# window_index

Source: https://libtmux.org/en/tmux/3.2a/catalog/formats/window_index/

> Index of window

format variable tmux3.2a

Index of window

* Scope

  Describes the window being formatted

* Type

  Text

* Short form

  `#I`

* Usage

  `#{window_index}`

## Description[#](https://libtmux.org/en/tmux/3.2a/catalog/formats/window_index/#description)

Index of window

## Releases[#](https://libtmux.org/en/tmux/3.2a/catalog/formats/window_index/#releases)

* [tmux 3.7c](https://libtmux.org/en/tmux/3.7c/catalog/formats/window_index/) : present
* [tmux 3.2a](https://libtmux.org/en/tmux/3.2a/catalog/formats/window_index/) : present

## Source[#](https://libtmux.org/en/tmux/3.2a/catalog/formats/window_index/#source)

* Defined in

  [`format.c:2933`](https://github.com/tmux/tmux/blob/3b929f332aafa7f1080eacc31feb11ffbb1d1841/format.c#L2933)

* C source reference

  [`format_cb_window_index`](https://libtmux.org/en/tmux/3.2a/reference/c-function-format-c-format_cb_window_index/)

* CLI Manual

  [Original manual entry](https://libtmux.org/en/tmux/3.2a/manual/full/#window_index)

## Used by[#](https://libtmux.org/en/tmux/3.2a/catalog/formats/window_index/#used-by)

Library documentation that names this format variable.

* PowerShell

  [`LibTmux.Workspace\Import-TmuxWorkspace`](https://libtmux.org/en/powershell/latest/workspace/reference/libtmux-workspace-import-tmuxworkspace/)

* Julia

  [`LibTmux.FormatUpdate`](https://libtmux.org/en/julia/latest/reference/libtmux-formatupdate/)

* Python

  [`libtmux_mcp.tools.session_tools.select_window`](https://libtmux.org/en/py/latest/mcp/reference/libtmux_mcp-tools-session_tools-select_window/), [`libtmux_mcp.tools.window_tools.get_window_info`](https://libtmux.org/en/py/latest/mcp/reference/libtmux_mcp-tools-window_tools-get_window_info/), [`libtmux.neo._best_winlink`](https://libtmux.org/en/py/latest/reference/libtmux-neo-_best_winlink/), [`libtmux.options.convert_values`](https://libtmux.org/en/py/latest/reference/libtmux-options-convert_values/)

* TypeScript

  [`builder.applyWorkspace`](https://libtmux.org/en/ts/latest/workspace/reference/builder-applyworkspace/)

* Go

  [`tmux.FormatValues.WindowIndex`](https://libtmux.org/en/go/latest/reference/tmux-formatvalues-windowindex/)