Gets a random wallpaper from wallhaven.cc website and sets it as the current gnome background.

wallhaven.sh

#!/bin/bash

# set variables
api_key="" # put your api key here
purity="110" # SFW, Sketchy, NSFW
sorting="toplist" # date_added relevance random views favorites toplist automaticlly 
topRange="3d" # 1d 3d 1w 1M 3M 6M 1y
ratios="landscape" # landscape portrait 16x9 16x10 21x9 32x9 ...
categories="111" # General, Anime, People
query="" # Search for ... - 
page=$((random_number % 5 + 1)) # Get wallpaper from first `n` pages (default: 5)

api_url="https://wallhaven.cc/api/v1/search?apikey=${api_key}&q=&categories=${categories}&purity=${purity}&sorting=${sorting}&topRange=${topRange}&ratios=${ratios}&atleast=1920x1080&page=${page}"
if [ -n "$query" ]; then
    api_url="$api_url&q=$query"
fi

# make request to Wallhaven API and get a random wallpaper
json=$(curl -s $api_url)

# parse the JSON response to get a random wallpaper URL
url=$(echo $json | jq -r '.data[].path' | shuf -n 1)

# get the filename from the URL
filename=$(basename "$url")

# prints the choosen background and sends a notification
echo $filename
notify-send wallhaven $filename  -i backgroundtool

dir='$HOME/Pictures'
if [ -f "$dir/$filename" ]; then
    echo "File exists"
else
    # download the wallpaper to the same directory as the script with its original filename
    curl -s "$url" >"$dir/$filename"
fi

if [ -f "$dir/$filename" ]; then
    # set the wallpaper as the current background in gnome
    gsettings set org.gnome.desktop.background picture-uri "file://$dir/$filename"
    gsettings set org.gnome.desktop.background picture-uri-dark "file://$dir/$filename"
fi

I coded it for personal use but it might help someone :)

Thank you