diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Revision history for pms-infra-cmdrun
 
+## 0.0.4.0 -- 2025-07-20
+
+* Added proc tool.
+
 ## 0.0.3.0 -- 2025-07-13
 
 * Added serial tool.
diff --git a/pms-infra-cmdrun.cabal b/pms-infra-cmdrun.cabal
--- a/pms-infra-cmdrun.cabal
+++ b/pms-infra-cmdrun.cabal
@@ -20,7 +20,7 @@
 -- PVP summary:     +-+------- breaking API changes
 --                  | | +----- non-breaking API additions
 --                  | | | +--- code changes with no API change
-version:            0.0.3.0
+version:            0.0.4.0
 
 -- A short (one-line) description of the package.
 synopsis:           pms-infra-cmdrun
diff --git a/src/PMS/Infra/CmdRun/DS/Core.hs b/src/PMS/Infra/CmdRun/DS/Core.hs
--- a/src/PMS/Infra/CmdRun/DS/Core.hs
+++ b/src/PMS/Infra/CmdRun/DS/Core.hs
@@ -25,6 +25,7 @@
 
 import qualified PMS.Domain.Model.DM.Type as DM
 import qualified PMS.Domain.Model.DM.Constant as DM
+import qualified PMS.Domain.Model.DS.Utility as DM
 
 import PMS.Infra.CmdRun.DM.Type
 import PMS.Infra.CmdRun.DS.Utility
@@ -56,16 +57,18 @@
 --
 cmd2task :: ConduitT DM.CmdRunCommand (IOTask ()) AppContext ()
 cmd2task = await >>= \case
-  Just cmd -> flip catchError errHdl $ do
+  Just cmd -> flip catchError (errHdl cmd) $ do
     lift (go cmd) >>= yield >> cmd2task
   Nothing -> do
     $logWarnS DM._LOGTAG "cmd2task: await returns nothing. skip."
     cmd2task
 
   where
-    errHdl :: String -> ConduitT DM.CmdRunCommand (IOTask ()) AppContext ()
-    errHdl msg = do
+    errHdl :: DM.CmdRunCommand -> String -> ConduitT DM.CmdRunCommand (IOTask ()) AppContext ()
+    errHdl cmdCmd msg = do
+      let jsonrpc = DM.getJsonRpcCmdRunCommand cmdCmd
       $logWarnS DM._LOGTAG $ T.pack $ "cmd2task: exception occurred. skip. " ++ msg
+      lift $ errorToolsCallResponse jsonrpc $ "cmd2task: exception occurred. skip. " ++ msg
       cmd2task
 
     go :: DM.CmdRunCommand -> AppContext (IOTask ())
@@ -147,8 +150,8 @@
       argsBS = DM.unRawJsonByteString $ dat^.DM.argumentsDefaultCmdRunCommandData
   args <- liftEither $ eitherDecode $ argsBS
   
-  name <- validateCommand nameTmp
-  argsStr <- validateCommandArg $ args^.argumentsStringToolParams
+  name <- liftIOE $ DM.validateCommand nameTmp
+  argsStr <- liftIOE $ DM.validateArg $ args^.argumentsStringToolParams
 #ifdef mingw32_HOST_OS
   let scriptExt = ".bat"
 #else
diff --git a/src/PMS/Infra/CmdRun/DS/Utility.hs b/src/PMS/Infra/CmdRun/DS/Utility.hs
--- a/src/PMS/Infra/CmdRun/DS/Utility.hs
+++ b/src/PMS/Infra/CmdRun/DS/Utility.hs
@@ -7,9 +7,9 @@
 import Control.Monad.IO.Class
 import Control.Monad.Except
 import Control.Monad.Reader
-import qualified Data.Text as T
-import Data.Char
-import Control.Monad
+import qualified Control.Concurrent.STM as STM
+import System.Exit
+import Control.Lens
 
 import qualified PMS.Domain.Model.DM.Type as DM
 import qualified PMS.Domain.Model.DS.Utility as DM
@@ -36,7 +36,7 @@
     errHdl :: E.SomeException -> IO (Either String a)
     errHdl = return . Left . show
 
-
+{-
 -- |
 --
 validateCommand :: String -> AppContext String
@@ -101,4 +101,42 @@
 
     forbiddenCommands :: [String]
     forbiddenCommands = ["rm", "mv", "dd", "chmod", "chown", "shutdown", "reboot", "kill", "nc", "telnet", "ssh"]
+-}
+
+-- |
+--
+toolsCallResponse :: STM.TQueue DM.McpResponse
+                  -> DM.JsonRpcRequest
+                  -> ExitCode
+                  -> String
+                  -> String
+                  -> IO ()
+toolsCallResponse resQ jsonRpc code outStr errStr = do
+  let content = [ DM.McpToolsCallResponseResultContent "text" outStr
+                , DM.McpToolsCallResponseResultContent "text" errStr
+                ]
+      result = DM.McpToolsCallResponseResult {
+                  DM._contentMcpToolsCallResponseResult = content
+                , DM._isErrorMcpToolsCallResponseResult = (ExitSuccess /= code)
+                }
+      resDat = DM.McpToolsCallResponseData jsonRpc result
+      res = DM.McpToolsCallResponse resDat
+
+  STM.atomically $ STM.writeTQueue resQ res
+
+
+-- |
+--
+errorToolsCallResponse :: DM.JsonRpcRequest -> String -> AppContext ()
+errorToolsCallResponse jsonRpc errStr = do
+  let content = [ DM.McpToolsCallResponseResultContent "text" errStr ]
+      result = DM.McpToolsCallResponseResult {
+                  DM._contentMcpToolsCallResponseResult = content
+                , DM._isErrorMcpToolsCallResponseResult = True
+                }
+      resDat = DM.McpToolsCallResponseData jsonRpc result
+      res = DM.McpToolsCallResponse resDat
+
+  resQ <- view DM.responseQueueDomainData <$> lift ask
+  liftIOE $ STM.atomically $ STM.writeTQueue resQ res