diff --git a/bench/tx-generator/src/Cardano/Benchmarking/Compiler.hs b/bench/tx-generator/src/Cardano/Benchmarking/Compiler.hs
index e6c3f146927..6d45da31d2e 100644
--- a/bench/tx-generator/src/Cardano/Benchmarking/Compiler.hs
+++ b/bench/tx-generator/src/Cardano/Benchmarking/Compiler.hs
@@ -49,8 +49,8 @@ compileToScript = do
   genesisWallet <- newWallet "genesis_wallet"
   importGenesisFunds genesisWallet
   splitWallet <- splittingPhase genesisWallet
-  addCollaterals genesisWallet splitWallet
-  benchmarkingPhase splitWallet
+  collateralWallet <- addCollaterals genesisWallet
+  benchmarkingPhase splitWallet collateralWallet
 
 initConstants :: Compiler ()
 initConstants = do
@@ -72,16 +72,18 @@ importGenesisFunds wallet = do
   emit $ ImportGenesisFund era wallet LocalSocket (KeyName "pass-partout") (KeyName "pass-partout")
   delay
 
-addCollaterals :: SrcWallet -> DstWallet -> Compiler ()
-addCollaterals src dest = do
+addCollaterals :: SrcWallet -> Compiler (Maybe WalletName)
+addCollaterals src = do
   era <- askNixOption _nix_era
   isAnyPlutusMode >>= \case
-    False -> return ()
-    True -> do
+    False -> return Nothing
+    True -> do      
       tx_fee <- askNixOption _nix_tx_fee
       safeCollateral <- _safeCollateral <$> evilFeeMagic
+      collateralWallet <- newWallet "collaeral_wallet"
       emit $ CreateChange era src src LocalSocket (PayToAddr $ KeyName "pass-partout") (safeCollateral + tx_fee) 1
-      emit $ CreateChange era src dest LocalSocket (PayToCollateral $ KeyName "pass-partout") safeCollateral 1
+      emit $ CreateChange era src collateralWallet LocalSocket (PayToCollateral $ KeyName "pass-partout") safeCollateral 1
+      return $ Just collateralWallet
 
 splittingPhase :: SrcWallet -> Compiler DstWallet
 splittingPhase srcWallet = do
@@ -104,10 +106,17 @@ splittingPhase srcWallet = do
   createChangePlutus :: AnyCardanoEra -> SplitStep -> Compiler DstWallet
   createChangePlutus era (src, dst, value, count) = do
      autoMode <- isPlutusAutoMode
-     plutusTarget <- if autoMode
-       then PayToScript <$> askNixOption _nix_plutusLoopScript <*> pure (ScriptDataNumber 0)
-       else PayToScript <$> askNixOption _nix_plutusScript     <*> (ScriptDataNumber <$> askNixOption _nix_plutusData)
-     emit $ CreateChange era src dst LocalSocket plutusTarget value count
+     scriptSpec <- if autoMode
+       then ScriptSpec <$> askNixOption _nix_plutusLoopScript <*> pure AutoScript
+       else do
+         executionUnits <- ExecutionUnits <$> askNixOption _nix_executionMemory <*> askNixOption _nix_executionSteps
+         debugMode <- askNixOption _nix_debugMode
+         budget <- (if debugMode then CheckScriptBudget else StaticScriptBudget)
+                     <$> (ScriptDataNumber <$> askNixOption _nix_plutusData)
+                     <*> (ScriptDataNumber <$> askNixOption _nix_plutusRedeemer)
+                     <*> pure executionUnits
+         ScriptSpec <$> askNixOption _nix_plutusScript <*> pure budget
+     emit $ CreateChange era src dst LocalSocket (PayToScript scriptSpec) value count
      delay
      return dst
 
@@ -138,29 +147,15 @@ unfoldSplitSequence fee value count
     -- todo: this must be in sync with Scipt/Core.hs
     maxOutputs = 30
     
-benchmarkingPhase :: WalletName -> Compiler ()
-benchmarkingPhase wallet = do
+benchmarkingPhase :: WalletName -> Maybe WalletName -> Compiler ()
+benchmarkingPhase wallet collateralWallet = do
   debugMode <- askNixOption _nix_debugMode
-  plutusMode <- askNixOption _nix_plutusMode
-  plutusAutoMode <- askNixOption _nix_plutusAutoMode
   targetNodes <- askNixOption _nix_targetNodes
   extraArgs <- evilValueMagic
   tps <- askNixOption _nix_tps
   era <- askNixOption _nix_era
   let target = if debugMode then LocalSocket else NodeToNode targetNodes
-  spendMode <- case (plutusAutoMode, plutusMode) of
-    ( True,    _ ) -> SpendAutoScript <$> askNixOption  _nix_plutusLoopScript
-    (False, True ) -> do
-      executionUnits <- ExecutionUnits <$> askNixOption _nix_executionMemory <*> askNixOption _nix_executionSteps
-      scriptBudget <- if debugMode
-        then return $ CheckScriptBudget executionUnits
-        else return $ StaticScriptBudget executionUnits
-      SpendScript <$> askNixOption _nix_plutusScript
-                  <*> pure scriptBudget
-                  <*> (ScriptDataNumber <$> askNixOption _nix_plutusData)
-                  <*> (ScriptDataNumber <$> askNixOption _nix_plutusRedeemer)
-    (False,False) ->  return SpendOutput
-  emit $ RunBenchmark era wallet target spendMode (ThreadName "tx-submit-benchmark") extraArgs tps
+  emit $ RunBenchmark era wallet target (ThreadName "tx-submit-benchmark") extraArgs collateralWallet tps
   unless debugMode $ do
     emit $ WaitBenchmark $ ThreadName "tx-submit-benchmark"
 
diff --git a/bench/tx-generator/src/Cardano/Benchmarking/FundSet.hs b/bench/tx-generator/src/Cardano/Benchmarking/FundSet.hs
index 515b47d97cc..8db545c1464 100644
--- a/bench/tx-generator/src/Cardano/Benchmarking/FundSet.hs
+++ b/bench/tx-generator/src/Cardano/Benchmarking/FundSet.hs
@@ -5,6 +5,8 @@
 {-# Language GeneralizedNewtypeDeriving #-}
 {-# Language MultiParamTypeClasses #-}
 {-# Language RankNTypes #-}
+{-# Language TypeApplications #-}
+{-# Language ScopedTypeVariables #-}
 
 module Cardano.Benchmarking.FundSet
 where
@@ -21,6 +23,7 @@ import           Cardano.Api as Api
 
 data FundInEra era = FundInEra {
     _fundTxIn :: !TxIn
+  , _fundWitness :: Witness WitCtxTxIn era
   , _fundVal  :: !(TxOutValue era)
   , _fundSigningKey :: !(Maybe (SigningKey PaymentKey))
   , _fundVariant :: !Variant
@@ -30,7 +33,7 @@ data FundInEra era = FundInEra {
 data Variant
   = PlainOldFund
   -- maybe better use the script itself instead of the filePath
-  | PlutusScriptFund !FilePath !ScriptData
+  | PlutusScriptFund
   -- A collateralFund is just a regular (PlainOldFund) on the chain,
   -- but tagged in the wallet so that it is not selected for spending.
   | CollateralFund
@@ -66,6 +69,22 @@ getFundLovelace (Fund (InAnyCardanoEra _ a)) = case _fundVal a of
   TxOutAdaOnly _era l -> l
   TxOutValue _era v -> selectLovelace v
 
+
+-- This effectively rules out era-transitions for transactions !
+-- This is not what we want !!
+getFundWitness :: forall era. IsShelleyBasedEra era => Fund -> Witness WitCtxTxIn era
+getFundWitness fund = case (cardanoEra @ era, fund) of
+  (ByronEra   , Fund (InAnyCardanoEra ByronEra   a)) -> _fundWitness a
+  (ShelleyEra , Fund (InAnyCardanoEra ShelleyEra a)) -> _fundWitness a
+  (AllegraEra , Fund (InAnyCardanoEra AllegraEra a)) -> _fundWitness a
+  (MaryEra    , Fund (InAnyCardanoEra MaryEra    a)) -> _fundWitness a
+  (AlonzoEra  , Fund (InAnyCardanoEra AlonzoEra  a)) -> _fundWitness a
+  (BabbageEra , Fund (InAnyCardanoEra BabbageEra a)) -> _fundWitness a
+-- This effectively rules out era-transitions for transactions !
+-- This is not what we want !!
+-- It should be possible to cast KeyWitnesses from one era to an other !
+  (_ , _) -> error "getFundWitness: era mismatch"
+
 data IsConfirmed = IsConfirmed | IsNotConfirmed
   deriving  (Show, Eq, Ord)
 
@@ -227,7 +246,7 @@ selectInputs allowRecycle count minTotalValue variant targetNode fs
 selectToBuffer ::
      Int
   -> Lovelace
-  -> Variant
+  -> Maybe Variant
   -> FundSet
   -> Either String [Fund]
 selectToBuffer count minValue variant fs
@@ -239,8 +258,9 @@ selectToBuffer count minValue variant fs
       ]
     else Right coins
  where
-  coins = take count $ toAscList ( Proxy :: Proxy Lovelace) (fs @=variant @= IsConfirmed @>= minValue)
-
+  coins = case variant of
+    Just v -> take count $ toAscList ( Proxy :: Proxy Lovelace) (fs @=v @= IsConfirmed @>= minValue)
+    Nothing -> take count $ toAscList ( Proxy :: Proxy Lovelace) (fs @= IsConfirmed @>= minValue)
 -- Todo: check sufficient funds and minimumValuePerUtxo
 inputsToOutputsWithFee :: Lovelace -> Int -> [Lovelace] -> [Lovelace]
 inputsToOutputsWithFee fee count inputs = map (quantityToLovelace . Quantity) outputs
diff --git a/bench/tx-generator/src/Cardano/Benchmarking/ListBufferedSelector.hs b/bench/tx-generator/src/Cardano/Benchmarking/ListBufferedSelector.hs
index 2529e95c833..6179d06d559 100644
--- a/bench/tx-generator/src/Cardano/Benchmarking/ListBufferedSelector.hs
+++ b/bench/tx-generator/src/Cardano/Benchmarking/ListBufferedSelector.hs
@@ -16,7 +16,7 @@ mkBufferedSource ::
      WalletRef
   -> Int
   -> Lovelace
-  -> Variant
+  -> Maybe Variant
   -> Int
   -> IO (Either String FundSource)
 mkBufferedSource walletRef count minValue variant munch
diff --git a/bench/tx-generator/src/Cardano/Benchmarking/PlutusExample.hs b/bench/tx-generator/src/Cardano/Benchmarking/PlutusExample.hs
index 11eedfc2d69..2a1570d63a0 100644
--- a/bench/tx-generator/src/Cardano/Benchmarking/PlutusExample.hs
+++ b/bench/tx-generator/src/Cardano/Benchmarking/PlutusExample.hs
@@ -12,47 +12,13 @@ import qualified Data.ByteString.Char8 as BSC
 import           Cardano.CLI.Shelley.Script (readFileScriptInAnyLang)
 
 import           Cardano.Api
-import           Cardano.Api.Shelley ( ProtocolParameters(..), PlutusScript(..), ReferenceScript(..)
+import           Cardano.Api.Shelley ( ProtocolParameters(..), PlutusScript(..)
                                      , fromAlonzoExUnits, protocolParamCostModels, toPlutusData)
 import           Cardano.Ledger.Alonzo.TxInfo (exBudgetToExUnits)
-import           Cardano.Benchmarking.FundSet
-import           Cardano.Benchmarking.Wallet
 
 import qualified Plutus.V1.Ledger.Api as Plutus
 import           Plutus.V1.Ledger.Contexts (ScriptContext(..), ScriptPurpose(..), TxInfo(..), TxOutRef(..))
 
-mkUtxoScript ::
-     NetworkId
-  -> (FilePath, Script PlutusScriptV1, ScriptData)
-  -> Validity
-  -> ToUTxO AlonzoEra
-mkUtxoScript networkId (scriptFile, script, txOutDatum) validity values
-  = ( map mkTxOut values
-    , newFunds
-    )
- where
-  mkTxOut v = TxOut
-                 plutusScriptAddr
-                 (lovelaceToTxOutValue v)
-                 (TxOutDatumHash ScriptDataInAlonzoEra $ hashScriptData txOutDatum)
-                 ReferenceScriptNone   
-                    
-  plutusScriptAddr = makeShelleyAddressInEra
-                       networkId
-                       (PaymentCredentialByScript $ hashScript script)
-                       NoStakeAddress
-
-  newFunds txId = zipWith (mkNewFund txId) [TxIx 0 ..] values
-
-  mkNewFund :: TxId -> TxIx -> Lovelace -> Fund
-  mkNewFund txId txIx val = Fund $ InAnyCardanoEra AlonzoEra $ FundInEra {
-      _fundTxIn = TxIn txId txIx
-    , _fundVal = lovelaceToTxOutValue val
-    , _fundSigningKey = Nothing
-    , _fundValidity = validity
-    , _fundVariant = PlutusScriptFund scriptFile txOutDatum
-    }
-
 readScript :: FilePath -> IO (Script PlutusScriptV1)
 readScript fp = do
   res <- runExceptT $ readFileScriptInAnyLang fp
diff --git a/bench/tx-generator/src/Cardano/Benchmarking/Script/Action.hs b/bench/tx-generator/src/Cardano/Benchmarking/Script/Action.hs
index 3b88f09606d..8078776d4e9 100644
--- a/bench/tx-generator/src/Cardano/Benchmarking/Script/Action.hs
+++ b/bench/tx-generator/src/Cardano/Benchmarking/Script/Action.hs
@@ -22,7 +22,8 @@ action a = case a of
   Delay t -> delay t
   ImportGenesisFund era wallet submitMode genesisKey fundKey -> importGenesisFund era wallet submitMode genesisKey fundKey
   CreateChange era sourceWallet dstWallet payMode submitMode value count -> createChange era sourceWallet dstWallet payMode submitMode value count
-  RunBenchmark era sourceWallet submitMode spendMode thread auxArgs tps -> runBenchmark era sourceWallet submitMode spendMode thread auxArgs tps
+  RunBenchmark era sourceWallet submitMode thread auxArgs collateralWallet tps
+    -> runBenchmark era sourceWallet submitMode thread auxArgs collateralWallet tps
   WaitBenchmark thread -> waitBenchmark thread
   CancelBenchmark thread -> cancelBenchmark thread
   WaitForEra era -> waitForEra era
diff --git a/bench/tx-generator/src/Cardano/Benchmarking/Script/Aeson.hs b/bench/tx-generator/src/Cardano/Benchmarking/Script/Aeson.hs
index 685bd756eb9..9413e0a0f48 100644
--- a/bench/tx-generator/src/Cardano/Benchmarking/Script/Aeson.hs
+++ b/bench/tx-generator/src/Cardano/Benchmarking/Script/Aeson.hs
@@ -73,16 +73,16 @@ instance ToJSON PayMode where
 instance FromJSON PayMode where
   parseJSON = genericParseJSON jsonOptionsUnTaggedSum
 
-instance ToJSON SpendMode where
+instance ToJSON ScriptBudget where
   toJSON     = genericToJSON jsonOptionsUnTaggedSum
   toEncoding = genericToEncoding jsonOptionsUnTaggedSum
-instance FromJSON SpendMode where
+instance FromJSON ScriptBudget where
   parseJSON = genericParseJSON jsonOptionsUnTaggedSum
 
-instance ToJSON ScriptBudget where
+instance ToJSON ScriptSpec where
   toJSON     = genericToJSON jsonOptionsUnTaggedSum
   toEncoding = genericToEncoding jsonOptionsUnTaggedSum
-instance FromJSON ScriptBudget where
+instance FromJSON ScriptSpec where
   parseJSON = genericParseJSON jsonOptionsUnTaggedSum
 
 instance ToJSON (DSum Tag Identity) where
diff --git a/bench/tx-generator/src/Cardano/Benchmarking/Script/Core.hs b/bench/tx-generator/src/Cardano/Benchmarking/Script/Core.hs
index 4b50548ee5e..0d43d00a371 100644
--- a/bench/tx-generator/src/Cardano/Benchmarking/Script/Core.hs
+++ b/bench/tx-generator/src/Cardano/Benchmarking/Script/Core.hs
@@ -32,7 +32,9 @@ import           Ouroboros.Network.Protocol.LocalTxSubmission.Type (SubmitResult
 
 import           Cardano.Benchmarking.FundSet (FundInEra (..), Validity (..), Variant (..),
                    liftAnyEra)
+
 import qualified Cardano.Benchmarking.FundSet as FundSet
+import           Cardano.Benchmarking.FundSet as FundSet (getFundTxIn)
 import           Cardano.Benchmarking.GeneratorTx as GeneratorTx (AsyncBenchmarkControl, TxGenError)
 import qualified Cardano.Benchmarking.GeneratorTx as GeneratorTx (readSigningKey, secureGenesisFund,
                    waitBenchmark, walletBenchmark)
@@ -42,7 +44,6 @@ import           Cardano.Benchmarking.GeneratorTx.NodeToNode (ConnectClient,
 import           Cardano.Benchmarking.GeneratorTx.SizedMetadata (mkMetadata)
 import           Cardano.Benchmarking.GeneratorTx.Tx as Core (keyAddress, mkFee, txInModeCardano)
 
-import           Cardano.Benchmarking.FundSet as FundSet (getFundTxIn)
 import           Cardano.Benchmarking.ListBufferedSelector
 import           Cardano.Benchmarking.OuroborosImports as Core (LocalSubmitTx, SigningKeyFile,
                    makeLocalConnectInfo, protocolToCodecConfig)
@@ -116,6 +117,7 @@ addFundToWallet wallet txIn outVal skey = do
   where
     mkFund = liftAnyEra $ \value -> FundInEra {
            _fundTxIn = txIn
+         , _fundWitness = KeyWitness KeyWitnessForSpending
          , _fundVal = value
          , _fundSigningKey = Just skey
          , _fundValidity = Confirmed
@@ -240,23 +242,28 @@ makeMetadata = do
     Right m -> return m
     Left err -> throwE $ MetadataError err
 
-runBenchmark :: AnyCardanoEra -> WalletName -> SubmitMode -> SpendMode -> ThreadName -> RunBenchmarkAux -> TPSRate -> ActionM ()
-runBenchmark era sourceWallet submitMode spendMode threadName extraArgs tps
-  = case spendMode of
-      SpendOutput -> withEra era $ runBenchmarkInEra sourceWallet submitMode threadName extraArgs tps
-      SpendScript scriptFile scriptBudget scriptData scriptRedeemer
-        -> withEra era $ runPlutusBenchmark sourceWallet submitMode scriptFile scriptBudget scriptData scriptRedeemer threadName extraArgs tps
-      SpendAutoScript scriptFile -> withEra era $ spendAutoScript sourceWallet submitMode scriptFile threadName extraArgs tps
+runBenchmark ::
+     AnyCardanoEra
+  -> WalletName
+  -> SubmitMode
+  -> ThreadName
+  -> RunBenchmarkAux
+  -> Maybe WalletName
+  -> TPSRate
+  -> ActionM ()
+runBenchmark era sourceWallet submitMode threadName extraArgs collateralWallet tps
+  = withEra era $ runBenchmarkInEra sourceWallet submitMode threadName extraArgs collateralWallet tps
 
 runBenchmarkInEra :: forall era. IsShelleyBasedEra era
   => WalletName
   -> SubmitMode
   -> ThreadName
   -> RunBenchmarkAux
+  -> Maybe WalletName
   -> TPSRate
   -> AsType era
   -> ActionM ()
-runBenchmarkInEra sourceWallet submitMode (ThreadName threadName) shape tps era = do
+runBenchmarkInEra sourceWallet submitMode (ThreadName threadName) shape collateralWallet tps era = do
   tracers  <- get BenchTracers
   networkId <- getUser TNetworkId
   fundKey <- getName $ KeyName "pass-partout" -- should be walletkey
@@ -268,21 +275,23 @@ runBenchmarkInEra sourceWallet submitMode (ThreadName threadName) shape tps era
   fundSource <- liftIO (mkBufferedSource walletRefSrc
                    (auxInputs shape)
                    (auxMinValuePerUTxO shape)
-                   PlainOldFund
+                   Nothing
                    (auxInputsPerTx shape)
                    ) >>= \case
     Right a  -> return a
     Left err -> throwE $ WalletError err
 
+  collaterals <- selectCollateralFunds collateralWallet
+
   let
     inToOut :: [Lovelace] -> [Lovelace]
     inToOut = FundSet.inputsToOutputsWithFee (auxFee shape) (auxOutputsPerTx shape)
 
-    txGenerator = genTx protocolParameters (TxInsCollateralNone, []) (mkFee (auxFee shape)) metadata (KeyWitness KeyWitnessForSpending)
-
-    toUTxO :: FundSet.Target -> FundSet.SeqNumber -> ToUTxO era
-    toUTxO target seqNumber = Wallet.mkUTxO networkId fundKey (InFlight target seqNumber)
+    txGenerator = genTx protocolParameters collaterals (mkFee (auxFee shape)) metadata
 
+    toUTxO :: FundSet.Target -> FundSet.SeqNumber -> [ToUTxO era]
+    toUTxO target seqNumber = repeat $ Wallet.mkUTxOVariant PlainOldFund networkId fundKey (InFlight target seqNumber)
+  
     fundToStore = mkWalletFundStore walletRefDst
 
     walletScript :: FundSet.Target -> WalletScript era
@@ -301,128 +310,19 @@ runBenchmarkInEra sourceWallet submitMode (ThreadName threadName) shape tps era
         Right ctl -> setName (ThreadName threadName) ctl
     _otherwise -> runWalletScriptInMode submitMode $ walletScript $ FundSet.Target "alternate-submit-mode"
 
-runPlutusBenchmark :: forall era. IsShelleyBasedEra era
-  => WalletName
-  -> SubmitMode
-  -> FilePath
-  -> ScriptBudget
-  -> ScriptData
-  -> ScriptRedeemer
-  -> ThreadName
-  -> RunBenchmarkAux
-  -> TPSRate
-  -> AsType era
-  -> ActionM ()
-runPlutusBenchmark sourceWallet submitMode scriptFile scriptBudget scriptData scriptRedeemer (ThreadName threadName) extraArgs tps era = do
-  tracers  <- get BenchTracers
-  networkId <- getUser TNetworkId
-  protocolParameters <- getProtocolParameters
-  executionUnitPrices <- case protocolParamPrices protocolParameters of
-    Just x -> return x
-    Nothing -> throwE $ WalletError "unexpected protocolParamPrices == Nothing in runPlutusBenchmark"
-  walletRefSrc <- getName sourceWallet
-  let
-    -- runBenchmark reads and write from the single sourceWallet.
-    walletRefDst = walletRefSrc
-    walletRefCollateral = walletRefSrc
-  fundKey <- getName $ KeyName "pass-partout"
-  script <- liftIO $ PlutusExample.readScript scriptFile
-  -- This does not remove the collateral from the wallet, i.e. same collateral is uses for everything.
-  -- This is fine unless a script ever fails.
-  collateralFunds <- liftIO ( askWalletRef walletRefCollateral (FundSet.selectCollateral . walletFunds)) >>= \case
+selectCollateralFunds :: forall era. IsShelleyBasedEra era
+  => Maybe WalletName
+  -> ActionM (TxInsCollateral era, [FundSet.Fund])
+selectCollateralFunds Nothing = return (TxInsCollateralNone, [])
+selectCollateralFunds (Just walletName) = do
+  cw <- getName walletName
+  collateralFunds <- liftIO ( askWalletRef cw (FundSet.selectCollateral . walletFunds)) >>= \case
     Right c -> return c
     Left err -> throwE $ WalletError err
-  baseFee <- getUser TFee
-  metadata <- makeMetadata
-
-  let costsPreRun = preExecuteScript protocolParameters script scriptData scriptRedeemer
-  executionUnits <- case (scriptBudget, costsPreRun) of
-    (_, Left err) -> throwE $ WalletError ("Cannot pre-execute Plutus script." ++ err)
-    (StaticScriptBudget exUnits, _)  -> return exUnits
-    (PreExecuteScript, Right preRun) -> return preRun
-    (CheckScriptBudget want, Right preRun)
-      -> if want == preRun then return preRun
-                           else throwE $ WalletError $ concat [
-        " Stated execution Units do not match result of pre execution. "
-      , " Stated value : ", show want
-      , " PreExecution result : ", show preRun
-      ]
-
-  let msg = mconcat [ "Plutus Benchmark :"
-                  , " Script: ", scriptFile
-                  , ", Datum: ", show scriptData
-                  , ", Redeemer: ", show scriptRedeemer
-                  , ", StatedBudget: ", show executionUnits
-                  ]
-  traceDebug msg
-
-  let
-    -- TODO --    Cardano.Ledger.Alonzo.Scripts.txscriptfee :: Prices -> ExUnits -> Coin
-    scriptFee = quantityToLovelace $ Quantity $ ceiling f
-       where
-         f :: Rational
-         f = (executionSteps e `times` priceExecutionSteps p) + (executionMemory e `times` priceExecutionMemory p)
-         e = executionUnits
-         p = executionUnitPrices
-         times w c = fromIntegral w % 1 * c
-
-    totalFee = baseFee +  fromIntegral (auxInputsPerTx extraArgs) * scriptFee
-    (Quantity minValue) = lovelaceToQuantity $ fromIntegral (auxOutputsPerTx extraArgs) * auxMinValuePerUTxO extraArgs + totalFee
-  -- this is not totally correct:
-  -- beware of rounding errors !
-    minValuePerInput = quantityToLovelace $ fromIntegral (if m==0 then d else d+1)
-      where
-        (d, m) = minValue `divMod` fromIntegral (auxInputsPerTx extraArgs)
-
-  fundSource <- liftIO (mkBufferedSource walletRefSrc
-                   (auxInputs extraArgs)
-                   minValuePerInput
-                   (PlutusScriptFund scriptFile scriptData)
-                   (auxInputsPerTx extraArgs)) >>= \case
-    Right a  -> return a
-    Left err -> throwE $ WalletError err
-
-  let
-    inToOut :: [Lovelace] -> [Lovelace]
-    inToOut = FundSet.inputsToOutputsWithFee totalFee (auxOutputsPerTx extraArgs)
---    inToOut = FundSet.inputsToOutputsWithFee totalFee 1
-
-    PlutusScript PlutusScriptV1 script' = script
-    scriptWitness :: ScriptWitness WitCtxTxIn era
-    scriptWitness = case scriptLanguageSupportedInEra (cardanoEra @ era) (PlutusScriptLanguage PlutusScriptV1) of
-      Nothing -> error $ "runPlutusBenchmark: Plutus V1 scriptlanguage not supported : in era" ++ show (cardanoEra @ era)
-      Just scriptLang -> PlutusScriptWitness
-                          scriptLang
-                          PlutusScriptV1
-                          (PScript script')
-                          (ScriptDatumForTxIn scriptData)
-                          scriptRedeemer
-                          executionUnits
-
-    collateral = case collateralSupportedInEra (cardanoEra @ era) of
-      Nothing -> error $ "runPlutusBenchmark: collateral: era not supported :" ++ show (cardanoEra @ era)
-      Just p -> (TxInsCollateral p $  map getFundTxIn collateralFunds, collateralFunds)
-
-    txGenerator = genTx protocolParameters collateral (mkFee totalFee) metadata (ScriptWitness ScriptWitnessForSpending scriptWitness)
-
-    fundToStore = mkWalletFundStore walletRefDst
-
-    toUTxO :: FundSet.Target -> FundSet.SeqNumber -> ToUTxO era
-    toUTxO target seqNumber = Wallet.mkUTxO networkId fundKey (InFlight target seqNumber)
-
-    walletScript :: FundSet.Target -> WalletScript era
-    walletScript = benchmarkWalletScript walletRefSrc txGenerator (NumberOfTxs $ auxTxCount extraArgs) (const fundSource) inToOut toUTxO fundToStore
-
-  case submitMode of
-    NodeToNode targetNodes -> do
-      connectClient <- getConnectClient
-      ret <- liftIO $ runExceptT $ GeneratorTx.walletBenchmark (btTxSubmit_ tracers) (btN2N_ tracers) connectClient
-                               threadName targetNodes tps LogErrors era (NumberOfTxs $ auxTxCount extraArgs) walletScript
-      case ret of
-        Left err -> liftTxGenError err
-        Right ctl -> setName (ThreadName threadName) ctl
-    _otherwise -> runWalletScriptInMode submitMode $ walletScript $ FundSet.Target "alternate-submit-mode"
-
+  case collateralSupportedInEra (cardanoEra @ era) of
+      Nothing -> throwE $ WalletError $ "selectCollateralFunds: collateral: era not supported :" ++ show (cardanoEra @ era)
+      Just p -> return (TxInsCollateral p $  map getFundTxIn collateralFunds, collateralFunds)
+  
 dumpToFile :: FilePath -> TxInMode CardanoMode -> ActionM ()
 dumpToFile filePath tx = liftIO $ dumpToFileIO filePath tx
 
@@ -464,74 +364,50 @@ initWallet :: WalletName -> ActionM ()
 initWallet name = liftIO Wallet.initWallet >>= setName name
 
 createChange :: AnyCardanoEra -> WalletName -> WalletName -> SubmitMode -> PayMode -> Lovelace -> Int -> ActionM ()
-createChange era sourceWallet dstWallet submitMode payMode value count = case payMode of
-  PayToAddr keyName -> withEra era $ createChangeInEra sourceWallet dstWallet submitMode PlainOldFund keyName value count
-  -- Problem here: PayToCollateral will create an output marked as collateral
-  -- and also return any change to a collateral, which makes the returned change unusable.
-  PayToCollateral keyName -> withEra era $ createChangeInEra sourceWallet dstWallet submitMode CollateralFund keyName value count
-  PayToScript scriptFile scriptData -> createChangeScriptFunds sourceWallet dstWallet submitMode scriptFile scriptData value count
-
-createChangeScriptFunds :: WalletName -> WalletName -> SubmitMode -> FilePath -> ScriptData -> Lovelace -> Int -> ActionM ()
-createChangeScriptFunds sourceWallet dstWallet submitMode scriptFile scriptData value count = do
-  walletRef <- getName dstWallet
-  networkId <- getUser TNetworkId
-  protocolParameters <- getProtocolParameters
-  _fundKey <- getName $ KeyName "pass-partout"
-  fee <- getUser TFee
-  script <- liftIO $ PlutusExample.readScript scriptFile --TODO: this should throw a file-not-found-error !
-  let
-    createCoins fundSource coins = do
-      let
---        selector :: FundSet.FundSource
---        selector = mkWalletFundSource walletRef $ FundSet.selectMinValue $ sum coins + fee
-        inOut :: [Lovelace] -> [Lovelace]
-        inOut = Wallet.includeChange fee coins
-        toUTxO = PlutusExample.mkUtxoScript networkId (scriptFile, script, scriptData) Confirmed
-        fundToStore = mkWalletFundStore walletRef
-
-      tx <- liftIO $ sourceToStoreTransaction
-                                      (genTx protocolParameters (TxInsCollateralNone, [])
-                                       (mkFee fee) TxMetadataNone (KeyWitness KeyWitnessForSpending))
-                                      fundSource inOut toUTxO fundToStore
-      return $ fmap txInModeCardano tx
-    addressMsg =  Text.unpack $ serialiseAddress $ makeShelleyAddress networkId (PaymentCredentialByScript $ hashScript script) NoStakeAddress
-  createChangeGeneric sourceWallet submitMode createCoins addressMsg value count
+createChange era sourceWallet dstWallet submitMode payMode value count
+  = withEra era $ createChangeInEra sourceWallet dstWallet submitMode payMode value count
 
 createChangeInEra :: forall era. IsShelleyBasedEra era
   => WalletName
   -> WalletName
   -> SubmitMode
-  -> Variant
-  -> KeyName
+  -> PayMode
   -> Lovelace
   -> Int
   -> AsType era
   -> ActionM ()
-createChangeInEra sourceWallet dstWallet submitMode variant keyName value count _proxy = do
-  networkId <- getUser TNetworkId
+createChangeInEra sourceWallet dstWallet submitMode payMode value count _era = do
   walletRef <- getName dstWallet
   fee <- getUser TFee
   protocolParameters <- getProtocolParameters
-  fundKey <- getName keyName
+  (toUTxO, addressMsg) <- interpretPayMode payMode
   let
     createCoins :: FundSet.FundSource -> [Lovelace] -> ActionM (Either String (TxInMode CardanoMode))
     createCoins fundSource coins = do
-      let
---        selector :: FundSet.FundSource
---        selector = mkWalletFundSource walletRef $ FundSet.selectMinValue $ sum coins + fee
-        inOut :: [Lovelace] -> [Lovelace]
-        inOut = Wallet.includeChange fee coins
-        toUTxO = Wallet.mkUTxOVariant variant networkId fundKey Confirmed
-        fundToStore = mkWalletFundStore walletRef
-
       (tx :: Either String (Tx era)) <- liftIO $ sourceToStoreTransaction
                                                   (genTx protocolParameters (TxInsCollateralNone, [])
-                                                   (mkFee fee) TxMetadataNone (KeyWitness KeyWitnessForSpending))
-                                                  fundSource inOut toUTxO fundToStore
+                                                   (mkFee fee) TxMetadataNone )
+                                                  fundSource (Wallet.includeChange fee coins) (repeat toUTxO) (mkWalletFundStore walletRef)
       return $ fmap txInModeCardano tx
-    addressMsg = Text.unpack $ serialiseAddress $ keyAddress @ era networkId fundKey
   createChangeGeneric sourceWallet submitMode createCoins addressMsg value count
 
+interpretPayMode :: forall era. IsShelleyBasedEra era => PayMode -> ActionM (ToUTxO era, String)
+interpretPayMode payMode = do
+  networkId <- getUser TNetworkId
+  case payMode of
+    PayToAddr keyName -> do
+      fundKey <- getName keyName
+      return ( Wallet.mkUTxOVariant PlainOldFund networkId fundKey Confirmed
+             , Text.unpack $ serialiseAddress $ keyAddress @ era networkId fundKey)
+    PayToCollateral keyName -> do
+      fundKey <- getName keyName
+      return ( Wallet.mkUTxOVariant CollateralFund networkId fundKey Confirmed
+             , Text.unpack $ serialiseAddress $ keyAddress @ era networkId fundKey)
+    PayToScript scriptSpec -> do
+      (witness, script, scriptData, _scriptFee) <- makePlutusContext scriptSpec
+      return ( mkUTxOScript networkId (script, scriptData) witness Confirmed
+               , Text.unpack $ serialiseAddress $ makeShelleyAddress networkId (PaymentCredentialByScript $ hashScript script) NoStakeAddress )
+  
 createChangeGeneric ::
      WalletName
   -> SubmitMode
@@ -555,7 +431,7 @@ createChangeGeneric sourceWallet submitMode createCoins addressMsg value count =
                   , " address: ", addressMsg
                   ]
   traceDebug msg
-  fundSource <- liftIO (mkBufferedSource walletRef txCount txValue PlainOldFund 1) >>= \case
+  fundSource <- liftIO (mkBufferedSource walletRef txCount txValue (Just PlainOldFund) 1) >>= \case
     Right a  -> return a
     Left err -> throwE $ WalletError err
 
@@ -581,30 +457,23 @@ It is intended to be used with the the loop script from cardano-node/plutus-exam
 loopScriptFile is the FilePath to the Plutus script that implements the delay loop. (for example in /nix/store/).
 spendAutoScript relies on a particular calling convention of the loop script.
 -}
-spendAutoScript :: forall era. IsShelleyBasedEra era
-  => WalletName
-  -> SubmitMode
-  -> FilePath
-  -> ThreadName
-  -> RunBenchmarkAux
-  -> TPSRate
-  -> AsType era
-  -> ActionM ()
-spendAutoScript sourceWallet submitMode loopScriptFile threadName extraArgs tps era = do
-  protocolParameters <- getProtocolParameters
+
+spendAutoScript ::
+     ProtocolParameters
+  -> Script PlutusScriptV1
+  -> ActionM (ScriptData, ScriptRedeemer)
+spendAutoScript protocolParameters script = do
   perTxBudget <- case protocolParamMaxTxExUnits protocolParameters of
     Nothing -> throwE $ ApiError "Cannot determine protocolParamMaxTxExUnits"
     Just b -> return b
   traceDebug $ "Plutus auto mode : Available budget per TX: " ++ show perTxBudget
 
   let
-    numInputs = fromIntegral $ auxInputsPerTx extraArgs
     budget = ExecutionUnits
-                 (executionSteps perTxBudget `div` numInputs)
-                 (executionMemory perTxBudget `div` numInputs)
+                 (executionSteps perTxBudget `div`  2) -- TODO FIX
+                 (executionMemory perTxBudget `div` 2)
   traceDebug $ "Plutus auto mode : Available budget per script run: " ++ show budget
 
-  script <- liftIO $ readScript loopScriptFile
   let
     isInLimits :: Integer -> Either String Bool
     isInLimits n = case preExecuteScript protocolParameters script (ScriptDataNumber 0) (toLoopArgument n) of
@@ -614,7 +483,7 @@ spendAutoScript sourceWallet submitMode loopScriptFile threadName extraArgs tps
   redeemer <- case startSearch isInLimits 0 searchUpperBound of
     Left err -> throwE $ ApiError $ "cannot find fitting redeemer :" ++ err
     Right n -> return $ toLoopArgument n
-  runPlutusBenchmark sourceWallet submitMode loopScriptFile PreExecuteScript (ScriptDataNumber 0) redeemer threadName extraArgs tps era
+  return (ScriptDataNumber 0, redeemer)
   where
     -- This is the hardcoded calling convention of the loop.plutus script.
     -- To loop n times one has to pass n + 1_000_000 as redeemer.
@@ -631,6 +500,81 @@ spendAutoScript sourceWallet submitMode loopScriptFile threadName extraArgs tps
              test <- f m
              if test then search f m b else search f a m
 
+makePlutusContext :: forall era. IsShelleyBasedEra era
+  => ScriptSpec
+  -> ActionM (Witness WitCtxTxIn era, Script PlutusScriptV1, ScriptData, Lovelace)
+makePlutusContext scriptSpec = do
+  protocolParameters <- getProtocolParameters
+  script <- liftIO $ PlutusExample.readScript $ scriptSpecFile scriptSpec
+
+  executionUnitPrices <- case protocolParamPrices protocolParameters of
+    Just x -> return x
+    Nothing -> throwE $ WalletError "unexpected protocolParamPrices == Nothing in runPlutusBenchmark"
+
+  perTxBudget <- case protocolParamMaxTxExUnits protocolParameters of
+    Nothing -> throwE $ ApiError "Cannot determine protocolParamMaxTxExUnits"
+    Just b -> return b
+  traceDebug $ "Plutus auto mode : Available budget per TX: " ++ show perTxBudget
+
+  (scriptData, scriptRedeemer, executionUnits) <- case scriptSpecBudget scriptSpec of
+    StaticScriptBudget sdata redeemer units -> return (sdata, redeemer, units)
+    CheckScriptBudget sdata redeemer unitsWant -> do
+      unitsPreRun <- preExecuteScriptAction protocolParameters script sdata redeemer
+      if unitsWant == unitsPreRun
+         then return (sdata, redeemer, unitsWant )
+         else throwE $ WalletError $ concat [
+              " Stated execution Units do not match result of pre execution. "
+            , " Stated value : ", show unitsWant
+            , " PreExecution result : ", show unitsPreRun
+            ]
+    AutoScript -> do
+      (sdata, redeemer) <- spendAutoScript protocolParameters script
+      preRun <- preExecuteScriptAction protocolParameters script sdata redeemer
+      return (sdata, redeemer, preRun)
+
+  let msg = mconcat [ "Plutus Benchmark :"
+                    , " Script: ", scriptSpecFile scriptSpec
+                    , ", Datum: ", show scriptData
+                    , ", Redeemer: ", show scriptRedeemer
+                    , ", StatedBudget: ", show executionUnits
+                    ]
+  traceDebug msg
+
+  let
+    -- TODO --    Cardano.Ledger.Alonzo.Scripts.txscriptfee :: Prices -> ExUnits -> Coin
+    scriptFee = quantityToLovelace $ Quantity $ ceiling f
+       where
+         f :: Rational
+         f = (executionSteps e `times` priceExecutionSteps p) + (executionMemory e `times` priceExecutionMemory p)
+         e = executionUnits
+         p = executionUnitPrices
+         times w c = fromIntegral w % 1 * c
+
+    PlutusScript PlutusScriptV1 script' = script
+    scriptWitness :: ScriptWitness WitCtxTxIn era
+    scriptWitness = case scriptLanguageSupportedInEra (cardanoEra @ era) (PlutusScriptLanguage PlutusScriptV1) of
+      Nothing -> error $ "runPlutusBenchmark: Plutus V1 scriptlanguage not supported : in era" ++ show (cardanoEra @ era)
+      Just scriptLang -> PlutusScriptWitness
+                          scriptLang
+                          PlutusScriptV1
+                          (PScript script')
+                          (ScriptDatumForTxIn scriptData)
+                          scriptRedeemer
+                          executionUnits
+
+  return (ScriptWitness ScriptWitnessForSpending scriptWitness, script, scriptData, scriptFee)
+
+preExecuteScriptAction ::
+     ProtocolParameters
+  -> Script PlutusScriptV1
+  -> ScriptData
+  -> ScriptData
+  -> ActionM ExecutionUnits
+preExecuteScriptAction protocolParameters script scriptData redeemer
+  = case preExecuteScript protocolParameters script scriptData redeemer of
+      Left err -> throwE $ WalletError ( "makePlutusContext preExecuteScript failed : " ++ show err )
+      Right costs -> return costs
+
 traceTxGeneratorVersion :: ActionM ()
 traceTxGeneratorVersion = traceBenchTxSubmit TraceTxGeneratorVersion Version.txGeneratorVersion
 
diff --git a/bench/tx-generator/src/Cardano/Benchmarking/Script/Selftest.hs b/bench/tx-generator/src/Cardano/Benchmarking/Script/Selftest.hs
index 3d0cb67bc8b..14a37b10ea9 100644
--- a/bench/tx-generator/src/Cardano/Benchmarking/Script/Selftest.hs
+++ b/bench/tx-generator/src/Cardano/Benchmarking/Script/Selftest.hs
@@ -60,8 +60,7 @@ testScript protocolFile submitMode =
   , createChange 2300000000 9000
   , RunBenchmark era wallet
     submitMode
-    SpendOutput
-    (ThreadName "walletBasedBenchmark") extraArgs (TPSRate 10.0)
+    (ThreadName "walletBasedBenchmark") extraArgs Nothing (TPSRate 10.0)
   ]
   where
     era = AnyCardanoEra AllegraEra
diff --git a/bench/tx-generator/src/Cardano/Benchmarking/Script/Types.hs b/bench/tx-generator/src/Cardano/Benchmarking/Script/Types.hs
index 725a7ba319a..263bfb5e44c 100644
--- a/bench/tx-generator/src/Cardano/Benchmarking/Script/Types.hs
+++ b/bench/tx-generator/src/Cardano/Benchmarking/Script/Types.hs
@@ -35,7 +35,7 @@ data Action where
   AddFund            :: !AnyCardanoEra -> !WalletName -> !TxIn -> !Lovelace -> !KeyName -> Action
   ImportGenesisFund  :: !AnyCardanoEra -> !WalletName -> !SubmitMode -> !KeyName -> !KeyName -> Action
   CreateChange       :: !AnyCardanoEra -> !WalletName -> !WalletName -> !SubmitMode -> !PayMode -> !Lovelace -> !Int -> Action
-  RunBenchmark       :: !AnyCardanoEra -> !WalletName -> !SubmitMode -> !SpendMode -> !ThreadName -> !RunBenchmarkAux -> !TPSRate -> Action
+  RunBenchmark       :: !AnyCardanoEra -> !WalletName -> !SubmitMode -> !ThreadName -> !RunBenchmarkAux -> Maybe WalletName -> !TPSRate -> Action
   WaitBenchmark      :: !ThreadName -> Action
   CancelBenchmark    :: !ThreadName -> Action
   Reserved           :: [String] -> Action
@@ -61,24 +61,25 @@ deriving instance Generic SubmitMode
 data PayMode where
   PayToAddr :: !KeyName -> PayMode
   PayToCollateral :: !KeyName  -> PayMode
-  PayToScript :: !FilePath -> !ScriptData -> PayMode
+  PayToScript :: !ScriptSpec -> PayMode
   deriving (Show, Eq)
 deriving instance Generic PayMode
 
-data SpendMode where
-  SpendOutput :: SpendMode
-  SpendScript :: !FilePath -> ScriptBudget -> !ScriptData -> !ScriptRedeemer -> SpendMode
-  SpendAutoScript :: !FilePath -> SpendMode
-  deriving (Show, Eq)
-deriving instance Generic SpendMode
-
 data ScriptBudget where
-  StaticScriptBudget :: !ExecutionUnits -> ScriptBudget
-  PreExecuteScript   :: ScriptBudget
-  CheckScriptBudget  :: !ExecutionUnits -> ScriptBudget
+  StaticScriptBudget :: !ScriptData -> !ScriptRedeemer -> !ExecutionUnits -> ScriptBudget
+  CheckScriptBudget  :: !ScriptData -> !ScriptRedeemer -> !ExecutionUnits -> ScriptBudget
+  AutoScript :: ScriptBudget --todo: add fraction of total available budget to use (==2 with 2 inputs !)
   deriving (Show, Eq)
 deriving instance Generic ScriptBudget
 
+data ScriptSpec = ScriptSpec
+  {
+    scriptSpecFile :: !FilePath
+  , scriptSpecBudget :: !ScriptBudget
+  }
+  deriving (Show, Eq)
+deriving instance Generic ScriptSpec
+
 data RunBenchmarkAux = RunBenchmarkAux {
     auxTxCount :: Int
   , auxFee :: Lovelace
diff --git a/bench/tx-generator/src/Cardano/Benchmarking/Wallet.hs b/bench/tx-generator/src/Cardano/Benchmarking/Wallet.hs
index ca38790cf36..9363bc239d1 100644
--- a/bench/tx-generator/src/Cardano/Benchmarking/Wallet.hs
+++ b/bench/tx-generator/src/Cardano/Benchmarking/Wallet.hs
@@ -18,7 +18,8 @@ import           Cardano.Api.Shelley (ProtocolParameters, ReferenceScript(..))
 type WalletRef = MVar Wallet
 
 type TxGenerator era = [Fund] -> [TxOut CtxTx era] -> Either String (Tx era, TxId)
-type ToUTxO era = [Lovelace] -> ([TxOut CtxTx era], TxId -> [Fund])
+
+type ToUTxO era = Lovelace -> (TxOut CtxTx era, TxIx -> TxId -> Fund)
 
 data Wallet = Wallet {
     walletSeqNumber :: !SeqNumber
@@ -78,7 +79,7 @@ sourceToStoreTransaction ::
      TxGenerator era
   -> FundSource
   -> ([Lovelace] -> [Lovelace])
-  -> ToUTxO era
+  -> [ToUTxO era]
   -> FundToStore
   -> IO (Either String (Tx era))
 sourceToStoreTransaction txGenerator fundSource inToOut mkTxOut fundToStore = do
@@ -89,11 +90,14 @@ sourceToStoreTransaction txGenerator fundSource inToOut mkTxOut fundToStore = do
   work inputFunds = do
     let
       outValues = inToOut $ map getFundLovelace inputFunds
-      (outputs, toFunds) = mkTxOut outValues
-    case txGenerator inputFunds outputs of
+      outs = zipWith ($) mkTxOut outValues
+    case txGenerator inputFunds $ map fst outs of
         Left err -> return $ Left err
         Right (tx, txId) -> do
-          fundToStore $ toFunds txId
+          let
+            fkt :: (a, TxIx -> TxId -> Fund) -> TxIx -> Fund
+            fkt a txIx = snd a txIx txId
+          fundToStore $ zipWith fkt outs [TxIx 0 ..]
           return $ Right tx
 
 includeChange :: Lovelace -> [Lovelace] -> [Lovelace] -> [Lovelace]
@@ -103,45 +107,72 @@ includeChange fee spend have = case compare changeValue 0 of
   LT -> error "genTX: Bad transaction: insufficient funds"
   where changeValue = sum have - sum spend - fee
 
-mkUTxO :: forall era. IsShelleyBasedEra era
-  => NetworkId
-  -> SigningKey PaymentKey
-  -> Validity
-  -> ToUTxO era
-mkUTxO = mkUTxOVariant PlainOldFund
-
 mkUTxOVariant :: forall era. IsShelleyBasedEra era
   => Variant
   -> NetworkId
   -> SigningKey PaymentKey
   -> Validity
   -> ToUTxO era
-mkUTxOVariant variant networkId key validity values
-  = ( map mkTxOut values
-    , newFunds
+mkUTxOVariant variant networkId key validity value
+  = ( mkTxOut value
+    , mkNewFund value
     )
  where
   mkTxOut v = TxOut (keyAddress @ era networkId key) (lovelaceToTxOutValue v) TxOutDatumNone ReferenceScriptNone
 
-  newFunds txId = zipWith (mkNewFund txId) [TxIx 0 ..] values
-
-  mkNewFund :: TxId -> TxIx -> Lovelace -> Fund
-  mkNewFund txId txIx val = Fund $ InAnyCardanoEra (cardanoEra @ era) $ FundInEra {
+  mkNewFund :: Lovelace -> TxIx -> TxId -> Fund
+  mkNewFund val txIx txId = Fund $ InAnyCardanoEra (cardanoEra @ era) $ FundInEra {
       _fundTxIn = TxIn txId txIx
+    , _fundWitness = KeyWitness KeyWitnessForSpending
     , _fundVal = lovelaceToTxOutValue val
     , _fundSigningKey = Just key
     , _fundValidity = validity
     , _fundVariant = variant
     }
 
+-- to be merged with mkUTxOVariant
+mkUTxOScript :: forall era.
+     IsShelleyBasedEra era
+  => NetworkId
+  -> (Script PlutusScriptV1, ScriptData)
+  -> Witness WitCtxTxIn era
+  -> Validity
+  -> ToUTxO era
+mkUTxOScript networkId (script, txOutDatum) witness validity value
+  = ( mkTxOut value
+    , mkNewFund value
+    )
+ where
+  plutusScriptAddr = makeShelleyAddressInEra
+                       networkId
+                       (PaymentCredentialByScript $ hashScript script)
+                       NoStakeAddress
+
+  mkTxOut v = case scriptDataSupportedInEra (cardanoEra @ era) of
+    Nothing -> error " mkUtxOScript scriptDataSupportedInEra==Nothing"
+    Just tag -> TxOut
+                  plutusScriptAddr
+                  (lovelaceToTxOutValue v)
+                  (TxOutDatumHash tag $ hashScriptData txOutDatum)
+                  ReferenceScriptNone   
+
+  mkNewFund :: Lovelace -> TxIx -> TxId -> Fund
+  mkNewFund val txIx txId = Fund $ InAnyCardanoEra (cardanoEra @ era) $ FundInEra {
+      _fundTxIn = TxIn txId txIx
+    , _fundWitness = witness
+    , _fundVal = lovelaceToTxOutValue val
+    , _fundSigningKey = Nothing
+    , _fundValidity = validity
+    , _fundVariant = PlutusScriptFund
+    }
+
 genTx :: forall era. IsShelleyBasedEra era =>
      ProtocolParameters
   -> (TxInsCollateral era, [Fund])
   -> TxFee era
   -> TxMetadataInEra era
-  -> Witness WitCtxTxIn era
   -> TxGenerator era
-genTx protocolParameters (collateral, collFunds) fee metadata witness inFunds outputs
+genTx protocolParameters (collateral, collFunds) fee metadata inFunds outputs
   = case makeTransactionBody txBodyContent of
       Left err -> error $ show err
       Right b -> Right ( signShelleyTransaction b $ map WitnessPaymentKey allKeys
@@ -150,7 +181,7 @@ genTx protocolParameters (collateral, collFunds) fee metadata witness inFunds ou
  where
   allKeys = mapMaybe getFundKey $ inFunds ++ collFunds
   txBodyContent = TxBodyContent {
-      txIns = map (\f -> (getFundTxIn f, BuildTxWith witness)) inFunds
+      txIns = map (\f -> (getFundTxIn f, BuildTxWith $ getFundWitness f)) inFunds
     , txInsCollateral = collateral
     , txInsReference = TxInsReferenceNone
     , txOuts = outputs
@@ -194,7 +225,7 @@ benchmarkWalletScript :: forall era .
   -> NumberOfTxs
   -> (Target -> FundSource)
   -> ([Lovelace] -> [Lovelace])
-  -> (Target -> SeqNumber -> ToUTxO era)
+  -> ( Target -> SeqNumber -> [ToUTxO era])
   -> FundToStore
   -> Target
   -> WalletScript era