diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Revision history for pms-domain-model
 
+## 0.0.6.0 -- 2025-07-13
+
+* Added serial tool.
+
 ## 0.0.5.0 -- 2025-07-06
 
 * Added socket tool.
diff --git a/pms-domain-model.cabal b/pms-domain-model.cabal
--- a/pms-domain-model.cabal
+++ b/pms-domain-model.cabal
@@ -1,4 +1,4 @@
-cabal-version:      3.12
+cabal-version: 2.4
 -- The cabal-version field refers to the version of the .cabal specification,
 -- and can be different from the cabal-install (the tool) version and the
 -- Cabal (the library) version you are using. As such, the Cabal (the library)
@@ -20,7 +20,7 @@
 -- PVP summary:     +-+------- breaking API changes
 --                  | | +----- non-breaking API additions
 --                  | | | +--- code changes with no API change
-version:            0.0.5.0
+version:            0.0.6.0
 
 -- A short (one-line) description of the package.
 synopsis:           pms-domain-model
@@ -55,7 +55,8 @@
 -- extra-source-files:
 
 library
-    ghc-options: -Wall -threaded -Wno-orphans -Wno-x-partial
+    ghc-options: -Wall -threaded -Wno-orphans
+--     ghc-options: -Wall -threaded -Wno-orphans -Wno-x-partial
 
     -- Modules exported by the library.
     exposed-modules:  PMS.Domain.Model.DM.TH,
@@ -70,7 +71,7 @@
     -- other-extensions:
 
     -- Other library packages from which modules are imported.
-    build-depends:    base ^>=4.21.0.0,
+    build-depends:    base >= 4.18 && < 5,
                       text,
                       mtl,
                       aeson,
@@ -89,7 +90,7 @@
     hs-source-dirs:   src
 
     -- Base language which the package is written in.
-    default-language: GHC2021
+    default-language: Haskell2010
 
 test-suite pms-domain-model-test
     ghc-options: -threaded -Wno-incomplete-uni-patterns
@@ -97,7 +98,7 @@
     -- import:           warnings
 
     -- Base language which the package is written in.
-    default-language: GHC2021
+    default-language: Haskell2010
 
     -- Modules included in this executable, other than Main.
     other-modules:    PMS.Domain.Model.DS.UtilitySpec
@@ -115,7 +116,7 @@
     main-is:          Spec.hs
 
     -- Test dependencies.
-    build-depends:    base ^>=4.21.0.0,
+    build-depends:    base >= 4.18 && < 5,
                       hspec,
                       hspec-discover,
                       data-default,
diff --git a/src/PMS/Domain/Model/DM/Constant.hs b/src/PMS/Domain/Model/DM/Constant.hs
--- a/src/PMS/Domain/Model/DM/Constant.hs
+++ b/src/PMS/Domain/Model/DM/Constant.hs
@@ -50,3 +50,8 @@
 _CRLF :: String
 _CRLF = "\r\n"
 
+
+-- |
+--
+_CR :: String
+_CR = "\r"
diff --git a/src/PMS/Domain/Model/DM/Type.hs b/src/PMS/Domain/Model/DM/Type.hs
--- a/src/PMS/Domain/Model/DM/Type.hs
+++ b/src/PMS/Domain/Model/DM/Type.hs
@@ -1343,16 +1343,81 @@
   | SocketTelnetCommand  SocketTelnetCommandData
   deriving (Show, Read, Eq)
 
+
+--------------------------------------------------------------------------------
 -- |
 --
-{-
-getJsonRpcSocketCommand :: SocketCommand -> JsonRpcRequest
-getJsonRpcSocketCommand (SocketEchoCommand      d) = d^.jsonrpcSocketEchoCommandData
-getJsonRpcSocketCommand (SocketOpenCommand       d) = d^.jsonrpcSocketOpenCommandData
-getJsonRpcSocketCommand (SocketCloseCommand d) = d^.jsonrpcSocketCloseCommandData
-getJsonRpcSocketCommand (SocketMessageCommand   d) = d^.jsonrpcSocketMessageCommandData
--}
+data SerialEchoCommandData =
+  SerialEchoCommandData {
+    _jsonrpcSerialEchoCommandData :: JsonRpcRequest
+  , _valueSerialEchoCommandData   :: String
+  } deriving (Show, Read, Eq)
 
+makeLenses ''SerialEchoCommandData
+
+-- |
+--
+data SerialOpenCommandData =
+  SerialOpenCommandData {
+    _jsonrpcSerialOpenCommandData   :: JsonRpcRequest
+  , _nameSerialOpenCommandData      :: String
+  , _argumentsSerialOpenCommandData :: RawJsonByteString
+  } deriving (Show, Read, Eq)
+
+makeLenses ''SerialOpenCommandData
+
+-- |
+--
+data SerialCloseCommandData =
+  SerialCloseCommandData {
+    _jsonrpcSerialCloseCommandData :: JsonRpcRequest
+  } deriving (Show, Read, Eq)
+  
+makeLenses ''SerialCloseCommandData
+
+
+-- |
+--
+data SerialReadCommandData =
+  SerialReadCommandData {
+    _jsonrpcSerialReadCommandData :: JsonRpcRequest
+  , _argumentsSerialReadCommandData :: RawJsonByteString
+  } deriving (Show, Read, Eq)
+  
+makeLenses ''SerialReadCommandData
+
+-- |
+--
+data SerialWriteCommandData =
+  SerialWriteCommandData {
+    _jsonrpcSerialWriteCommandData :: JsonRpcRequest
+  , _argumentsSerialWriteCommandData :: RawJsonByteString
+  } deriving (Show, Read, Eq)
+
+makeLenses ''SerialWriteCommandData
+
+
+-- |
+--
+data SerialMessageCommandData =
+  SerialMessageCommandData {
+    _jsonrpcSerialMessageCommandData   :: JsonRpcRequest
+  , _argumentsSerialMessageCommandData :: RawJsonByteString
+  } deriving (Show, Read, Eq)
+
+makeLenses ''SerialMessageCommandData
+
+-- |
+--
+data SerialCommand =
+    SerialEchoCommand    SerialEchoCommandData
+  | SerialOpenCommand    SerialOpenCommandData
+  | SerialCloseCommand   SerialCloseCommandData
+  | SerialReadCommand    SerialReadCommandData
+  | SerialWriteCommand   SerialWriteCommandData
+  | SerialMessageCommand SerialMessageCommandData
+  deriving (Show, Read, Eq)
+
 --------------------------------------------------------------------------------
 -- |
 --
@@ -1370,6 +1435,7 @@
   , _watchQueueDomainData        :: TQueue WatchCommand
   , _procspawnQueueDomainData    :: TQueue ProcSpawnCommand
   , _socketQueueDomainData       :: TQueue SocketCommand
+  , _serialQueueDomainData       :: TQueue SerialCommand
   , _promptsDomainData           :: [String]
   }
 
@@ -1394,6 +1460,7 @@
   watchQ  <- newTQueueIO
   procQ   <- newTQueueIO
   socketQ   <- newTQueueIO
+  serialQ   <- newTQueueIO
   return DomainData {
            _logDirDomainData            = Nothing
          , _logLevelDomainData          = LevelDebug
@@ -1408,6 +1475,7 @@
          , _watchQueueDomainData        = watchQ
          , _procspawnQueueDomainData    = procQ
          , _socketQueueDomainData       = socketQ
+         , _serialQueueDomainData       = serialQ
          , _promptsDomainData           = def
          }
 
diff --git a/src/PMS/Domain/Model/DS/Utility.hs b/src/PMS/Domain/Model/DS/Utility.hs
--- a/src/PMS/Domain/Model/DS/Utility.hs
+++ b/src/PMS/Domain/Model/DS/Utility.hs
@@ -103,15 +103,23 @@
   ]
 #endif
 
+
 -- |
 --
+validateMessage :: String -> IO String
+validateMessage cmd = case words cmd of
+  [] -> return cmd
+  (c : args) -> do
+    _ <- validateCommand c
+    _ <- validateArgs args
+    return cmd
+
+-- |
+--
 validateCommand :: String -> IO String
 validateCommand cmd = do
   let tcmd = T.pack cmd
 
-  when (null cmd) $
-    E.throwString "Command is empty."
-
   mapM_ (\seqStr ->
           when (seqStr `T.isInfixOf` tcmd) $
             E.throwString $ "Command contains forbidden sequence: " ++ T.unpack seqStr
@@ -128,8 +136,14 @@
     isAllowedChar :: Char -> Bool
     isAllowedChar c = isAlphaNum c || c `elem` ("-._" :: String)
 
+
 -- |
 --
+validateArgs :: [String] -> IO [String]
+validateArgs = mapM validateArg
+
+-- |
+--
 validateArg :: String -> IO String
 validateArg arg = do
   let tArg = T.pack arg
@@ -137,21 +151,6 @@
     E.throwString $ "Argument contains forbidden sequences: " ++ arg
   return arg
 
--- |
---
-validateArgs :: [String] -> IO [String]
-validateArgs = mapM validateArg
-
--- |
---
-validateMessage :: String -> IO String
-validateMessage cmd =
-  case words cmd of
-    [] -> E.throwString "Command is empty."
-    (c : args) -> do
-      _ <- validateCommand c
-      _ <- validateArgs args
-      return cmd
 
 
 -- |