diff --git a/2023/aoc2023.cabal b/2023/aoc2023.cabal
new file mode 100644
index 0000000..1748b5a
--- /dev/null
+++ b/2023/aoc2023.cabal
@@ -0,0 +1,126 @@
+cabal-version:      3.0
+-- The cabal-version field refers to the version of the .cabal specification,
+-- and can be different from the cabal-install (the tool) version and the
+-- Cabal (the library) version you are using. As such, the Cabal (the library)
+-- version used must be equal or greater than the version stated in this field.
+-- Starting from the specification version 2.2, the cabal-version field must be
+-- the first thing in the cabal file.
+
+-- Initial package description 'aoc2023' generated by
+-- 'cabal init'. For further documentation, see:
+--   http://haskell.org/cabal/users-guide/
+--
+-- The name of the package.
+name:               aoc2023
+
+-- The package version.
+-- See the Haskell package versioning policy (PVP) for standards
+-- guiding when and how versions should be incremented.
+-- https://pvp.haskell.org
+-- PVP summary:     +-+------- breaking API changes
+--                  | | +----- non-breaking API additions
+--                  | | | +--- code changes with no API change
+version:            0.1.0.0
+
+-- A short (one-line) description of the package.
+-- synopsis:
+
+-- A longer description of the package.
+-- description:
+
+-- The license under which the package is released.
+-- license:
+
+-- The file containing the license text.
+-- license-file:
+
+-- The package author(s).
+author:             C4 Patino
+
+-- An email address to which users can send suggestions, bug reports, and patches.
+maintainer:         c4patino@gmail.com
+
+-- A copyright notice.
+-- copyright:
+
+build-type:         Simple
+
+-- Extra doc files to be distributed with the package, such as a CHANGELOG or a README.
+-- extra-doc-files:    
+
+-- Extra source files to be distributed with the package, such as examples, or a tutorial module.
+-- extra-source-files:
+
+common warnings
+    ghc-options: -Wall
+
+library
+    -- Import common warning flags.
+    import:           warnings
+
+    -- Modules exported by the library.
+    exposed-modules:  Day01, Day02
+
+    -- Modules included in this library but not exported.
+    -- other-modules:
+
+    -- LANGUAGE extensions used by modules in this package.
+    -- other-extensions:
+
+    -- Other library packages from which modules are imported.
+    build-depends:    base ^>=4.19.2.0
+
+    -- Directories containing source files.
+    hs-source-dirs:   src
+
+    -- Base language which the package is written in.
+    default-language: Haskell2010
+
+executable aoc2023
+    -- Import common warning flags.
+    import:           warnings
+
+    -- .hs or .lhs file containing the Main module.
+    main-is:          Main.hs
+
+    -- Modules included in this executable, other than Main.
+    -- other-modules:
+
+    -- LANGUAGE extensions used by modules in this package.
+    -- other-extensions:
+
+    -- Other library packages from which modules are imported.
+    build-depends:
+        base ^>=4.19.2.0,
+        aoc2023
+
+    -- Directories containing source files.
+    hs-source-dirs:   app
+
+    -- Base language which the package is written in.
+    default-language: Haskell2010
+
+test-suite aoc2023-test
+    -- Import common warning flags.
+    import:           warnings
+
+    -- Base language which the package is written in.
+    default-language: Haskell2010
+
+    -- Modules included in this executable, other than Main.
+    other-modules:	  Common.Tests, Day01Spec, Day02Spec
+
+    -- LANGUAGE extensions used by modules in this package.
+    -- other-extensions:
+
+    -- The interface type and version of the test suite.
+    type:             exitcode-stdio-1.0
+
+    -- Directories containing source files.
+    hs-source-dirs:   test
+
+    -- The entrypoint to the test suite.
+    main-is:          Spec.hs
+
+    -- Test dependencies.
+    build-depends: base ^>=4.19.2.0, hspec, hspec-contrib, QuickCheck, HUnit, aoc2023
diff --git a/2023/app/Main.hs b/2023/app/Main.hs
new file mode 100644
index 0000000..369f1cf
--- /dev/null
+++ b/2023/app/Main.hs
@@ -0,0 +1,60 @@
+module Main where
+
+import qualified Day01
+import qualified Day02
+import System.Console.GetOpt
+import System.Environment (getArgs)
+import System.Exit (exitFailure)
+
+data Options = Options {optFile :: Maybe FilePath, optHelp :: Bool} deriving (Show)
+
+defaultOptions :: Options
+defaultOptions = Options {optFile = Nothing, optHelp = False}
+
+options :: [OptDescr (Options -> Options)]
+options =
+  [ Option
+      ['f']
+      ["file"]
+      (ReqArg (\f opts -> opts {optFile = Just f}) "FILE")
+      "input file to use",
+    Option
+      ['h']
+      ["help"]
+      (NoArg (\opts -> opts {optHelp = True}))
+      "show help"
+  ]
+
+runDay :: Int -> FilePath -> IO (String, String)
+runDay 1 filename = do
+  (a, b) <- Day01.run filename
+  return (show a, show b)
+runDay 2 filename = do
+  (a, b) <- Day02.run filename
+  return (show a, show b)
+runDay _ _ = return ("Not implemented", "Not implemented")
+
+defaultFilename :: Int -> FilePath
+defaultFilename day = "inputs/day" ++ (if day < 10 then "0" else "") ++ show day ++ "/input.txt"
+
+main :: IO ()
+main = do
+  args <- getArgs
+  case getOpt Permute options args of
+    (opts, [dayStr], []) -> do
+      let day = read dayStr
+          finalOpts = foldl (flip id) defaultOptions opts
+          filename = case optFile finalOpts of
+            Just f -> f
+            Nothing -> defaultFilename day
+      (part1Answer, part2Answer) <- runDay day filename
+      putStrLn $ "Part 1: " ++ part1Answer
+      putStrLn $ "Part 2: " ++ part2Answer
+    (_, [], []) -> do
+      putStrLn "Error: Day number is required"
+      putStrLn $ usageInfo "Usage: aoc2023 <day> [OPTIONS]" options
+      exitFailure
+    (_, _, errs) -> do
+      putStrLn $ concat errs
+      putStrLn $ usageInfo "Usage: aoc2023 <day> [OPTIONS]" options
+      exitFailure
diff --git a/2023/inputs/day01/part1.txt b/2023/inputs/day01/part1.txt
new file mode 100644
index 0000000..7bbc69a
--- /dev/null
+++ b/2023/inputs/day01/part1.txt
@@ -0,0 +1,4 @@
+1abc2
+pqr3stu8vwx
+a1b2c3d4e5f
+treb7uchet
diff --git a/2023/inputs/day01/part2.txt b/2023/inputs/day01/part2.txt
new file mode 100644
index 0000000..41aa89c
--- /dev/null
+++ b/2023/inputs/day01/part2.txt
@@ -0,0 +1,7 @@
+two1nine
+eightwothree
+abcone2threexyz
+xtwone3four
+4nineeightseven2
+zoneight234
+7pqrstsixteen
diff --git a/2023/inputs/day02/example.txt b/2023/inputs/day02/example.txt
new file mode 100644
index 0000000..295c36d
--- /dev/null
+++ b/2023/inputs/day02/example.txt
@@ -0,0 +1,5 @@
+Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
+Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue
+Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red
+Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red
+Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green
diff --git a/2023/src/Day01.hs b/2023/src/Day01.hs
new file mode 100644
index 0000000..04fbcfd
--- /dev/null
+++ b/2023/src/Day01.hs
@@ -0,0 +1,42 @@
+module Day01 (part1, part2, run) where
+
+import Data.Char (isDigit)
+import Data.List (isPrefixOf)
+import Data.Maybe (maybeToList)
+
+part1 :: [String] -> Int
+part1 = sum . map (extractValue . filter isDigit)
+
+part2 :: [String] -> Int
+part2 = sum . map (extractValue . collectDigits)
+
+run :: FilePath -> IO (Int, Int)
+run filename =
+  readFile filename >>= \contents ->
+    let parsed = lines contents
+     in return (part1 parsed, part2 parsed)
+
+collectDigits :: String -> String
+collectDigits [] = []
+collectDigits s@(c : cs)
+  | isDigit c = c : collectDigits cs
+  | otherwise = maybeToList (spelledDigitToChar s) ++ collectDigits cs
+
+extractValue :: String -> Int
+extractValue [] = 0
+extractValue s@(d : _) = read [d, last s]
+
+spelledDigitToChar :: String -> Maybe Char
+spelledDigitToChar s = lookup True matches
+  where
+    matches =
+      [ ("one" `isPrefixOf` s, '1'),
+        ("two" `isPrefixOf` s, '2'),
+        ("three" `isPrefixOf` s, '3'),
+        ("four" `isPrefixOf` s, '4'),
+        ("five" `isPrefixOf` s, '5'),
+        ("six" `isPrefixOf` s, '6'),
+        ("seven" `isPrefixOf` s, '7'),
+        ("eight" `isPrefixOf` s, '8'),
+        ("nine" `isPrefixOf` s, '9')
+      ]
diff --git a/2023/src/Day02.hs b/2023/src/Day02.hs
new file mode 100644
index 0000000..3514dbf
--- /dev/null
+++ b/2023/src/Day02.hs
@@ -0,0 +1,76 @@
+module Day02 (part1, part2, run) where
+
+import Text.Read (readMaybe)
+
+data Game = Game {id :: Int, draw :: Draw} deriving (Show)
+
+data Draw = Draw {red :: Int, green :: Int, blue :: Int} deriving (Show)
+
+part1 :: [Game] -> Int
+part1 = sum . map gid . filter possible
+  where
+    gid (Game i _) = i
+
+part2 :: [Game] -> Int
+part2 = sum . map power
+  where
+    power (Game _ (Draw r g b)) = r * g * b
+
+run :: FilePath -> IO (Int, Int)
+run filename = do
+  input <- readFile filename
+  let games = parseGames input
+  return (part1 games, part2 games)
+
+instance Semigroup Draw where
+  (Draw a b c) <> (Draw x y z) = Draw (max a x) (max b y) (max c z)
+
+instance Monoid Draw where
+  mempty = Draw 0 0 0
+
+possible :: Game -> Bool
+possible = valid . draw
+  where
+    valid (Draw r g b) = r <= 12 && g <= 13 && b <= 14
+
+parseGames :: String -> [Game]
+parseGames input = map parseGame $ lines input
+
+parseGame :: String -> Game
+parseGame s =
+  let (header, rest) = break (== ':') s
+      gameId = read (drop 5 header) :: Int
+      drawsStr = drop 2 rest
+      draws = parseDraws drawsStr
+   in Game gameId draws
+
+parseDraws :: String -> Draw
+parseDraws s =
+  let drawParts = splitOn ';' s
+   in foldl (<>) mempty (map parseDraw drawParts)
+
+parseDraw :: String -> Draw
+parseDraw s =
+  let counts = splitOn ',' s
+   in foldl (<>) mempty (map parseCount counts)
+
+parseCount :: String -> Draw
+parseCount s =
+  case words s of
+    [nStr, color] ->
+      case (readMaybe nStr :: Maybe Int) of
+        Just i -> case color of
+          "red" -> Draw i 0 0
+          "green" -> Draw 0 i 0
+          "blue" -> Draw 0 0 i
+          _ -> mempty
+        Nothing -> mempty
+    _ -> mempty
+
+splitOn :: Char -> String -> [String]
+splitOn _ [] = []
+splitOn delim str =
+  let (first, rest) = break (== delim) str
+   in first : case rest of
+        [] -> []
+        (_ : rest') -> splitOn delim rest'
diff --git a/2023/test/Common/Tests.hs b/2023/test/Common/Tests.hs
new file mode 100644
index 0000000..1793bbe
--- /dev/null
+++ b/2023/test/Common/Tests.hs
@@ -0,0 +1,44 @@
+module Common.Tests where
+
+import Test.Hspec
+
+-- | Represents a single test case with an input file and its expected output.
+data TestCase a = TestCase
+  { -- | Path to the input file for the test case.
+    filename :: FilePath,
+    -- | Expected output value for the test case, of any type 'a'.
+    expectedOutput :: a
+  }
+
+-- | Run a suite of test cases by applying a runner function to input files,
+--   then projecting a part of the result for comparison against expected outputs.
+--
+-- Parameters:
+--
+-- * @label@: parent label for the specification.
+-- * @projector@: function to extract a single value from a tuple (e.g., part 1 or part 2).
+-- * @runner@: function under test, which takes a filename and returns an IO action producing a tuple of outputs.
+-- * @testCases@: list of test cases with input files and expected results.
+--
+-- Returns an Hspec 'Spec' running all test cases with descriptive labels and assertions.
+mkPartSpec ::
+  (Eq a, Show a) =>
+  -- | parent label for the specification
+  String ->
+  -- | projector from a tuple to the value to test
+  ((a, a) -> a) ->
+  -- | function under test (runner)
+  (FilePath -> IO (a, a)) ->
+  -- | list of test cases with input files and expected outputs
+  [TestCase a] ->
+  -- | resulting Hspec Spec with all tests
+  Spec
+mkPartSpec label projector runner testCases =
+  describe label $
+    mapM_
+      ( \(TestCase file expected) ->
+          it ("run " ++ file ++ " returns " ++ show expected) $ do
+            result <- runner file
+            projector result `shouldBe` expected
+      )
+      testCases
diff --git a/2023/test/Day01Spec.hs b/2023/test/Day01Spec.hs
new file mode 100644
index 0000000..c4bd831
--- /dev/null
+++ b/2023/test/Day01Spec.hs
@@ -0,0 +1,22 @@
+module Day01Spec (spec) where
+
+import Common.Tests (TestCase (..), mkPartSpec)
+import Day01 (run)
+import Test.Hspec
+
+part1TestCases :: [TestCase Int]
+part1TestCases =
+  [ TestCase "inputs/day01/part1.txt" 142,
+    TestCase "inputs/day01/input.txt" 55108
+  ]
+
+part2TestCases :: [TestCase Int]
+part2TestCases =
+  [ TestCase "inputs/day01/part2.txt" 281,
+    TestCase "inputs/day01/input.txt" 56324
+  ]
+
+spec :: Spec
+spec = do
+  mkPartSpec "Day 1/1 tests" fst run part1TestCases
+  mkPartSpec "Day 1/2 tests" snd run part2TestCases
diff --git a/2023/test/Day02Spec.hs b/2023/test/Day02Spec.hs
new file mode 100644
index 0000000..1277c93
--- /dev/null
+++ b/2023/test/Day02Spec.hs
@@ -0,0 +1,22 @@
+module Day02Spec (spec) where
+
+import Common.Tests (TestCase (..), mkPartSpec)
+import Day02 (run)
+import Test.Hspec
+
+part1TestCases :: [TestCase Int]
+part1TestCases =
+  [ TestCase "inputs/day02/example.txt" 8,
+    TestCase "inputs/day02/input.txt" 2617
+  ]
+
+part2TestCases :: [TestCase Int]
+part2TestCases =
+  [ TestCase "inputs/day02/example.txt" 2286,
+    TestCase "inputs/day02/input.txt" 59795
+  ]
+
+spec :: Spec
+spec = do
+  mkPartSpec "Day 2/1 tests" fst run part1TestCases
+  mkPartSpec "Day 2/2 tests" snd run part2TestCases
diff --git a/2023/test/Spec.hs b/2023/test/Spec.hs
new file mode 100644
index 0000000..ebe4bc1
--- /dev/null
+++ b/2023/test/Spec.hs
@@ -0,0 +1,10 @@
+module Main (main) where
+
+import qualified Day01Spec
+import qualified Day02Spec
+import Test.Hspec
+
+main :: IO ()
+main = hspec $ do
+  Day01Spec.spec
+  Day02Spec.spec