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# randpaper - A high-performance wallpaper & theme daemon for Wayland
`randpaper` is a lightweight Rust utility designed for efficiency. It manages
per-monitor wallpaper rotation and optional system-wide theme
synchronization—replacing complex script chains with a single, optimized binary.
# 🚀 Features
- ⚡ **Performance**: Written in Rust using `tokio`. Scans your image directory
once into memory (caching paths) to prevent disk I/O spikes, even with massive
wallpaper collections.
- 🎨 **Dynamic Theming**: Automatically extracts dominant colors from the
current wallpaper and generates config files for **Ghostty**, **Kitty**, and
**Foot**, keeping your terminal in sync with your desktop.
- **Waybar Theming**: Generates CSS variables based on the image palette.
and reloads Waybar when it changes wallpapers applying the theming
automatically.
- 🖥️ **Multi-Monitor**: Assigns a unique random image to every active output
simultaneously.
- 🔄 **Dual Operating Modes**: Run as a background daemon with automatic
cycling, or use one-shot mode for manual wallpaper changes.
- 🛠️ **Modular Backends**: Works seamlessly with **Sway** and **Hyprland** (via
Sway IPC or `hyprctl`) and supports both `swaybg` and `swww` renderers.
- Support for both `swww` and its replacement `awww`.
---
## 🛠 Installation
**Prerequisites**
You need `swaybg` or (`swww` / `awww`) installed as the renderer.
```bash
# From source
cargo install --git https://github.com/saylesss88/randpaper
# crates.io
cargo install randpaper
```
<details>
<summary> ✔️ Nix </summary>
Add as a flake input:
```nix
inputs = {
randpaper.url = "github:saylesss88/randpaper";
};
```
Install in `environment.systemPackages` or `home.packages`:
```nix
environment.systemPackages = {
inputs.randpaper.packages.${pkgs.stdenv.hostPlatform.system}.default
};
```
- Pass `inputs` through `specialArgs` in your `flake.nix`
And add an `exec` for either hyprland or sway, only for `randpaper`:
Hyprland Example:
```nix
wayland.windowManager.hyprland = {
settings = {
exec-once = [
# Standard Usage
"randpaper --time 15m /home/your-user/Pictures/wallpapers --backend hyprland --renderer swww"
# UWSM Usage w/ swaybg
"uwsm app -- randpaper --time 15m /home/your-user/Pictures/wallpapers --backend hyprland --renderer swaybg"
];
};
}
```
Sway Example:
```nix
wayland.windowManager.sway = {
extraConfig = ''
# Default backend is Sway
exec randpaper --time 30m /home/your-user/wallpapers
'';
};
```
> Note: `randpaper` manages the renderer process for you. You do not need
> separate `exec-once = swaybg ...` or `exec-once = swww ...` lines in your
> config.
</details>
---
## 🧾 Usage
**Daemon Mode (Background Process)**
With `swww` or `awww` installed you can test which mode you want from the
command line before adding an `exec-once` for `randpaper` to your configuration:
When you provide the `--time` flag, `randpaper` runs as a daemon and
automatically cycles wallpapers at the specified interval:
```bash
# Change every 5 minutes using Hyprland + swww transitions
randpaper --time 5m --backend hyprland --renderer swww ~/Pictures/wallpapers
# Change every hour with custom transitions
randpaper --time 1h --renderer swww --transition-type fade ~/Pictures/wallpapers
```
- These commands work without `swww-daemon` running because `randpaper`
automatically launches a `swww-daemon` process if one isn't already running.
**One-Shot Mode (Pick Once & Exit)**
Without the `--time` flag, `randpaper` picks a random wallpaper, updates themes,
and exits immediately.
It's recommended to run one-shot via a compositor keybind so it inherits the
correct session/IPC environment.(i.e., running
`randpaper ~/Pictures/wallpapers`from the command line doesn't work as expected)
```conf
# Sway: cycle wallpaper + themes now (one-shot)
bindsym $mod+Shift+n exec randpaper ~/Pictures/wallpapers
```
```conf
# Hyprland: cycle wallpaper + themes (one-shot)
"$mod SHIFT,N,exec, randpaper --backend hyprland /home/jr/Pictures/wallpapers2"
```
- `swaybg` can't be one-shot from the command line because it's not a
set-and-exit command; it's a long-running wallpaper service.
**Use cases for one-shot mode**:
- Manual wallpaper changes via keybinds
- Scripted theme updates
- Testing without running a daemon
**swww/awww Transitions**:
```bash
# Use fade transitions
randpaper --renderer swww --transition-type fade --transition-step 90 --transition-fps 60 ~/Pictures/wallpapers
# Use wipe transitions for hyprland
randpaper --renderer swww --transition-type wipe --transition-step 90 --transition-fps 60 ~/Pictures/wallpapers --backend hyprland
```
- Again, the above commands only work if there isn't already a `swww-daemon`
instance running. Adding an `exec randpaper` to your config automatically adds
an `exec swww-daemon`
- [Sample wallpaper repo](https://github.com/saylesss88/wallpapers2)
**Advanced Options**
| `[DIR]` | Directory containing images | `.` |
| `-t, --time` | Time between changes(e.g., 15m, 1h) | `30m` |
| `-b, --backend` | Detection backend: `sway` or `hyprland` | `sway` |
| `-o, --outputs` | Specific outputs to target (Sway only) | Auto-discover |
| `-r, --renderer` | Renderer tool: `swaybg` or `swww` | `swaybg` |
| `--transition-type` | swww transition: `fade`, `wipe`, `outer` | `simple` |
| `-s, --transition-step` | swww transition step (0-100) | `90` |
| `-f, --transition-fps` | swww target frame rate for transitions | `30` |
- `--transition-type`: Choose between (`simple`, `fade`, `wipe`, `outer`,
`inner`, `random`)
> NOTE: All transition options are ignored when using `--renderer swaybg`.
---
## 🎨 Automatic Terminal Theming
`randpaper` automatically extracts a 16-color palette from your wallpaper and
generates theme files in `~/.config/randpaper/themes/`.
To use them, add the include line to your terminal config:
**Ghostty**
File: `~/.config/ghostty/config`
```text
config-file = ~/.config/randpaper/themes/ghostty.config
```
**Foot**
File: `~/.config/foot/foot.ini` (Place near end of file)
```text
[main]
include=~/.config/randpaper/themes/foot.ini
```
**Kitty**
File: `~/.config/kitty/kitty.conf`
```text
include ~/.config/randpaper/themes/kitty.conf
```
**Live-Reload of Terminal Themes**
- **Ghostty**: live reload works with either "cycle" keybind (i.e., theme
updates immediately with either `pkill -USR1 randpaper` from either a keybind
or the command line or a keybind set to
`exec randpaper ~/Pictures/wallpapers`)(Tested on Fedora with Sway, expect
different behavior on NixOS)
- **Foot / Kitty**: the theme file is updated, but existing windows may not
live-reload reliably; close and reopen the terminal to pick up the new theme.
(Work in Progress)
<details>
<summary> ✔️**GhosTTY on NixOS dynamic theming** </summary>
```nix
# home.nix or ghostty.nix
programs.ghostty = {
enable = true;
settings = {
# The '?' makes the include optional/non-blocking
"config-file" = "?~/.config/randpaper/themes/ghostty.config";
};
};
```
- On boot up, the generated theme will be applied.
- Run the cycle command then type `pkill -USR2 ghostty` to apply the theme
instantly.
</details>
---
## Waybar Dynamic Theming (Optional)
<details>
<summary> ✔️ Waybar Dynamic Theming </summary>
To use `randpaper` with a `waybar` setup, ensure you call the daemon via
`exec waybar` in your Sway or Hyprland config.
(Sway Example `~/.config/sway/config`):
```config
exec randpaper --time 10m ~/Pictures/wallpapers
bar {
swaybar_command waybar
}
# ---snip---
```
`randpaper` automatically generates a Waybar CSS color file from the current
wallpaper palette and writes it to:
- `~/.config/randpaper/themes/waybar.css`
This file only defines color variables (it doesn't change your bar by itself).
To use it, you import it from your Waybar `style.css` and then reference the
variables in your existing rules.
Example of the generated `waybar.css` file:
```css
/* auto-generated by randpaper */
@define-color rp_bg #1c1c24;
@define-color rp_fg #e4dcd4;
@define-color rp_accent #f394a4;
@define-color rp_warn #201c24;
@define-color rp_ok #201c24;
@define-color rp_border #f394a4;
@define-color rp_muted #1c1c24;
```
1. Import the generated file
At the very top of your Waybar `style.css` (Change `YOUR_USER` to your
username):
```css
@import "/home/YOUR_USER/.config/randpaper/themes/waybar.css";
```
2. Use the variables in your CSS
Replace hard-coded colors with variables like `@rp_bg`, `@rp_fg`, `@rp_accent`,
etc.
Example:
```css
window#waybar {
background-color: alpha(@rp_bg, 0.8);
color: @rp_fg;
}
#workspaces button.focused {
background-color: @rp_accent;
color: @rp_bg;
}
```
- [Full `style.css` Example](https://github.com/saylesss88/.dotfiles/blob/main/waybar/.config/waybar/style.css)
3. `randpaper` automatically reloads Waybar when it changes wallpapers, keeping
your bar perfectly themed without manual intervention. (`SIGUSR2`
zero-flicker reload)
Obviously, the more hard-coded colors you replace with the dynamically generated
CSS variables the more noticeable it will be.
> NOTE: Just adding the `@import` at the top makes the variables available, you
> need to reference them for the changes to be applied.
- [NixOS Waybar Example](https://github.com/saylesss88/flake/blob/main/home/hypr/waybar.nix)
- On NixOS, after cycling with one-shot run `pkill -USR2 waybar` to apply the
new theme.
</details>
---
## ⏭️ Cycling Wallpapers & Themes
### Manual Wallpaper Change (Recommended)
The simplest way to instantly change wallpapers is to run one-shot mode while
the randpaper daemon is running:
**Hyprland Config**:
```text
bind = $mainMod SHIFT, N, exec, randpaper ~/Pictures/wallpapers --backend hyprland
```
**Sway Config**:
```text
bindsym $mod+Shift+n exec randpaper ~/Pictures/wallpapers
```
This picks a new wallpaper, updates all themes (terminal + Waybar), and exits.
Your background daemon continues running for automatic cycles.
---
### Signal Running Daemon (Alternative for Standare Filesystem Hierarchy layouts)
You can also force the daemon to cycle immediately without spawning a separate
process:
**Sway Config**:
```text
bindsym $mod+n exec pkill -USR1 randpaper
```
**Hyprland Config**:
```text
bind = $mainMod SHIFT, N, exec, pkill -USR1 randpaper
```
**Shell**:
```bash
pkill -USR1 randpaper
```
Now when you run the above keybind, you will get a new wallpaper, terminal
theme, and waybar theme.
> NOTE: Expect different behavior on NixOS.
---
## ⚙️ How it Works
1. **Startup**: Caches all valid image paths (`jpg`, `png`, `bmp`, `webp`) from
the target directory into memory.
2 **Loop**(daemon mode): Every interval (e.g., 30m):
- Queries active monitors via IPC.
- Picks a random image for the primary monitor and extracts its color palette.
- Generates theme files and triggers terminal reloads.
- Spawns a non-blocking background process (`swaybg` daemon or `swww` client) to
update the display.
- Sleeps efficiently until the next cycle.
3. One-Shot (no `--time`): Picks wallpaper, updates themes, exits immediately.
- Works reliably as a keybind, may have to close out terminal and relaunch for
the new theme to be applied.
---
## License
- [Apache License 2.0](https://github.com/saylesss88/randpaper/blob/main/LICENSE)