diff --git a/Shakefile.hs b/Shakefile.hs
--- a/Shakefile.hs
+++ b/Shakefile.hs
@@ -173,6 +173,7 @@
   -- | build
   --
   fake pats "build" $ \_files -> do
+    need [ "wolf.cabal" ]
     stack [ "build", "--fast" ]
 
   -- | build-error
diff --git a/src/Network/AWS/Wolf/Act.hs b/src/Network/AWS/Wolf/Act.hs
--- a/src/Network/AWS/Wolf/Act.hs
+++ b/src/Network/AWS/Wolf/Act.hs
@@ -13,7 +13,6 @@
 import Network.AWS.Wolf.Prelude
 import Network.AWS.Wolf.S3
 import Network.AWS.Wolf.SWF
-import Network.AWS.Wolf.Trace
 import Network.AWS.Wolf.Types
 import System.Process
 
diff --git a/src/Network/AWS/Wolf/Aeson.hs b/src/Network/AWS/Wolf/Aeson.hs
deleted file mode 100644
--- a/src/Network/AWS/Wolf/Aeson.hs
+++ /dev/null
@@ -1,47 +0,0 @@
-{-# LANGUAGE NoImplicitPrelude #-}
-
--- | Aeson generic deriving options.
---
-module Network.AWS.Wolf.Aeson
-  ( camelOptions
-  , snakeOptions
-  , spinalOptions
-  ) where
-
-import Data.Aeson.Types
-import Data.Char
-import Data.Text
-import Data.Text.Manipulate
-import Network.AWS.Wolf.Prelude hiding (dropWhile)
-
--- | Remove characters up to the first upper case character.
---
-unprefix :: Text -> Text
-unprefix = dropWhile (not . isUpper)
-
--- | Derive fields with camelCase.
---
-camelOptions :: Options
-camelOptions = defaultOptions
-  { fieldLabelModifier     = unpack . toCamel . unprefix . pack
-  , constructorTagModifier = unpack . toCamel . unprefix . lowerHead . pack
-  , omitNothingFields      = True
-  }
-
--- | Derive fields with snake_case.
---
-snakeOptions :: Options
-snakeOptions = defaultOptions
-  { fieldLabelModifier     = unpack . toSnake . unprefix . pack
-  , constructorTagModifier = unpack . toSnake . unprefix . lowerHead . pack
-  , omitNothingFields      = True
-  }
-
--- | Derive fields with spinal-case.
---
-spinalOptions :: Options
-spinalOptions = defaultOptions
-  { fieldLabelModifier     = unpack . toSpinal . unprefix . pack
-  , constructorTagModifier = unpack . toSpinal . unprefix . lowerHead . pack
-  , omitNothingFields      = True
-  }
diff --git a/src/Network/AWS/Wolf/Ctx.hs b/src/Network/AWS/Wolf/Ctx.hs
--- a/src/Network/AWS/Wolf/Ctx.hs
+++ b/src/Network/AWS/Wolf/Ctx.hs
@@ -14,34 +14,11 @@
   , preAmazonWorkCtx
   ) where
 
-import Control.Monad.Logger
-import Control.Monad.Reader
 import Control.Monad.Trans.AWS
 import Data.Aeson
 import Network.AWS.Wolf.Prelude
-import Network.AWS.Wolf.Trace
 import Network.AWS.Wolf.Types
 
--- | Run monad transformer, picking up logger from context.
---
-runTransT :: HasCtx c => c -> TransT c m a -> m a
-runTransT c m =
-  runReaderT (runLoggingT (unTransT m) (c ^. cTrace)) c
-
--- | Run base context.
---
-runCtx :: MonadIO m => TransT Ctx m a -> m a
-runCtx action = do
-  t <- liftIO $ newStderrTrace LevelInfo
-  runTransT (Ctx mempty t) action
-
--- | Update base context's preamble.
---
-preCtx :: MonadCtx c m => Pairs -> TransT Ctx m a -> m a
-preCtx preamble action = do
-  c <- view ctx <&> cPreamble <>~ preamble
-  runTransT c action
-
 -- | Run configuration context.
 --
 runConfCtx :: MonadCtx c m => Conf -> TransT ConfCtx m a -> m a
@@ -82,7 +59,7 @@
 runAmazonStoreCtx uid action = do
   let preamble = [ "uid" .= uid ]
   c <- view amazonCtx <&> cPreamble <>~ preamble
-  p <- (<\> uid) . view cPrefix <$> view ccConf
+  p <- (-/- uid) . view cPrefix <$> view ccConf
   runTransT (AmazonStoreCtx c uid p) action
 
 -- | Update amazon context's preamble.
diff --git a/src/Network/AWS/Wolf/Decide.hs b/src/Network/AWS/Wolf/Decide.hs
--- a/src/Network/AWS/Wolf/Decide.hs
+++ b/src/Network/AWS/Wolf/Decide.hs
@@ -12,7 +12,6 @@
 import Network.AWS.Wolf.File
 import Network.AWS.Wolf.Prelude
 import Network.AWS.Wolf.SWF
-import Network.AWS.Wolf.Trace
 import Network.AWS.Wolf.Types
 
 -- | Decider logic - poll for decisions, make decisions.
diff --git a/src/Network/AWS/Wolf/Lens.hs b/src/Network/AWS/Wolf/Lens.hs
deleted file mode 100644
--- a/src/Network/AWS/Wolf/Lens.hs
+++ /dev/null
@@ -1,39 +0,0 @@
-{-# LANGUAGE LambdaCase        #-}
-{-# LANGUAGE NoImplicitPrelude #-}
-{-# LANGUAGE OverloadedStrings #-}
-
--- | makeClassy with constraints.
---
-module Network.AWS.Wolf.Lens
-  ( makeClassyConstraints
-  ) where
-
-import Language.Haskell.TH
-import Network.AWS.Wolf.Prelude
-
--- | makeClassy with list of class constraints.
---
-makeClassyConstraints :: Name -> [Name] -> DecsQ
-makeClassyConstraints name names = do
-  decls <- makeClassy name
-  return $ addConstraints names decls
-
--- | Add constaints to a class.
---
-addConstraints :: [Name] -> [Dec] -> [Dec]
-addConstraints names = \case
-  ClassD cs n tvs f d : ds ->
-    ClassD (newConstraints names tvs ++ cs) n tvs f d : ds
-  ds -> ds
-
--- | Create new constaints.
---
-newConstraints :: [Name] -> [TyVarBndr] -> [Type]
-newConstraints ns =
-  loop where
-    loop = \case
-      PlainTV name : _tvs ->
-        flip map ns $ \n ->
-          AppT (ConT n) (VarT name)
-      _tv : tvs -> loop tvs
-      [] -> []
diff --git a/src/Network/AWS/Wolf/Prelude.hs b/src/Network/AWS/Wolf/Prelude.hs
--- a/src/Network/AWS/Wolf/Prelude.hs
+++ b/src/Network/AWS/Wolf/Prelude.hs
@@ -7,54 +7,29 @@
 module Network.AWS.Wolf.Prelude
   ( module Exports
   , runResourceT
-  , maybe_
-  , eitherThrowIO
   , runConcurrent
-  , textFromString
   , stripPrefix'
-  , (<\>)
   , MonadBaseControlIO
   , MonadMain
   ) where
 
-import BasicPrelude                    as Exports hiding (stripPrefix)
 import Control.Concurrent.Async.Lifted
-import Control.Lens                    as Exports hiding (uncons, (.=), (<.>))
 import Control.Monad.Catch
 import Control.Monad.Trans.Control
 import Control.Monad.Trans.Resource
 import Data.Text                       hiding (map)
-
--- | Maybe that returns () if Nothing
---
-maybe_ :: Monad m => Maybe a -> (a -> m ()) -> m ()
-maybe_ = flip $ maybe $ return ()
-
--- | Throw userError on either error.
---
-eitherThrowIO :: MonadIO m => Either String a -> m a
-eitherThrowIO = either (liftIO . throwIO . userError) return
+import Preamble                        as Exports hiding (stripPrefix)
 
 -- | Run a list of actions concurrently.
 --
 runConcurrent :: MonadBaseControl IO m => [m a] -> m ()
 runConcurrent = void . runConcurrently . sequenceA . map Concurrently
 
--- | Reverse of textToString
---
-textFromString :: String -> Text
-textFromString = pack
-
 -- | Strip the prefix with a '/' tacked on to the prefix.
 --
 stripPrefix' :: Text -> Text -> Maybe Text
 stripPrefix' prefix =
-  stripPrefix (prefix <\> mempty)
-
--- | </> for Text.
---
-(<\>) :: Text -> Text -> Text
-(<\>) = (<>) . (<> "/")
+  stripPrefix (prefix -/- mempty)
 
 type MonadBaseControlIO m =
   ( MonadBaseControl IO m
diff --git a/src/Network/AWS/Wolf/S3.hs b/src/Network/AWS/Wolf/S3.hs
--- a/src/Network/AWS/Wolf/S3.hs
+++ b/src/Network/AWS/Wolf/S3.hs
@@ -35,7 +35,7 @@
 getArtifact file key = do
   b    <- view cBucket <$> view ccConf
   p    <- view ascPrefix
-  gors <- send $ getObject (BucketName b) (ObjectKey (p <\> key))
+  gors <- send $ getObject (BucketName b) (ObjectKey (p -/- key))
   sinkBody (gors ^. gorsBody) (sinkFile file)
 
 -- | Put object in bucket with key.
@@ -45,5 +45,5 @@
   b          <- view cBucket <$> view ccConf
   p          <- view ascPrefix
   (sha, len) <- sourceFile file $$ getZipSink $ (,) <$> ZipSink sinkSHA256 <*> ZipSink lengthE
-  void $ send $ putObject (BucketName b) (ObjectKey (p <\> key)) $
+  void $ send $ putObject (BucketName b) (ObjectKey (p -/- key)) $
     Hashed $ HashedStream sha len $ sourceFile file
diff --git a/src/Network/AWS/Wolf/Trace.hs b/src/Network/AWS/Wolf/Trace.hs
deleted file mode 100644
--- a/src/Network/AWS/Wolf/Trace.hs
+++ /dev/null
@@ -1,89 +0,0 @@
-{-# LANGUAGE NoImplicitPrelude #-}
-{-# LANGUAGE OverloadedStrings #-}
-
--- | Tracing functionality around MonadLogger.
---
-module Network.AWS.Wolf.Trace
-  ( newStderrTrace
-  , newStdoutTrace
-  , nullTrace
-
-  , traceDebug
-  , traceInfo
-  , traceWarn
-  , traceError
-  ) where
-
-import           Control.Monad.Logger
-import           Data.Aeson
-import           Data.Aeson.Encode
-import qualified Data.HashMap.Strict      as M
-import qualified Data.Text.Lazy           as LT
-import           Data.Text.Lazy.Builder
-import           Data.Time
-import           Data.Version
-import           Network.AWS.Wolf.Prelude
-import           Network.AWS.Wolf.Types
-import           Paths_wolf
-import           System.Log.FastLogger
-
--- | Trace out only if gte configured level.
---
-levelTrace :: LogLevel -> LoggerSet -> Trace
-levelTrace level ls _loc _source level' s =
-  unless (level' < level) $ do
-    pushLogStr ls s
-    flushLogStr ls
-
--- | New logger to stderr.
---
-newStderrTrace :: MonadIO m => LogLevel -> m Trace
-newStderrTrace level =
-  liftIO $ levelTrace level <$> newStderrLoggerSet defaultBufSize
-
--- | New logger to stdout.
---
-newStdoutTrace :: MonadIO m => LogLevel -> m Trace
-newStdoutTrace level =
-  liftIO $ levelTrace level <$> newStdoutLoggerSet defaultBufSize
-
--- | Logger to nowhere.
---
-nullTrace :: Trace
-nullTrace _loc _source _level _s =
-  return ()
-
--- | Trace out event with preamble and timestamp.
---
-trace :: MonadCtx c m => (Text -> m ()) -> Text -> Pairs -> m ()
-trace logN e ps = do
-  t <- liftIO getCurrentTime
-  let preamble =
-        [ "version" .= showVersion version
-        , "run"     .= LabelWolf
-        , "event"   .= e
-        , "time"    .= t
-        ]
-  p <- view cPreamble
-  logN $ LT.toStrict $ toLazyText $ (<> singleton '\n') $
-    encodeToTextBuilder $ Object $ M.fromList $ preamble <> p <> ps
-
--- | Debug tracing.
---
-traceDebug :: MonadCtx c m => Text -> Pairs -> m ()
-traceDebug = trace logDebugN
-
--- | Info tracing.
---
-traceInfo :: MonadCtx c m => Text -> Pairs -> m ()
-traceInfo = trace logInfoN
-
--- | Warn tracing.
---
-traceWarn :: MonadCtx c m => Text -> Pairs -> m ()
-traceWarn = trace logWarnN
-
--- | Error tracing.
---
-traceError :: MonadCtx c m => Text -> Pairs -> m ()
-traceError = trace logErrorN
diff --git a/src/Network/AWS/Wolf/Types.hs b/src/Network/AWS/Wolf/Types.hs
--- a/src/Network/AWS/Wolf/Types.hs
+++ b/src/Network/AWS/Wolf/Types.hs
@@ -4,9 +4,6 @@
   ( module Exports
   ) where
 
-import Network.AWS.Wolf.Types.Alias   as Exports
 import Network.AWS.Wolf.Types.Ctx     as Exports
-import Network.AWS.Wolf.Types.Plan    as Exports
 import Network.AWS.Wolf.Types.Product as Exports
 import Network.AWS.Wolf.Types.Sum     as Exports
-import Network.AWS.Wolf.Types.Trans   as Exports
diff --git a/src/Network/AWS/Wolf/Types/Alias.hs b/src/Network/AWS/Wolf/Types/Alias.hs
deleted file mode 100644
--- a/src/Network/AWS/Wolf/Types/Alias.hs
+++ /dev/null
@@ -1,17 +0,0 @@
-{-# LANGUAGE NoImplicitPrelude #-}
-
--- | Various alias types.
---
-module Network.AWS.Wolf.Types.Alias where
-
-import Control.Monad.Logger
-import Data.Aeson
-import Network.AWS.Wolf.Prelude
-
--- | Pairs
---
-type Pairs = [(Text, Value)]
-
--- | Trace
---
-type Trace = Loc -> LogSource -> LogLevel -> LogStr -> IO ()
diff --git a/src/Network/AWS/Wolf/Types/Ctx.hs b/src/Network/AWS/Wolf/Types/Ctx.hs
--- a/src/Network/AWS/Wolf/Types/Ctx.hs
+++ b/src/Network/AWS/Wolf/Types/Ctx.hs
@@ -6,37 +6,9 @@
 --
 module Network.AWS.Wolf.Types.Ctx where
 
-import Control.Monad.Catch
-import Control.Monad.Logger
-import Control.Monad.Reader
 import Control.Monad.Trans.AWS
-import Control.Monad.Trans.Resource
-import Network.AWS.Wolf.Lens
 import Network.AWS.Wolf.Prelude
-import Network.AWS.Wolf.Types.Alias
 import Network.AWS.Wolf.Types.Product
-
--- | Ctx
---
--- Base context, supports tracing.
---
-data Ctx = Ctx
-  { _cPreamble :: Pairs
-    -- ^ Object to encode on every trace line.
-  , _cTrace    :: Trace
-    -- ^ Configurable tracing function.
-  }
-
-$(makeClassy ''Ctx)
-
-type MonadCtx c m =
-  ( MonadBaseControlIO m
-  , MonadReader c m
-  , MonadLogger m
-  , MonadCatch m
-  , MonadResource m
-  , HasCtx c
-  )
 
 -- | ConfCtx
 --
diff --git a/src/Network/AWS/Wolf/Types/Plan.hs b/src/Network/AWS/Wolf/Types/Plan.hs
deleted file mode 100644
--- a/src/Network/AWS/Wolf/Types/Plan.hs
+++ /dev/null
@@ -1,42 +0,0 @@
-{-# LANGUAGE NoImplicitPrelude #-}
-{-# LANGUAGE TemplateHaskell   #-}
-
--- | Specifications for plans.
---
-module Network.AWS.Wolf.Types.Plan where
-
-import Data.Aeson.TH
-import Network.AWS.Wolf.Aeson
-import Network.AWS.Wolf.Prelude
-
--- | Plan Task
---
--- Work task.
---
-data PlanTask = PlanTask
-  { _ptName    :: Text
-    -- ^ Name of task.
-  , _ptVersion :: Text
-    -- ^ Version of task.
-  , _ptQueue   :: Text
-    -- ^ Queue for task.
-  , _ptTimeout :: Text
-    -- ^ Timeout for task.
-  } deriving (Show, Eq)
-
-$(makeLenses ''PlanTask)
-$(deriveJSON spinalOptions ''PlanTask)
-
--- | Plan
---
--- Group of tasks.
---
-data Plan = Plan
-  { _pStart :: PlanTask
-    -- ^ Flow task.
-  , _pTasks :: [PlanTask]
-    -- ^ Worker tasks.
-  } deriving (Show, Eq)
-
-$(makeLenses ''Plan)
-$(deriveJSON spinalOptions ''Plan)
diff --git a/src/Network/AWS/Wolf/Types/Product.hs b/src/Network/AWS/Wolf/Types/Product.hs
--- a/src/Network/AWS/Wolf/Types/Product.hs
+++ b/src/Network/AWS/Wolf/Types/Product.hs
@@ -6,7 +6,6 @@
 module Network.AWS.Wolf.Types.Product where
 
 import Data.Aeson.TH
-import Network.AWS.Wolf.Aeson
 import Network.AWS.Wolf.Prelude
 
 -- | Conf
@@ -38,3 +37,35 @@
 
 $(makeLenses ''Control)
 $(deriveJSON spinalOptions ''Control)
+
+-- | Plan Task
+--
+-- Work task.
+--
+data PlanTask = PlanTask
+  { _ptName    :: Text
+    -- ^ Name of task.
+  , _ptVersion :: Text
+    -- ^ Version of task.
+  , _ptQueue   :: Text
+    -- ^ Queue for task.
+  , _ptTimeout :: Text
+    -- ^ Timeout for task.
+  } deriving (Show, Eq)
+
+$(makeLenses ''PlanTask)
+$(deriveJSON spinalOptions ''PlanTask)
+
+-- | Plan
+--
+-- Group of tasks.
+--
+data Plan = Plan
+  { _pStart :: PlanTask
+    -- ^ Flow task.
+  , _pTasks :: [PlanTask]
+    -- ^ Worker tasks.
+  } deriving (Show, Eq)
+
+$(makeLenses ''Plan)
+$(deriveJSON spinalOptions ''Plan)
diff --git a/src/Network/AWS/Wolf/Types/Sum.hs b/src/Network/AWS/Wolf/Types/Sum.hs
--- a/src/Network/AWS/Wolf/Types/Sum.hs
+++ b/src/Network/AWS/Wolf/Types/Sum.hs
@@ -6,7 +6,6 @@
 module Network.AWS.Wolf.Types.Sum where
 
 import Data.Aeson.TH
-import Network.AWS.Wolf.Aeson
 import Network.AWS.Wolf.Prelude
 
 -- | LabelType
diff --git a/src/Network/AWS/Wolf/Types/Trans.hs b/src/Network/AWS/Wolf/Types/Trans.hs
deleted file mode 100644
--- a/src/Network/AWS/Wolf/Types/Trans.hs
+++ /dev/null
@@ -1,47 +0,0 @@
-{-# LANGUAGE FlexibleInstances          #-}
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE MultiParamTypeClasses      #-}
-{-# LANGUAGE NoImplicitPrelude          #-}
-{-# LANGUAGE TypeFamilies               #-}
-{-# LANGUAGE UndecidableInstances       #-}
-
--- | Monad transformer.
---
-module Network.AWS.Wolf.Types.Trans where
-
-import Control.Monad.Base
-import Control.Monad.Catch
-import Control.Monad.Logger
-import Control.Monad.Reader
-import Control.Monad.Trans.Control
-import Control.Monad.Trans.Resource
-import Network.AWS.Wolf.Prelude
-
--- | Monad transformer for reading and logging.
---
-newtype TransT c m a = TransT
-  { unTransT :: LoggingT (ReaderT c m) a
-    -- ^ LoggingT and ReaderT transformer.
-  } deriving (Functor, Applicative, Monad, MonadLogger, MonadReader c, MonadIO, MonadThrow, MonadCatch, MonadMask)
-
-instance MonadBase b m => MonadBase b (TransT c m) where
-  liftBase = liftBaseDefault
-
-instance MonadBaseControl b m => MonadBaseControl b (TransT c m) where
-    type StM (TransT c m) a = ComposeSt (TransT c) m a
-    liftBaseWith = defaultLiftBaseWith
-    restoreM = defaultRestoreM
-
-instance MonadTransControl (TransT c) where
-  type StT (TransT c) a = StT (ReaderT c) a
-  liftWith f = TransT $
-    liftWith $ \g ->
-      liftWith $ \h ->
-        f (h . g . unTransT)
-  restoreT = TransT . restoreT . restoreT
-
-instance MonadTrans (TransT c) where
-  lift = TransT . lift . lift
-
-instance MonadResource m => MonadResource (TransT c m) where
-  liftResourceT = lift . liftResourceT
diff --git a/wolf.cabal b/wolf.cabal
--- a/wolf.cabal
+++ b/wolf.cabal
@@ -1,5 +1,5 @@
 name:                wolf
-version:             0.3.0
+version:             0.3.1
 synopsis:            Amazon Simple Workflow Service Wrapper.
 homepage:            https://github.com/swift-nav/wolf
 license:             MIT
@@ -30,22 +30,16 @@
                      , Network.AWS.Flow.Types
                      , Network.AWS.Flow.Uid
                      , Network.AWS.Wolf.Act
-                     , Network.AWS.Wolf.Aeson
                      , Network.AWS.Wolf.Ctx
                      , Network.AWS.Wolf.Decide
                      , Network.AWS.Wolf.File
-                     , Network.AWS.Wolf.Lens
                      , Network.AWS.Wolf.Prelude
                      , Network.AWS.Wolf.S3
                      , Network.AWS.Wolf.SWF
-                     , Network.AWS.Wolf.Trace
                      , Network.AWS.Wolf.Types
-                     , Network.AWS.Wolf.Types.Alias
                      , Network.AWS.Wolf.Types.Ctx
-                     , Network.AWS.Wolf.Types.Plan
                      , Network.AWS.Wolf.Types.Product
                      , Network.AWS.Wolf.Types.Sum
-                     , Network.AWS.Wolf.Types.Trans
                      , Paths_wolf
   default-language:    Haskell2010
   hs-source-dirs:      src
@@ -76,6 +70,7 @@
                      , mtl
                      , mtl-compat
                      , optparse-applicative
+                     , preamble
                      , process
                      , regex-applicative
                      , regex-compat