 🌀

When you're using the env field to match on environment variables, you can specify just the environment variable name, or a name and a value — like env:MY_ENV_VAR=2, for example.

Similarly, the var field matches on user variables set on the window. You can specify a name, or a name and value, just like with the env field. 🏷️

The field state matches on the state of the window. Supported states are: active, focused, needs_attention, parent_active, parent_focused, focused_os_window, self, overlay_parent. Active windows are the windows that are active in their parent tab. There's only one focused window, and it's the window that keyboard events get delivered to — if no window is focused, the last focused window is matched. The value focused_os_window matches all windows in the currently focused OS window. The value self matches the window in which the remote control command is run. And the value overlay_parent matches the window that's under the self window, when the self window is an overlay. 👑

Note that you can use the kitten @ ls command to get a list of windows. super handy, fr fr.

  • --match-tab, -t — the tab to match. Match specs are of the form field:query, where field can be one of: id, index, title, window_id, window_title, pid, cwd, cmdline, env, var, state, session and recent. query is the expression to match — a number or a regular expression, combinable with Boolean operators. 🌈

The special value all matches all tabs. 💯

For numeric fields — id, index, window_id, pid and recent — the expression is interpreted as a number, not a regular expression. Negative values for id/window_id match from the highest id number down; in particular, -1 is the most recently created tab/window.

When you use title or id, first a matching tab is looked for, and if that's not found a matching window is looked for, and the tab for that window is used. sneaky but iconic.

You can also use window_id and window_title to match the tab that contains the window with the specified id or title. 🪟

The index number is used to match the nth tab in the currently active OS window. The recent number matches recently active tabs in the currently active OS window — zero being the currently active tab, one the previously active tab, and so on.

The field session matches tabs that were created in the specified session. Use the expression ^$ to match windows that were not created in a session, . to match the currently active session, and ~ to match either the currently active session or the last active session when no session is active.

When using the env field to match on environment variables, you can specify just the environment variable name, or a name and value — like env:MY_ENV_VAR=2. Tabs containing any window with the specified environment variables are matched. Similarly, var matches tabs containing any window with the specified user variable. 🍓

The field state matches on the state of the tab. Supported states are: active, focused, needs_attention, parent_active, parent_focused and focused_os_window. Active tabs are the tabs that are active in their parent OS window. There's only one focused tab, and it's the tab that keyboard events get delivered to — if no tab is focused, the last focused tab is matched. The value focused_os_window matches all tabs in the currently focused OS window.

Note that you can use the kitten @ ls command to get a list of tabs. yw 💖

  • --help, -h [=no] — Show help for this command. the classic.

👑 Global options

  • --to — an address for the kitty instance to control 🎯. Corresponds to the address given to the kitty instance via the --listen-on option or the listen_on setting in kitty.conf. If it's not specified, the environment variable KITTY_LISTEN_ON is checked. If that's also not found, messages get sent to the controlling terminal for this process — i.e. they'll only work if this process is run within a kitty window. 🙈
  • --password — a password to use when contacting kitty. This makes kitty ask the user for permission to perform the specified action, unless the password has been accepted before or is pre-configured in kitty.conf. To use a blank password, specify --use-password as always. 🔐
  • --password-file [=rc-pass] — a file from which to read the password. Trailing whitespace is ignored. Relative paths are resolved from the kitty configuration directory. Use - to read from STDIN. Use fd:num to read from the file descriptor num. Used if no --password is supplied. Defaults to checking for the rc-pass file in the kitty configuration directory. 📄
  • --password-env [=KITTY_RC_PASSWORD] — the name of an environment variable to read the password from. Used if no --password-file is supplied. Defaults to checking the environment variable KITTY_RC_PASSWORD. 🌱
  • --use-password [=if-available] — if no password is available, kitty will usually just send the remote control command without a password. This option can force it to always or never use the supplied password. If it's set to always and no password is provided, the blank password is used. ⚡

Choices: if-available, always, never

ok that's literally the whole page, bestie 🫶 go forth and make your windows translucent, no cap 💜

and finally, the cute little sign-off at the bottom: this is from version 0.49.2, dated Oct 01, 2026 — the kitten-@-set-background-opacity(1) page, mwah 💅✨🎀

📦 where this page comes from