diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,30 @@
+Copyright Jonathan Fischoff (c) 2019, 2020
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of Author name here nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/app/Main.hs b/app/Main.hs
new file mode 100644
--- /dev/null
+++ b/app/Main.hs
@@ -0,0 +1,5 @@
+import Database.Trek.Run
+import Options.Generic
+
+main :: IO ()
+main = getRecord "trek" >>= eval
diff --git a/data/2020-07-12T06-21-21_foo.sql b/data/2020-07-12T06-21-21_foo.sql
new file mode 100644
--- /dev/null
+++ b/data/2020-07-12T06-21-21_foo.sql
@@ -0,0 +1,1 @@
+CREATE SCHEMA IF NOT EXISTS test; CREATE TABLE test.foo (id SERIAL PRIMARY KEY)
diff --git a/data/2020-07-12T06-21-27_bar.sql b/data/2020-07-12T06-21-27_bar.sql
new file mode 100644
--- /dev/null
+++ b/data/2020-07-12T06-21-27_bar.sql
@@ -0,0 +1,1 @@
+CREATE SCHEMA IF NOT EXISTS test; CREATE TABLE test.bar (id SERIAL PRIMARY KEY)
diff --git a/data/2020-07-12T06-21-32_quux.sql b/data/2020-07-12T06-21-32_quux.sql
new file mode 100644
--- /dev/null
+++ b/data/2020-07-12T06-21-32_quux.sql
@@ -0,0 +1,1 @@
+CREATE SCHEMA IF NOT EXISTS test; CREATE TABLE test.quux (id SERIAL PRIMARY KEY)
diff --git a/data/dummy.txt b/data/dummy.txt
new file mode 100644
--- /dev/null
+++ b/data/dummy.txt
diff --git a/src/Database/Trek/Parser.hs b/src/Database/Trek/Parser.hs
new file mode 100644
--- /dev/null
+++ b/src/Database/Trek/Parser.hs
@@ -0,0 +1,24 @@
+module Database.Trek.Parser where
+import Options.Generic
+import Database.PostgreSQL.Simple.PartialOptions
+import qualified Options.Applicative.Builder as B
+
+data Command = Apply PartialOptions FilePath | Create String
+  deriving (Show, Eq, Generic)
+
+instance ParseRecord Command where
+  parseRecord = do
+    let applyParser
+           =  Apply
+          <$> parseRecord
+          <*> B.strArgument (B.metavar "FILEPATH")
+
+        createParser
+          = Create <$> B.strArgument (B.metavar "NAME")
+
+    B.subparser
+     (  B.command "apply"
+          (B.info applyParser (B.progDesc "Apply migrations"))
+     <> B.command "create"
+          (B.info createParser (B.progDesc "Create migrations"))
+     )
diff --git a/src/Database/Trek/Run.hs b/src/Database/Trek/Run.hs
new file mode 100644
--- /dev/null
+++ b/src/Database/Trek/Run.hs
@@ -0,0 +1,130 @@
+module Database.Trek.Run where
+import qualified Database.Trek.Db as Db
+import qualified Database.PostgreSQL.Simple.Options as P
+import qualified Database.PostgreSQL.Simple.PartialOptions as Partial
+import Data.Time.Format
+import Data.Time
+import System.IO
+import Database.Trek.Parser
+import System.FilePath.Posix
+import Data.String
+import qualified Data.ByteString.Lazy.Char8 as BSL
+import qualified Data.ByteString.Char8 as BSC
+import Crypto.Hash.SHA256
+import Control.Exception
+import Data.Typeable
+import Database.PostgreSQL.Simple
+import Data.Aeson
+import System.Exit
+import System.IO.Error
+import Control.Monad
+import Data.List.NonEmpty (nonEmpty)
+import System.Directory
+import Data.Foldable
+import qualified Database.PostgreSQL.Transact as T
+import Database.PostgreSQL.Simple.Transaction
+import qualified Data.ByteString.Base64 as Base64
+import qualified Database.PostgreSQL.Simple as Psql
+import Data.List.Split
+import Data.Maybe
+import Data.Aeson.Encode.Pretty
+
+data Errors = CouldNotParseMigration FilePath
+            | DirectoryDoesNotExist FilePath
+  deriving (Show, Eq, Typeable)
+
+instance Exception Errors
+
+eval :: Command -> IO ()
+eval cmd = do
+  let e = case cmd of
+        Create name -> putStrLn =<< create name
+        Apply partialOptions filePath -> do
+          let options = either (const $ error "Partial db options. Not possible") id
+                      $ Partial.completeOptions partialOptions
+
+          traverse_ (BSL.putStrLn . encodePretty) =<< apply options filePath
+
+  let action = try e >>= \case
+        Left err -> case err of
+          CouldNotParseMigration filePath -> do
+            hPutStrLn stderr $ "Could not parse migration: " <> filePath
+            exitWith $ ExitFailure 2
+          DirectoryDoesNotExist filePath -> do
+            hPutStrLn stderr $ "Directory does not exist: " <> filePath
+            exitWith $ ExitFailure 4
+        Right () -> pure ()
+
+  try action >>= \case
+    Left (finalErr :: SomeException) -> do
+      hPutStrLn stderr $ "Unknown error: " <> show finalErr
+      exitWith $ ExitFailure 1
+    Right () -> pure ()
+
+create :: String -> IO String
+create name = do
+  now <- getCurrentTime
+  let (dir, theFileName) = splitFileName name
+      outputFile = formatTime defaultTimeLocale "%Y-%m-%dT%H-%M-%S" now <> "_" <> theFileName
+      outputFilePath = dir </> outputFile
+  try (withFile outputFilePath WriteMode (const $ pure ())) >>= \case
+    Left i
+      | isDoesNotExistError i -> throwIO $ DirectoryDoesNotExist outputFilePath
+      | otherwise             -> throwIO i
+    Right () -> pure ()
+
+  pure outputFilePath
+
+withOptions :: P.Options -> (Connection -> IO a) -> IO a
+withOptions options f =
+  bracket (Psql.connectPostgreSQL $ P.toConnectionString options) Psql.close f
+
+parseVersion :: FilePath -> Maybe UTCTime
+parseVersion filePath = do
+  date <- listToMaybe $ splitOn "_" $ takeFileName filePath
+  parseTimeM True defaultTimeLocale "%Y-%m-%dT%H-%M-%S" date
+
+computeHash :: String -> Binary Db.Hash
+computeHash = Binary . hash . BSC.pack
+
+makeInputMigration :: FilePath -> IO Db.InputMigration
+makeInputMigration filePath = do
+  inputVersion <- maybe (throwIO $ CouldNotParseMigration filePath) pure $ parseVersion filePath
+
+  theQuery <- readFile filePath
+  let inputAction  = void $ T.execute_ $ fromString theQuery
+      inputHash    = computeHash theQuery
+
+  pure Db.InputMigration {..}
+
+newtype OutputMigration = OutputMigration Db.OutputMigration
+
+instance ToJSON OutputMigration where
+  toJSON (OutputMigration (Db.OutputMigration {..})) = object
+    [ "version" .= omVersion
+    , "hash"    .= binaryToJSON omHash
+    ]
+
+newtype OutputGroup = OutputGroup Db.OutputGroup
+  deriving (Show, Eq)
+
+instance ToJSON OutputGroup where
+  toJSON (OutputGroup (Db.OutputGroup {..})) = do
+    object
+      [ "id"         .= groupIdToJSON ogId
+      , "created_at" .= ogCreatedAt
+      , "migrations" .= fmap OutputMigration ogMigrations
+      ]
+
+binaryToJSON :: Binary BSC.ByteString -> Value
+binaryToJSON (Binary x) = toJSON $ BSC.unpack $ Base64.encode x
+
+groupIdToJSON :: Db.GroupId -> Value
+groupIdToJSON (Db.GroupId x) = binaryToJSON x
+
+apply :: P.Options -> FilePath -> IO (Maybe OutputGroup)
+apply options dirPath = do
+  xs <- mapM (makeInputMigration . (dirPath </>)) . filter ((==".sql") . takeExtension)
+    =<< listDirectory dirPath
+  withOptions options $ \conn -> fmap (fmap OutputGroup . join) $ forM (nonEmpty xs) $ \theNonEmpty ->
+    T.runDBT (Db.apply =<< Db.inputGroup theNonEmpty) ReadCommitted conn
diff --git a/test/Spec.hs b/test/Spec.hs
new file mode 100644
--- /dev/null
+++ b/test/Spec.hs
@@ -0,0 +1,1 @@
+{-# OPTIONS_GHC -F -pgmF hspec-discover #-}
diff --git a/test/Tests/Database/Trek/ParserSpec.hs b/test/Tests/Database/Trek/ParserSpec.hs
new file mode 100644
--- /dev/null
+++ b/test/Tests/Database/Trek/ParserSpec.hs
@@ -0,0 +1,19 @@
+module Tests.Database.Trek.ParserSpec where
+import Database.Trek.Parser
+import Test.Hspec
+import System.Environment
+import Options.Generic
+import Database.PostgreSQL.Simple.PartialOptions
+
+
+spec :: Spec
+spec = describe "Database.Trek.Parser" $ do
+  it "parses create" $
+    withArgs ["create", "foo"] $
+     getRecord "trek" `shouldReturn` Create "foo"
+  it "parses apply" $
+    withArgs ["apply", "/path/to/migrations"] $
+      getRecord "trek" `shouldReturn` Apply mempty "/path/to/migrations"
+  it "parses apply" $
+    withArgs ["apply", "/path/to/migrations", "--dbname=db"] $
+      getRecord "trek" `shouldReturn` Apply (mempty { dbname = pure "db"}) "/path/to/migrations"
diff --git a/test/Tests/Database/Trek/RunSpec.hs b/test/Tests/Database/Trek/RunSpec.hs
new file mode 100644
--- /dev/null
+++ b/test/Tests/Database/Trek/RunSpec.hs
@@ -0,0 +1,122 @@
+module Tests.Database.Trek.RunSpec where
+import Database.Trek.Run
+import Test.Hspec
+import Data.Maybe
+import Data.List.Split
+import Data.Time.Format
+import System.IO.Temp
+import System.Directory
+import Control.Exception
+import Data.Time
+import System.FilePath.Posix
+import Data.List.NonEmpty (NonEmpty(..))
+import qualified Database.Postgres.Temp as Temp
+import Control.Concurrent
+import Control.Concurrent.Async
+import Data.IORef
+import Data.Foldable
+import qualified Database.PostgreSQL.Simple.Options as P
+import qualified Database.Trek.Db as Db
+import Database.PostgreSQL.Simple.Types
+import Data.Time.QQ
+import qualified Database.PostgreSQL.Simple as Psql
+import Paths_trek_app (getDataDir)
+
+aroundAll :: forall a. ((a -> IO ()) -> IO ()) -> SpecWith a -> Spec
+aroundAll withFunc specWith = do
+  (var, stopper, asyncer) <- runIO $
+    (,,) <$> newEmptyMVar <*> newEmptyMVar <*> newIORef Nothing
+  let theStart :: IO a
+      theStart = do
+
+        thread <- async $ do
+          withFunc $ \x -> do
+            putMVar var x
+            takeMVar stopper
+          pure $ error "Don't evaluate this"
+
+        writeIORef asyncer $ Just thread
+
+        either pure pure =<< (wait thread `race` takeMVar var)
+
+      theStop :: a -> IO ()
+      theStop _ = do
+        putMVar stopper ()
+        traverse_ cancel =<< readIORef asyncer
+
+  beforeAll theStart $ afterAll theStop $ specWith
+
+foo :: String
+foo = "CREATE SCHEMA IF NOT EXISTS test; CREATE TABLE test.foo (id SERIAL PRIMARY KEY)"
+
+bar :: String
+bar = "CREATE SCHEMA IF NOT EXISTS test; CREATE TABLE test.bar (id SERIAL PRIMARY KEY)"
+
+quux :: String
+quux = "CREATE SCHEMA IF NOT EXISTS test; CREATE TABLE test.quux (id SERIAL PRIMARY KEY)"
+
+inputGroup :: NonEmpty FilePath -> IO FilePath
+inputGroup = error "inputGroup"
+
+withSetup :: (P.Options -> IO a) -> IO a
+withSetup f = do
+  -- Helper to throw exceptions
+  let throwE x = either throwIO pure =<< x
+
+  throwE $ Temp.withDbCache $ \dbCache -> do
+    let combinedConfig = Temp.defaultConfig <> Temp.cacheConfig dbCache
+    Temp.withConfig combinedConfig $ \db -> f $ Temp.toConnectionOptions db
+
+
+spec :: Spec
+spec = do
+  describe "Database.Trek.Run" $ do
+    it "creates a file" $ do
+      withSystemTempDirectory "trek-test" $ \tmp -> do
+        old <- getCurrentDirectory
+        bracket_ (setCurrentDirectory tmp) (setCurrentDirectory old) $ do
+          createDirectory "path"
+          let name = "path/migration.sql"
+          output <- create name
+          let (dir, theFileName) = splitFileName output
+              [date, actualName] = splitOn "_" theFileName
+          dir `shouldBe` "path/"
+          actualName `shouldBe` "migration.sql"
+          isJust (parseTimeM True defaultTimeLocale "%Y-%m-%dT%H-%M-%S" date :: Maybe UTCTime) `shouldBe` True
+          doesFileExist output `shouldReturn` True
+
+  aroundAll withSetup $ describe "Database.Trek.Run.apply" $ do
+    it "empty directory does nothing" $ \options -> withSystemTempDirectory "trek-test" $ \tmp -> do
+      apply options tmp `shouldReturn` Nothing
+      -- Doing it twice should be the same
+      apply options tmp `shouldReturn` Nothing
+
+    it "standard migrations succeed" $ \options -> do
+      dataDir <- fmap (</> "data") getDataDir
+
+      Just (OutputGroup (Db.OutputGroup {ogMigrations})) <- apply options dataDir
+      let fooM :| [barM, quuxM] = ogMigrations
+      fooM  `shouldBe` Db.OutputMigration
+        { Db.omVersion = [utcIso8601ms|2020-07-12T06:21:21.00000|]
+        , Db.omHash = Binary
+          { fromBinary = "L\DLE\137\195\169\&0\163o!I\189\253`\250\203\147\215\200\224\137S\160m{\179\227\240\ESC\194P-I" }
+          }
+      barM  `shouldBe` Db.OutputMigration
+        { Db.omVersion = [utcIso8601ms| 2020-07-12T06:21:27.00000 |]
+        , Db.omHash = Binary
+          { fromBinary = "\ETX\225\155\215\184\144\147\DLEn\SO\195\175\&4\167\208~-\244S\146\&9\215K\223i\173\EOT\209A'Z7" }
+          }
+      quuxM `shouldBe` Db.OutputMigration
+        { Db.omVersion = [utcIso8601ms| 2020-07-12T06:21:32.00000 |]
+        , Db.omHash = Binary
+          { fromBinary = "\DLE*\221\")\SO\204\207\EMdmn\b\197\233a\212-NA\133;\255\167/\t\133\139\163\222Tz" }
+          }
+
+      let action :: Psql.Connection -> IO [String]
+          action conn = fmap Psql.fromOnly <$> Psql.query_ conn
+            "SELECT CAST(table_name AS varchar) FROM information_schema.tables where table_schema = 'test' ORDER BY table_name"
+
+      withOptions options action `shouldReturn` ["bar", "foo", "quux"]
+
+    it "reapplying does nothing" $ \options -> do
+      (apply options . (</> "data") =<< getDataDir) `shouldReturn` Nothing
diff --git a/trek-app.cabal b/trek-app.cabal
new file mode 100644
--- /dev/null
+++ b/trek-app.cabal
@@ -0,0 +1,117 @@
+cabal-version: 2.0
+
+-- This file has been generated from package.yaml by hpack version 0.31.1.
+--
+-- see: https://github.com/sol/hpack
+--
+-- hash: ab7f58e2ba372fd8cc72dcb41598085a170ea1109e6522551fd9f2b2d1fd5bde
+
+name:           trek-app
+version:        0.1.0.0
+description:    Please see the README on GitHub at <https://github.com/jfischoff/trek#readme>
+homepage:       https://github.com/jfischoff/trek#readme
+bug-reports:    https://github.com/jfischoff/trek/issues
+author:         Author name here
+maintainer:     jonathangfischoff at gmail.com
+copyright:      2019 Jonathan Fischoff
+license:        BSD3
+license-file:   LICENSE
+build-type:     Simple
+tested-with: GHC==8.8.1
+category: Database
+synopsis: A PostgreSQL Database Migrator
+data-files: data/*.sql
+          , data/*.txt
+
+
+source-repository head
+  type: git
+  location: https://github.com/jfischoff/trek
+
+
+executable trek
+  main-is: Main.hs
+  hs-source-dirs: app
+  build-depends:
+      base >=4.7 && <5
+    , optparse-generic
+    , trek-app
+  default-language: Haskell2010
+  default-extensions: OverloadedStrings
+
+library
+  exposed-modules:
+      Database.Trek.Run
+    , Database.Trek.Parser
+  other-modules: Paths_trek_app
+  autogen-modules: Paths_trek_app
+  hs-source-dirs:
+      src
+  default-extensions: DataKinds GADTs KindSignatures QuasiQuotes RecordWildCards LambdaCase RankNTypes ScopedTypeVariables OverloadedStrings GeneralizedNewtypeDeriving DerivingVia DeriveGeneric DeriveAnyClass TupleSections
+  ghc-options: -Wall
+  build-depends:
+      base >=4.7 && <5
+    , bytestring
+    , process
+    , aeson
+    , time
+    , optparse-generic
+    , postgresql-simple-opts >= 0.6.0.1
+    , optparse-applicative
+    , trek-db
+    , postgres-options >= 0.2.0.0
+    , filepath
+    , aeson
+    , cryptohash-sha256
+    , postgresql-simple
+    , semigroups
+    , directory
+    , pg-transact
+    , base64-bytestring
+    , split
+    , aeson-pretty
+  default-language: Haskell2010
+
+test-suite test
+  type: exitcode-stdio-1.0
+  main-is: Spec.hs
+  other-modules: Tests.Database.Trek.ParserSpec
+               , Tests.Database.Trek.RunSpec
+               , Paths_trek_app
+  autogen-modules: Paths_trek_app
+  hs-source-dirs: test
+  default-extensions:
+      NamedFieldPuns
+    , QuasiQuotes
+    , RecordWildCards
+    , LambdaCase
+    , RankNTypes
+    , ScopedTypeVariables
+    , OverloadedStrings
+    , GeneralizedNewtypeDeriving
+    , DerivingVia
+    , DeriveGeneric
+    , DeriveAnyClass
+    , TupleSections
+  ghc-options: -threaded -rtsopts -with-rtsopts=-N -Wall
+  build-depends:
+      base >=4.7 && <5
+    , hspec
+    , hspec-discover
+    , time
+    , trek-app
+    , optparse-generic
+    , postgresql-simple-opts >= 0.6.0.1
+    , split
+    , temporary
+    , directory
+    , filepath
+    , tmp-postgres
+    , resource-pool
+    , async
+    , time-qq
+    , trek-db
+    , postgresql-simple
+    , postgres-options
+  default-language: Haskell2010
+  build-tool-depends: hspec-discover:hspec-discover