diff --git a/app/Main.hs b/app/Main.hs
index 4013660..9cb6434 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -11,6 +11,8 @@ import Text.Printf
 import System.IO
 import System.Exit
 
+import Data.Conduit.SmartSource
+
 main :: IO ()
 main = do
   args <- getArgs
@@ -20,14 +22,17 @@ main = do
     Right (opts, Just results) -> showTheResult opts results
     Right (_, Nothing) -> return ()
 
-showTheResult :: GEvalOptions -> [MetricValue] -> IO ()
+showTheResult :: GEvalOptions -> [(SourceSpec, [MetricValue])] -> IO ()
+showTheResult opts [(_, vals)] = showTheResult' opts vals
+showTheResult _ _ = error "multiple outputs not handled yet"
+
+showTheResult' :: GEvalOptions -> [MetricValue] -> IO ()
 -- do not show the metric if just one was given
-showTheResult opts [val] = putStrLn $ formatTheResult (gesPrecision $ geoSpec opts) val
-showTheResult opts [] = do
+showTheResult' opts [val] = putStrLn $ formatTheResult (gesPrecision $ geoSpec opts) val
+showTheResult' opts [] = do
   hPutStrLn stderr "no metric given, use --metric option"
   exitFailure
-
-showTheResult opts vals =  mapM_ putStrLn $ map (formatTheMetricAndResult (gesPrecision $ geoSpec opts)) $ zip (gesMetrics $ geoSpec opts) vals
+showTheResult' opts vals =  mapM_ putStrLn $ map (formatTheMetricAndResult (gesPrecision $ geoSpec opts)) $ zip (gesMetrics $ geoSpec opts) vals
 
 formatTheMetricAndResult :: Maybe Int -> (Metric, MetricValue) -> String
 formatTheMetricAndResult mPrecision (metric, val) = (show metric) ++ "\t" ++ (formatTheResult mPrecision val)
diff --git a/geval.cabal b/geval.cabal
index 3efbcc6..763b5f5 100644
--- a/geval.cabal
+++ b/geval.cabal
@@ -1,5 +1,5 @@
 name:                geval
-version:             1.0.0.1
+version:             1.1.0.0
 synopsis:            Machine learning evaluation tools
 description:         Please see README.md
 homepage:            http://github.com/name/project
diff --git a/src/GEval/Core.hs b/src/GEval/Core.hs
index 0a566c3..6001c15 100644
--- a/src/GEval/Core.hs
+++ b/src/GEval/Core.hs
@@ -268,11 +268,12 @@ isEmptyFile path = do
 
 data LineSource m = LineSource (Source m Text) SourceSpec Word32
 
-geval :: GEvalSpecification -> IO [MetricValue]
+geval :: GEvalSpecification -> IO [(SourceSpec, [MetricValue])]
 geval gevalSpec = do
   (inputSource, expectedSource, outSource) <- checkAndGetFiles False gevalSpec
-  Prelude.mapM (\metric -> gevalCore metric inputSource expectedSource outSource) metrics
-   where metrics = gesMetrics gevalSpec
+  results <- Prelude.mapM (\metric -> gevalCore metric inputSource expectedSource outSource) metrics
+  return [(outSource, results)]
+    where metrics = gesMetrics gevalSpec
 
 checkAndGetFiles :: Bool -> GEvalSpecification -> IO (SourceSpec, SourceSpec, SourceSpec)
 checkAndGetFiles forceInput gevalSpec = do
diff --git a/src/GEval/OptionsParser.hs b/src/GEval/OptionsParser.hs
index a5774a7..6647612 100644
--- a/src/GEval/OptionsParser.hs
+++ b/src/GEval/OptionsParser.hs
@@ -23,6 +23,8 @@ import GEval.Core
 import GEval.CreateChallenge
 import GEval.LineByLine
 
+import Data.Conduit.SmartSource
+
 fullOptionsParser = info (helper <*> optionsParser)
        (fullDesc
         <> progDesc "Run evaluation for tests in Gonito platform"
@@ -133,14 +135,14 @@ altMetricReader = optional $ option auto
                  <> metavar "METRIC"
                  <> help "Alternative metric (overrides --metric option)" )
 
-runGEval :: [String] -> IO (Either (ParserResult GEvalOptions) (Maybe [MetricValue]))
+runGEval :: [String] -> IO (Either (ParserResult GEvalOptions) (Maybe [(SourceSpec, [MetricValue])]))
 runGEval args = do
   ret <- runGEvalGetOptions args
   case ret of
     Left e -> return $ Left e
     Right (_, mmv) -> return $ Right mmv
 
-runGEvalGetOptions :: [String] -> IO (Either (ParserResult GEvalOptions) (GEvalOptions, Maybe [MetricValue]))
+runGEvalGetOptions :: [String] -> IO (Either (ParserResult GEvalOptions) (GEvalOptions, Maybe [(SourceSpec, [MetricValue])]))
 runGEvalGetOptions args = do
   optionExtractionResult <- getOptions args
   case optionExtractionResult of
@@ -176,10 +178,10 @@ attemptToReadOptsFromConfigFile args opts = do
   where configFilePath = (getExpectedDirectory $ geoSpec opts) </> configFileName
 
 
-runGEval'' :: GEvalOptions -> IO (Maybe [MetricValue])
+runGEval'' :: GEvalOptions -> IO (Maybe [(SourceSpec, [MetricValue])])
 runGEval'' opts = runGEval''' (geoSpecialCommand opts) (geoResultOrdering opts) (geoSpec opts)
 
-runGEval''' :: Maybe GEvalSpecialCommand -> ResultOrdering -> GEvalSpecification -> IO (Maybe [MetricValue])
+runGEval''' :: Maybe GEvalSpecialCommand -> ResultOrdering -> GEvalSpecification -> IO (Maybe [(SourceSpec, [MetricValue])])
 runGEval''' Nothing _ spec = do
   vals <- geval spec
   return $ Just vals
diff --git a/test/Spec.hs b/test/Spec.hs
index 7528885..7a71977 100644
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -47,7 +47,8 @@ main :: IO ()
 main = hspec $ do
   describe "root mean square error" $ do
     it "simple test" $ do
-      (fmap Prelude.head (geval (defaultGEvalSpecification {gesExpectedDirectory=Just "test/rmse-simple/rmse-simple", gesOutDirectory="test/rmse-simple/rmse-simple-solution"}))) `shouldReturnAlmost` 0.64549722436790
+      [(_, (val:_))] <-  geval $ defaultGEvalSpecification {gesExpectedDirectory=Just "test/rmse-simple/rmse-simple", gesOutDirectory="test/rmse-simple/rmse-simple-solution"}
+      val `shouldBeAlmost` 0.64549722436790
   describe "mean square error" $ do
     it "simple test with arguments" $
       runGEvalTest "mse-simple" `shouldReturnAlmost` 0.4166666666666667
@@ -336,8 +337,8 @@ testMatchFun 'b' 1 = True
 testMatchFun 'c' 1 = True
 testMatchFun _ _ = False
 
-extractVal :: (Either (ParserResult GEvalOptions) (Maybe [MetricValue])) -> IO MetricValue
-extractVal (Right (Just (val:_))) = return val
+extractVal :: (Either (ParserResult GEvalOptions) (Maybe [(SourceSpec, [MetricValue])])) -> IO MetricValue
+extractVal (Right (Just ([(_, val:_)]))) = return val
 
 runGEvalTest = runGEvalTestExtraOptions []