# Paneru
A sliding, tiling window manager for MacOS.
## About
Paneru is a MacOS window manager that arranges windows on an infinite strip,
extending to the right. A core principle is that opening a new window will
**never** cause existing windows to resize, maintaining your layout stability.
Each monitor operates with its own independent window strip, ensuring that
windows remain confined to their respective displays and do not "overflow" onto
adjacent monitors.
<video src="https://github.com/user-attachments/assets/cbc2e820-635f-408b-923a-6cb47c44704c"></video>
## Why Paneru?
- **Niri-like Behavior on MacOS:** Inspired by the user experience of [Niri],
Paneru aims to bring a similar scrollable tiling workflow to MacOS.
- **Works with MacOS workspaces:** You can use existing workspaces and switch
between them with keyboard or touchpad gestures - with a separate window strip
on each. Drag and dropping windows between them works as well.
- **Focus follows mouse on MacOS:** Very useful for people who would like to
avoid an extra click.
- **Sliding windows with touchpad:** Using a touchpad is quite natural for
navigation of the window pane.
- **Optimal for Large Displays:** Standard tiling window managers can be
suboptimal for large displays, often resulting in either huge maximized
windows or numerous tiny, unusable windows. Paneru addresses this by
providing a more flexible and practical arrangement.
- **Improved Small Display Usability:** On smaller displays (like laptops),
traditional tiling can make windows too small to be productive, forcing users
to constantly maximize. Paneru's sliding strip approach aims to provide a
better experience without this compromise.
## Inspiration
The fundamental architecture and window management techniques are heavily
inspired by [Yabai], another excellent MacOS window manager. Studying its
source code has provided invaluable insights into managing windows on MacOS,
particularly regarding undocumented functions.
The innovative concept of managing windows on a sliding strip is directly
inspired by [Niri] and [PaperWM.spoon].
## Installation
### Recommended System Options
- Like all non-native window managers for MacOS, Paneru requires accessibility
access to move windows. Once it runs you may get a dialog window asking for
permissions. Otherwise check the setting in System Settings under "Privacy &
Security -> Accessibility".
- Check your System Settings for "Displays have separate spaces" option. It
should be enabled - this allows Paneru to manage the workspaces independently.
- **Multiple displays**. Paneru is moving the windows off-screen, hiding them
to the left or right. If you have multiple displays, for example your laptop
open when docked to an external monitor you may experience weird behavior.
The issue is that when MacOS notices a window being moved too far off-screen
it will relocate it to a different display - which confuses Paneru! The
solution is to change the spatial arrangement of your additional display -
instead of having it to the left or right, move it above or below your main
display.
A [similar situation](https://nikitabobko.github.io/AeroSpace/guide#proper-monitor-arrangement)
exists with Aerospace window manager.
- **Off-screen window slivers**. Because macOS will forcibly relocate windows
that are moved fully off-screen, Paneru keeps a thin sliver of each
off-screen window visible at the screen edge. The `sliver_width` and
`sliver_height` options control the size of this sliver. This is a
workaround for a macOS limitation, not a design choice.
### Installing from Crates.io
Paneru is built using Rust's `cargo`. It can be installed directly from
`crates.io` or if you need the latest version, by fetching the source from Github.
```shell
$ cargo install paneru
```
### Installing from Github
```shell
$ git clone https://github.com/karinushka/paneru.git
$ cd paneru
$ cargo build --release
$ cargo install --path .
```
It can run directly from the command line or as a service.
Note, that you will need to grant acessibility priviledge to the binary.
### Installing with Nix
Add the paneru flake to your inputs.
```nix
# flake.nix
inputs.paneru = {
url = "github:karinushka/paneru";
inputs.nixpkgs.follows = "nixpkgs";
}
```
#### Home Manager
Paneru provides a home manager module to install and configure paneru.
> [!NOTE]
> You still need to enable accessibility permissions in the macOS settings
> the first time paneru is launched or any time it is updated.
```nix
# home.nix
{ inputs, ... }:
{
imports = [
inputs.paneru.homeModules.paneru
];
services.paneru = {
enable = true;
# Equivalent to what you would put into `~/.paneru` (See Configuration options below).
settings = {
options = {
preset_column_widths = [
0.25
0.33
0.5
0.66
0.75
];
swipe_gesture_fingers = 4;
animation_speed = 4000;
};
bindings = {
window_focus_west = "cmd - h";
window_focus_east = "cmd - l";
window_focus_north = "cmd - k";
window_focus_south = "cmd - j";
window_swap_west = "alt - h";
window_swap_east = "alt - l";
window_swap_first = "alt + shift - h";
window_swap_last = "alt + shift - l";
window_center = "alt - c";
window_resize = "alt - r";
window_fullwidth = "alt - f";
window_manage = "ctrl + alt - t";
window_stack = "alt - ]";
window_unstack = "alt + shift - ]";
quit = "ctrl + alt - q";
};
};
};
}
```
#### Standalone Package
Although we strongly recommend using home manager, the paneru flake also exposes a standalone package.
```nix
{ inputs, ... }:
{
# nix-darwin configuration (configuration.nix)
# system-wide
environment.systemPackages = [ inputs.paneru.packages.paneru ]
# or per-user
users.users."<name>".packages = [ inputs.paneru.packages.paneru ]
}
```
### Configuration
Paneru checks for configuration in following locations:
- `$HOME/.paneru`
- `$HOME/.paneru.toml`
- `$XDG_CONFIG_HOME/paneru/paneru.toml`
Additionally it allows overriding the location with `$PANERU_CONFIG` environment variable.
You can use the following example configuration as a starting point:
```
# syntax=toml
#
# Example configuration for Paneru.
#
[options]
# Enables focus follows mouse. Enabled by default, set to false to disable.
# focus_follows_mouse = true
# Enables mouse follows focus. Enabled by default, set to false to disable.
# mouse_follows_focus = true
# Array of widths used by the `window_resize` action to cycle between.
# Defaults to 25%, 33%, 50%, 66% and 75%.
preset_column_widths = [ 0.25, 0.33, 0.50, 0.66, 0.75 ]
# How many fingers to use for moving windows left and right.
# Make sure that it doesn't clash with OS setting for workspace switching.
# Values lower than 3 will be ignored.
# Remove the line to disable the gesture feature.
# Apple touchpads support gestures with more than five fingers (!),
# but it is probably not that useful to use two hands :)
swipe_gesture_fingers = 4
# Swiping keeps sliding windows until the first or last window.
# Set to false to clamp so edge windows stay on-screen. Enabled by default.
# continuous_swipe = true
# Animation speed in 1/10th of display resolution per second.
# E.g. a value of 20 means: move at a speed of two display sizes per second.
# To disable animations, leave this unset or set to a very large value.
animation_speed = 50
# Automatically center the focused window when switching focus with keyboard,
# i.e. 'window_focus_west' or 'window_focus_east'.
# auto_center = false
# Height of off-screen window slivers as a ratio (0.0–1.0) of the display
# height. Lower values hide the window's corner radius at screen edges.
# Default: 1.0 (full height, no inset).
# sliver_height = 1.0
# Width of off-screen window slivers in pixels. Controls how much of an
# off-screen window peeks from the screen edge.
# Default: 5 pixels.
# sliver_width = 5
# Padding applied at screen edges (in pixels). Independent from the
# between-window gaps set by per-window horizontal/vertical_padding.
# Default: 0 on all sides.
# padding_top = 0
# padding_bottom = 0
# padding_left = 0
# padding_right = 0
# When disabled, swiping of windows is clamped so you cannot scroll
# past the first or last window.
# When enabled (default) the strip slides freely, exposing the desktop behind.
# free_slide = true
[bindings]
# Moves the focus between windows. If there are no windows when moving up or
# down, will swtich focus to the display above or below.
window_focus_west = ["cmd - h", "cmd - leftarrow"]
window_focus_east = ["cmd - l", "cmd - rightarrow"]
window_focus_north = ["cmd - k", "cmd - uparrow"]
window_focus_south = ["cmd - j", "cmd - downarrow"]
# Swaps windows in chosen direction. If there are no windows to swap, will
# move the window to a display above or below.
window_swap_west = "alt - h"
window_swap_east = "alt - l"
window_swap_north = "alt - k"
window_swap_south = "alt - j"
# Jump to the left-most or right-most windows.
window_focus_first = "cmd + shift - h"
window_focus_last = "cmd + shift - l"
# Move the current window into the left-most or right-most positions.
window_swap_first = "alt + shift - h"
window_swap_last = "alt + shift - l"
# Centers the current window on screen.
window_center = "alt - c"
# Cycles between the window sizes defined in the `preset_column_widths` option.
window_resize = "alt - r"
# Toggle full width for the current focused window.
window_fullwidth = "alt - f"
# Toggles the window for management. If unmanaged, the window will be "floating".
window_manage = "ctrl + alt - t"
# Stacks and unstacks a window into the left column. Each window gets a 1/N of the height.
window_stack = "alt - ]"
window_unstack = "alt + shift - ]"
# Moves currently focused window to the next display.
window_nextdisplay = "alt + shift - n"
# Moves the mouse pointer to the next display.
mouse_nextdisplay = "alt - n"
# Size stacked windows in the column to equal heights.
window_equalize = "alt + shift - e"
# Quits the window manager.
quit = "ctrl + alt - q"
# Window properties, matched by a RegExp title string.
[windows]
[windows.pip]
# Title RegExp pattern is required.
title = "Picture.*(in)?.*[Pp]icture"
# Do not manage this window, e.g. it will be floating.
floating = true
[windows.neovide]
# Matches an editor and always inserts its window at index 1.
title = ".*"
bundle_id = "com.neovide.neovide"
index = 1
[windows.popup]
# Matches a popup and silently appends it at the end.
title = "Unimportant popup window"
dont_focus = true
index = 100
[windows.neovide_width]
# Sets a specific initial width for a window (as a ratio of display width).
title = ".*"
bundle_id = "com.neovide.neovide"
width = 0.5
[windows.passwords]
# Floating window placed on a grid. The format is "cols:rows:x:y:w:h".
# This divides the display into a 6x6 grid and places the window at cell (1,1)
# spanning 4 columns and 4 rows — roughly centered covering 2/3 of the display.
title = "Passwords.*"
floating = true
grid = "6:6:1:1:4:4"
[windows.all]
# Matches all windows and adds a few pixels of spacing to their borders.
# Note: horizontal_padding and vertical_padding create gaps on all sides of
# each window. At screen edges, the gap is cancelled out so padding only
# appears between windows. Use the [options] padding_* settings above to
# control screen edge margins independently.
title = ".*"
horizontal_padding = 4
vertical_padding = 2
```
Paste this into your terminal to create a default configuration file:
```
$ cat > ~/.paneru <<EOF
# ... paste the above configuration here ...
EOF
```
**Live Reloading:** Configuration changes made to your `~/.paneru` file are
automatically reloaded while Paneru is running. This is extremely useful for
tweaking keyboard bindings and other settings without restarting the
application. The settings can be changed while Paneru is running - they will
be automatically reloaded.
### Running as a service
```shell
$ paneru install
$ paneru start
```
### Running in the foreground
```shell
$ paneru
```
### Sending Commands
Paneru exposes a `send-cmd` subcommand that lets you control the running
instance from the command line via a Unix socket (`/tmp/paneru.socket`). Any
command that can be bound to a hotkey can also be sent programmatically:
```shell
$ paneru send-cmd <command> [args...]
```
#### Available commands
| `window focus <direction>` | Move focus to a window in the given direction |
| `window swap <direction>` | Swap the focused window with a neighbour |
| `window center` | Center the focused window on screen |
| `window resize` | Cycle through `preset_column_widths` |
| `window fullwidth` | Toggle full-width mode for the focused window |
| `window manage` | Toggle managed/floating state |
| `window equalize` | Distribute equal heights in the focused stack |
| `window stack` | Stack the focused window onto its left neighbour |
| `window unstack` | Unstack the focused window into its own column |
| `window nextdisplay` | Move the focused window to the next display |
| `mouse nextdisplay` | Warp the mouse pointer to the next display |
| `printstate` | Print the internal ECS state to the debug log |
| `quit` | Quit Paneru |
Where `<direction>` is one of: `west`, `east`, `north`, `south`, `first`, `last`.
#### Examples
```shell
# Move focus one window to the right.
$ paneru send-cmd window focus east
# Swap the current window to the left.
$ paneru send-cmd window swap west
# Center and resize in one shot (two separate calls).
$ paneru send-cmd window center && paneru send-cmd window resize
# Jump to the left-most window.
$ paneru send-cmd window focus first
```
#### Scripting ideas
Because `send-cmd` works over a Unix socket, you can drive Paneru from shell
scripts, `cron` jobs, or other automation tools:
- **Launch-and-arrange workflow.** Open an application and immediately position
it: `open -a Safari && sleep 0.5 && paneru send-cmd window resize`.
- **One-key layout reset.** Bind a script that focuses the first window, resizes
it, then moves east and resizes the next one — recreating a preferred layout
after windows get shuffled.
- **Integration with other tools.** Pipe focus events from tools like
[Hammerspoon](https://www.hammerspoon.org) or
[skhd](https://github.com/koekeishiya/skhd) into `paneru send-cmd` for
compound actions that go beyond a single hotkey.
- **Multi-display orchestration.** Move a window to the next display and
immediately warp the mouse there:
```shell
paneru send-cmd window nextdisplay && paneru send-cmd mouse nextdisplay
```
## Future Enhancements
- More commands for manipulating windows: fullscreen, finegrained size adjustments, etc.
- Scriptability. A nice feature would be to use Lua for configuration and simple scripting,
like triggering and positioning specific windows or applications.
## Communication
There is a public Matrix room [`#paneru:matrix.org`](https://matrix.to/#/%23paneru%3Amatrix.org). Join and ask any questions.
## Architecture Overview
Paneru's architecture is built around the **Bevy ECS (Entity Component System)**, which manages the window manager's state as a collection of entities (displays, workspaces, applications, and windows) and components.
The system is decoupled into three primary layers:
1. **Platform Layer (`src/platform/`)**: Directly interfaces with macOS via `objc2` and Core Graphics. It runs the native Cocoa event loop and pumps OS events into a channel consumed by Bevy.
2. **Management Layer (`src/manager/`)**: Defines OS-agnostic traits (`WindowManagerApi`, `WindowApi`) that abstract window manipulation. The macOS-specific implementations (`WindowManagerOS`, `WindowOS`) bridge these traits to the Accessibility and SkyLight APIs.
3. **ECS Layer (`src/ecs/`)**: The "brain" of the application. Bevy systems process incoming events, handle input triggers, and manage animations.
### Repository Structure
- **`main` branch**: Contains the stable, released code.
- **`testing` branch**: Used for experimental features and architectural refactors. This branch is volatile and may be force-pushed.
## Tile Scrollably Elsewhere
Here are some other projects which implement a similar workflow:
- [Niri]: a scrollable tiling Wayland compositor.
- [PaperWM]: scrollable tiling on top of GNOME Shell.
- [karousel]: scrollable tiling on top of KDE.
- [papersway]: scrollable tiling on top of sway/i3.
- [hyprscroller] and [hyprslidr]: scrollable tiling on top of Hyprland.
- [PaperWM.spoon]: scrollable tiling on top of MacOS.
[Yabai]: https://github.com/koekeishiya/yabai
[Niri]: https://github.com/YaLTeR/niri
[PaperWM]: https://github.com/paperwm/PaperWM
[karousel]: https://github.com/peterfajdiga/karousel
[papersway]: https://spwhitton.name/tech/code/papersway/
[hyprscroller]: https://github.com/dawsers/hyprscroller
[hyprslidr]: https://gitlab.com/magus/hyprslidr
[PaperWM.spoon]: https://github.com/mogenson/PaperWM.spoon