diff --git a/Shakefile.hs b/Shakefile.hs
--- a/Shakefile.hs
+++ b/Shakefile.hs
@@ -16,12 +16,12 @@
 main :: IO ()
 main = shakeMain $ do
   let pats =
-        [ "stack.yaml"
+        [ "stack*.yaml"
         , "Shakefile.hs"
         , "main//*.hs"
         , "src//*.hs"
         ]
-      pats' = delete "stack.yaml" pats
+      pats' = delete "stack*.yaml" pats
 
   -- | Haskell rules.
   --
diff --git a/main/actor.hs b/main/actor.hs
--- a/main/actor.hs
+++ b/main/actor.hs
@@ -16,6 +16,10 @@
     -- ^ Configuration file.
   , queue   :: Text
     -- ^ Queue to listen to act on.
+  , num     :: Maybe Int
+    -- ^ Number of actors to run concurrently.
+  , nocopy  :: Bool
+    -- ^ Copy working directory.
   , command :: String
     -- ^ Command to run.
   } deriving (Show, Generic)
@@ -30,4 +34,6 @@
   actMain
     (config args)
     (queue args)
+    (fromMaybe 1 $ num args)
+    (nocopy args)
     (command args)
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
@@ -65,8 +65,8 @@
 
 -- | Actor logic - poll for work, download artifacts, run command, upload artifacts.
 --
-act :: MonadConf c m => Text -> String -> m ()
-act queue command =
+act :: MonadConf c m => Text -> Bool -> String -> m ()
+act queue nocopy command =
   preConfCtx [ "label" .= LabelAct ] $
     runAmazonCtx $
       runAmazonWorkCtx queue $ do
@@ -78,7 +78,7 @@
         statsHistogram "wolf.act.poll.elapsed" (realToFrac (diffUTCTime t1 t0) :: Double) [ "queue" =. queue ]
         maybe_ token $ \token' ->
           maybe_ uid $ \uid' ->
-            withCurrentWorkDirectory uid' $ \wd ->
+            withCurrentWorkDirectory uid' nocopy $ \wd ->
               runAmazonStoreCtx uid' $ do
                 traceInfo "start" [ "dir" .= wd ]
                 t2  <- liftIO getCurrentTime
@@ -102,10 +102,10 @@
 
 -- | Run actor from main with config file.
 --
-actMain :: MonadControl m => FilePath -> Text -> String -> m ()
-actMain cf queue command =
+actMain :: MonadControl m => FilePath -> Text -> Int -> Bool -> String -> m ()
+actMain cf queue num nocopy command =
   runCtx $
     runStatsCtx $ do
       conf <- readYaml cf
       runConfCtx conf $
-        forever $ act queue command
+        runConcurrent $ replicate num $ forever $ act queue nocopy command
diff --git a/src/Network/AWS/Wolf/File.hs b/src/Network/AWS/Wolf/File.hs
--- a/src/Network/AWS/Wolf/File.hs
+++ b/src/Network/AWS/Wolf/File.hs
@@ -142,10 +142,11 @@
 
 -- | Setup a temporary work directory and copy current directory files to it.
 --
-withCurrentWorkDirectory :: MonadControl m => Text -> (FilePath -> m a) -> m a
-withCurrentWorkDirectory uid action =
+withCurrentWorkDirectory :: MonadControl m => Text -> Bool -> (FilePath -> m a) -> m a
+withCurrentWorkDirectory uid nocopy action =
   withWorkDirectory uid $ \wd ->
     withCurrentDirectory' wd $ \cd -> do
-      copyDirectoryRecursive cd wd
+      unless nocopy $
+        copyDirectoryRecursive cd wd
       action wd
 
diff --git a/wolf.cabal b/wolf.cabal
--- a/wolf.cabal
+++ b/wolf.cabal
@@ -1,5 +1,5 @@
 name: wolf
-version: 0.3.23
+version: 0.3.24
 cabal-version: >=1.22
 build-type: Simple
 license: MIT
@@ -59,7 +59,7 @@
     main-is: actor.hs
     build-depends:
         base >=4.8.2.0,
-        wolf >=0.3.23,
+        wolf,
         optparse-generic >=1.1.5
     default-language: Haskell2010
     hs-source-dirs: main
@@ -69,7 +69,7 @@
     main-is: decider.hs
     build-depends:
         base >=4.8.2.0,
-        wolf >=0.3.23,
+        wolf,
         optparse-generic >=1.1.5
     default-language: Haskell2010
     hs-source-dirs: main
@@ -79,7 +79,7 @@
     main-is: counter.hs
     build-depends:
         base >=4.8.2.0,
-        wolf >=0.3.23,
+        wolf,
         optparse-generic >=1.1.5
     default-language: Haskell2010
     hs-source-dirs: main
@@ -92,4 +92,3 @@
         shakers >=0.0.27
     default-language: Haskell2010
     ghc-options: -threaded -rtsopts -with-rtsopts=-N -Wall
-