diff --git a/.gitignore b/.gitignore
new file mode 100644
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--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,7 @@
+# Advent of Code
+/session
+/inputs/*
+!/inputs/test/
+
+# JetBrains
+.idea/
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..b596c47
--- /dev/null
+++ b/README.md
@@ -0,0 +1,8 @@
+# Advent of Code 2023
+
+Solutions for Advent of Code 2023 in Ruby
+
+https://adventofcode.com/2023
+
+### Instructions
+Put the value of your adventofcode.com `session` cookie in a file called `session` to automatically download input files 
diff --git a/days/day00.rb b/days/day00.rb
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index 0000000..19e5348
--- /dev/null
+++ b/days/day00.rb
@@ -0,0 +1,19 @@
+require_relative '../lib/aoc'
+
+module Day00
+	extend AOC::Day
+
+	@num = 0
+	@ans_test1 = -1
+	@ans_test2 = -1
+
+	def self.solve_part1(input)
+		return 0
+	end
+
+	def self.solve_part2(input)
+		return 0
+	end
+end
+
+Day00.run
diff --git a/lib/aoc.rb b/lib/aoc.rb
new file mode 100644
index 0000000..632ddc0
--- /dev/null
+++ b/lib/aoc.rb
@@ -0,0 +1,117 @@
+require 'open-uri'
+
+module AOC
+
+	YEAR = 2023
+
+	module Day
+		# Settings
+		attr_accessor :num, :ans_test1, :ans_test2
+
+		# Instance variables
+		attr_accessor :input, :test_input, :test_input1, :test_input2
+
+		def run
+			attr_defaults
+			puts "--- Running day #{@num} ---".yellow
+
+			load_inputs
+
+			if @input.nil?
+				puts "Input is missing".red
+				return
+			end
+
+			run_part 1
+			run_part 2
+		end
+
+		def load_inputs
+			# Load inputs
+			if @input.nil?
+				# Load actual input of this day
+				path = "inputs/input%02d" % @num
+				unless File.exist?(path)
+					return unless AOC::Net.configured? and @num != 0
+					AOC::Net.retrieve_input @num
+				end
+				@input = File.read(path)
+			end
+			if @test_input.nil? and not (@ans_test1.nil? and @ans_test2.nil?)
+				# TODO: Allow part 1 and 2 to have different inputs
+				# Load test input of this day
+				path = "inputs/test/test_input%02d" % @num
+				if File.exist?(path)
+					@test_input = File.read(path)
+				end
+			end
+		end
+
+		def run_part(part)
+			puts "--- Part #{part} ---".yellow
+
+			# Check if the solve_partX method is implemented
+			unless self.respond_to?("solve_part#{part}")
+				puts "This part has not been implemented".red
+				return
+			end
+
+			# Run test if configured
+			ans_test = self.send("ans_test#{part}")
+			if not ans_test.nil? and not @test_input.nil?
+				test = self.send("solve_part#{part}", @test_input)
+
+				if test != ans_test
+					puts "Test failed, result '#{test}', expected '#{ans_test}'".red
+					return
+				end
+
+				puts "Test successful".green
+			end
+
+			# Solve this part
+			result = self.send("solve_part#{part}", @input)
+			puts "Result: #{result}"
+		end
+
+		def attr_defaults
+			@num = 0 if @num.nil?
+		end
+	end
+
+	module Net
+		@base_url = "https://adventofcode.com"
+
+		def self.configured?
+			if @session.nil? and File.exist?("session")
+				@session = File.read("session")
+			end
+			return !@session.nil?
+		end
+
+		def self.retrieve_input(day)
+			return unless configured?
+
+			puts "Downloading input file..."
+
+			local_path = "inputs/input%02d" % day
+
+			url = "#{@base_url}/#{AOC::YEAR}/day/#{day}/input"
+			headers = [
+				"User-Agent" => "https://github.com/Aeilko/Advent-of-Code-#{@year}",
+				"Cookie" => "session=#{@session}",
+			]
+
+			content = URI.open(url, *headers).read
+			File.write(local_path, content, mode: "w")
+
+			content
+		end
+	end
+end
+
+class String
+	def red;	"\e[31m#{self}\e[0m" end
+	def green;	"\e[32m#{self}\e[0m" end
+	def yellow;	"\e[33;1m#{self}\e[0m" end
+end