diff --git a/Include/Aurora/IO/Protocol/IProtocolStack.hpp b/Include/Aurora/IO/Protocol/IProtocolStack.hpp
index 0abbad21..a3e86d92 100644
--- a/Include/Aurora/IO/Protocol/IProtocolStack.hpp
+++ b/Include/Aurora/IO/Protocol/IProtocolStack.hpp
@@ -9,6 +9,8 @@
 
 namespace Aurora::IO::Protocol
 {
+    AUE_DEFINE_VA(EProtocolWhere, eAppend, ePrepend);
+
     struct IProtocolStack :
         IProtocolBaseReader,
         IProtocolBaseWriter
@@ -20,16 +22,9 @@ namespace Aurora::IO::Protocol
          * @param uOutputBufferSize When 0, a hopefully not stupid default is used.
          * @return 
         */
-        virtual AuSPtr<IProtocolPiece> AppendInterceptor(const AuSPtr<IProtocolInterceptor> &pInterceptor, AuUInt uOutputBufferSize) = 0;
-
-        /**
-         * @brief Inserts the interceptor at the bottom of the protocol stack.
-         *        Warning: AppendInterceptorEx is preferred
-         * @param pInterceptor 
-         * @param uOutputBufferSize When 0, a hopefully not stupid default is used.
-         * @return 
-        */
-        virtual AuSPtr<IProtocolPiece> PrependInterceptor(const AuSPtr<IProtocolInterceptor> &pInterceptor, AuUInt uOutputBufferSize) = 0;
+        virtual AuSPtr<IProtocolPiece> AddInterceptor(EProtocolWhere eWhere,
+                                                      const AuSPtr<IProtocolInterceptor> &pInterceptor,
+                                                      AuUInt uOutputBufferSize) = 0;
 
         /**
          * @brief 
@@ -37,7 +32,9 @@ namespace Aurora::IO::Protocol
          * @param uOutputBufferSize When 0, a hopefully not stupid default is used.
          * @return 
         */
-        virtual AuSPtr<IProtocolPiece> AppendInterceptorEx(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize) = 0;
+        virtual AuSPtr<IProtocolPiece> AddInterceptorEx(EProtocolWhere eWhere,
+                                                        const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx,
+                                                        AuUInt uOutputBufferSize) = 0;
 
         /**
          * @brief defer to AppendInterceptorEx
@@ -45,15 +42,10 @@ namespace Aurora::IO::Protocol
          * @param uOutputBufferSize 
          * @return 
         */
-        virtual AuSPtr<IProtocolPiece> AppendInterceptorDynamicBuffer(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferDefaultSize, AuUInt uOutputBufferMaximumSize) = 0;
-
-        /**
-         * @brief Inserts the interceptor at the bottom of the protocol stack
-         * @param pInterceptorEx 
-         * @param uOutputBufferSize When 0, a hopefully not stupid default is used.
-         * @return 
-        */
-        virtual AuSPtr<IProtocolPiece> PrependInterceptorEx(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize) = 0;
+        virtual AuSPtr<IProtocolPiece> AddInterceptorDynamicBuffer(EProtocolWhere eWhere,
+                                                                   const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx,
+                                                                   AuUInt uOutputBufferDefaultSize,
+                                                                   AuUInt uOutputBufferMaximumSize) = 0;
 
         /**
          * @brief Same as AppendInterceptor, except that DoTick will repeat until the input is fully consumed.
@@ -73,14 +65,8 @@ namespace Aurora::IO::Protocol
          * @param pInterceptorEx
          * @return
         */
-        virtual AuSPtr<IProtocolPiece> AppendSingleFrameProcessor(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx) = 0;
-
-        /**
-         * @brief 
-         * @param pInterceptorEx 
-         * @return 
-        */
-        virtual AuSPtr<IProtocolPiece> PrependSingleFrameProcessor(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx) = 0;
+        virtual AuSPtr<IProtocolPiece> AddSingleFrameProcessor(EProtocolWhere eWhere,
+                                                               const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx) = 0;
 
         /**
          * @brief Defer to AppendSingleFrameProcessor
@@ -89,39 +75,19 @@ namespace Aurora::IO::Protocol
          * @param uOutputBufferSizeMax 
          * @return 
         */
-        virtual AuSPtr<IProtocolPiece> PrependSingleFrameProcessorDynamicBuffer(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferDefaultSize, AuUInt uOutputBufferMaximumSize) = 0;
+        virtual AuSPtr<IProtocolPiece> AddSingleFrameProcessorDynamicBuffer(EProtocolWhere eWhere,
+                                                                            const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx,
+                                                                            AuUInt uOutputBufferDefaultSize,
+                                                                            AuUInt uOutputBufferMaximumSize) = 0;
 
         /**
          * @brief See: AppendSingleFrameProcessor
          * @param pInterceptorEx
          * @return
         */
-        virtual AuSPtr<IProtocolPiece> AppendSingleFrameProcessorEx(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize) = 0;
-
-        /**
-         * @brief 
-         * @param pInterceptorEx 
-         * @param uOutputBufferSize 
-         * @param uOutputBufferSizeMax 
-         * @return 
-        */
-        virtual AuSPtr<IProtocolPiece> AppendSingleFrameProcessorDynamicBuffer(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferDefaultSize, AuUInt uOutputBufferMaximumSize) = 0;
-
-        /**
-         * @brief 
-         * @param pInterceptorEx 
-         * @param uOutputBufferSize 
-         * @return 
-        */
-        virtual AuSPtr<IProtocolPiece> PrependSingleFrameProcessorEx(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize) = 0;
-
-        /**
-         * @brief defer to PrependSingleFrameProcessorEx
-         * @param pInterceptorEx 
-         * @param uOutputBufferSize 
-         * @return 
-        */
-        virtual AuSPtr<IProtocolPiece> PrependInterceptorDynamicBuffer(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferDefaultSize, AuUInt uOutputBufferMaximumSize) = 0;
+        virtual AuSPtr<IProtocolPiece> AddSingleFrameProcessorEx(EProtocolWhere eWhere,
+                                                                 const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx,
+                                                                 AuUInt uOutputBufferSize) = 0;
 
         /**
          * @brief 
diff --git a/Source/IO/Protocol/AuProtocolStack.cpp b/Source/IO/Protocol/AuProtocolStack.cpp
index 07a50339..e5c1be11 100644
--- a/Source/IO/Protocol/AuProtocolStack.cpp
+++ b/Source/IO/Protocol/AuProtocolStack.cpp
@@ -24,76 +24,84 @@ namespace Aurora::IO::Protocol
     {
     }
 
-    AuSPtr<IProtocolPiece> ProtocolStack::AppendInterceptor(const AuSPtr<IProtocolInterceptor> &pInterceptor,
-                                                            AuUInt uOutputBufferSize)
+    AuSPtr<IProtocolPiece> ProtocolStack::AddInterceptor(EProtocolWhere eWhere,
+                                                         const AuSPtr<IProtocolInterceptor> &pInterceptor,
+                                                         AuUInt uOutputBufferSize)
     {
-        return this->AddInterceptorWhere(false, pInterceptor, uOutputBufferSize);
+        return this->AddInterceptorWhere(eWhere,
+                                         pInterceptor,
+                                         uOutputBufferSize);
     }
 
-    AuSPtr<IProtocolPiece> ProtocolStack::AppendInterceptorEx(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx,
-                                                              AuUInt uOutputBufferSize)
+    AuSPtr<IProtocolPiece> ProtocolStack::AddInterceptorEx(EProtocolWhere eWhere,
+                                                           const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx,
+                                                           AuUInt uOutputBufferSize)
     {
-        return this->AddInterceptorWhereEx(false, pInterceptorEx, uOutputBufferSize, false);
+        return this->AddInterceptorWhereEx(eWhere,
+                                           pInterceptorEx,
+                                           uOutputBufferSize,
+                                           false);
     }
 
-    AuSPtr<IProtocolPiece> ProtocolStack::AppendSingleFrameProcessor(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx)
+    AuSPtr<IProtocolPiece> ProtocolStack::AddSingleFrameProcessor(EProtocolWhere eWhere,
+                                                                  const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx)
     {
-        return this->AddInterceptorWhereEx(false, pInterceptorEx, 0, true);
+        return this->AddInterceptorWhereEx(eWhere,
+                                           pInterceptorEx,
+                                           0,
+                                           true);
     }
 
-    AuSPtr<IProtocolPiece> ProtocolStack::AppendSingleFrameProcessorEx(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx,
-                                                                       AuUInt uOutputBufferSize)
+    AuSPtr<IProtocolPiece> ProtocolStack::AddSingleFrameProcessorEx(EProtocolWhere eWhere,
+                                                                    const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx,
+                                                                    AuUInt uOutputBufferSize)
     {
-        return this->AddInterceptorWhereEx(false, pInterceptorEx, uOutputBufferSize, true);
+        return this->AddInterceptorWhereEx(eWhere,
+                                           pInterceptorEx, 
+                                           uOutputBufferSize,
+                                           true);
     }
 
-    AuSPtr<IProtocolPiece> ProtocolStack::PrependSingleFrameProcessor(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx)
+    AuSPtr<IProtocolPiece> ProtocolStack::AddInterceptorDynamicBuffer(EProtocolWhere eWhere,
+                                                                      const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx,
+                                                                      AuUInt uOutputBufferSize,
+                                                                      AuUInt uOutputBufferSizeMax)
     {
-        return this->AddInterceptorWhereEx(true, pInterceptorEx, 0, true);
+        return this->AddInterceptorWhereEx(eWhere,
+                                           pInterceptorEx,
+                                           uOutputBufferSize,
+                                           false,
+                                           uOutputBufferSizeMax);
     }
 
-    AuSPtr<IProtocolPiece> ProtocolStack::PrependSingleFrameProcessorEx(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx,
-                                                                       AuUInt uOutputBufferSize)
+    AuSPtr<IProtocolPiece> ProtocolStack::AddSingleFrameProcessorDynamicBuffer(EProtocolWhere eWhere,
+                                                                               const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx,
+                                                                               AuUInt uOutputBufferSize,
+                                                                               AuUInt uOutputBufferSizeMax)
     {
-        return this->AddInterceptorWhereEx(true, pInterceptorEx, uOutputBufferSize, true);
+        return this->AddInterceptorWhereEx(eWhere,
+                                           pInterceptorEx,
+                                           uOutputBufferSize,
+                                           true,
+                                           uOutputBufferSizeMax);
     }
 
-    AuSPtr<IProtocolPiece> ProtocolStack::AppendInterceptorDynamicBuffer(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize, AuUInt uOutputBufferSizeMax)
-    {
-        return this->AddInterceptorWhereEx(false, pInterceptorEx, uOutputBufferSize, false, uOutputBufferSizeMax);
-    }
-
-    AuSPtr<IProtocolPiece> ProtocolStack::PrependInterceptorDynamicBuffer(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize, AuUInt uOutputBufferSizeMax)
-    {
-        return this->AddInterceptorWhereEx(true, pInterceptorEx, uOutputBufferSize, false, uOutputBufferSizeMax);
-    }
-
-    AuSPtr<IProtocolPiece> ProtocolStack::PrependSingleFrameProcessorDynamicBuffer(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize, AuUInt uOutputBufferSizeMax)
-    {
-        return this->AddInterceptorWhereEx(true, pInterceptorEx, uOutputBufferSize, true, uOutputBufferSizeMax);
-    }
-
-    AuSPtr<IProtocolPiece> ProtocolStack::AppendSingleFrameProcessorDynamicBuffer(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize, AuUInt uOutputBufferSizeMax)
-    {
-        return this->AddInterceptorWhereEx(false, pInterceptorEx, uOutputBufferSize, true, uOutputBufferSizeMax);
-    }
-
-    AuSPtr<IProtocolPiece> ProtocolStack::PrependInterceptor(const AuSPtr<IProtocolInterceptor> &pInterceptor,
-                                                             AuUInt uOutputBufferSize)
-    {
-        return this->AddInterceptorWhere(true, pInterceptor, uOutputBufferSize);
-    }
-
-    AuSPtr<IProtocolPiece> ProtocolStack::PrependInterceptorEx(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx,
-                                                               AuUInt uOutputBufferSize)
-    {
-        return this->AddInterceptorWhereEx(true, pInterceptorEx, uOutputBufferSize, false);
-    }
-
-    AuSPtr<IProtocolPiece> ProtocolStack::AddInterceptorWhere(bool bPrepend,
+    AuSPtr<IProtocolPiece> ProtocolStack::AddInterceptorWhere(EProtocolWhere eWhere,
                                                               const AuSPtr<IProtocolInterceptor> &pInterceptor,
                                                               AuUInt uOutputBufferSize)
     {
+        if (!EProtocolWhereIsValid(eWhere))
+        {
+            SysPushErrorArg();
+            return {};
+        }
+
+        if (!pInterceptor)
+        {
+            SysPushErrorArg();
+            return {};
+        }
+
         AU_LOCK_GUARD(this->mutex);
 
         if (this->bWrittenEnd)
@@ -193,7 +201,7 @@ namespace Aurora::IO::Protocol
         pNew->pParent = this;
         pNew->pInterceptor = pInterceptor;
 
-        if (bPrepend)
+        if (eWhere == EProtocolWhere::ePrepend)
         {
             if (this->pBottomPiece)
             {
@@ -222,12 +230,24 @@ namespace Aurora::IO::Protocol
         return pNew;
     }
     
-    AuSPtr<IProtocolPiece> ProtocolStack::AddInterceptorWhereEx(bool bPrepend,
+    AuSPtr<IProtocolPiece> ProtocolStack::AddInterceptorWhereEx(EProtocolWhere eWhere,
                                                                 const AuSPtr<IProtocolInterceptorEx> &pInterceptor,
                                                                 AuUInt uOutputBufferSize,
                                                                 bool bMultipleTick,
                                                                 AuOptional<AuUInt> uMax)
     {
+        if (!EProtocolWhereIsValid(eWhere))
+        {
+            SysPushErrorArg();
+            return {};
+        }
+
+        if (!pInterceptor)
+        {
+            SysPushErrorArg();
+            return {};
+        }
+
         AU_LOCK_GUARD(this->mutex);
 
         if (this->bWrittenEnd)
@@ -343,7 +363,7 @@ namespace Aurora::IO::Protocol
         pNew->pParent = this;
         pNew->bMultipleTick = bMultipleTick;
 
-        if (bPrepend)
+        if (eWhere == EProtocolWhere::ePrepend)
         {
             if (this->pBottomPiece)
             {
@@ -1052,7 +1072,7 @@ namespace Aurora::IO::Protocol
 
             if (bSingle)
             {
-                if (!pStack->AppendSingleFrameProcessorEx(pPointer, uNextBufferSize))
+                if (!pStack->AddSingleFrameProcessorEx(EProtocolWhere::eAppend, pPointer, uNextBufferSize))
                 {
                     SysPushErrorNested();
                     return {};
@@ -1070,7 +1090,7 @@ namespace Aurora::IO::Protocol
                 }
                 else
                 {
-                    if (!pStack->AppendInterceptorEx(pPointer, uNextBufferSize))
+                    if (!pStack->AddInterceptorEx(EProtocolWhere::eAppend, pPointer, uNextBufferSize))
                     {
                         SysPushErrorNested();
                         return {};
diff --git a/Source/IO/Protocol/AuProtocolStack.hpp b/Source/IO/Protocol/AuProtocolStack.hpp
index 8545a3af..fa924394 100644
--- a/Source/IO/Protocol/AuProtocolStack.hpp
+++ b/Source/IO/Protocol/AuProtocolStack.hpp
@@ -29,29 +29,19 @@ namespace Aurora::IO::Protocol
 
         bool TryReadMore(bool bForce = false);
 
-        AuSPtr<IProtocolPiece> AppendInterceptor(const AuSPtr<IProtocolInterceptor> &pInterceptor, AuUInt uOutputBufferSize) override;
-        AuSPtr<IProtocolPiece> AppendInterceptorEx(const AuSPtr<IProtocolInterceptorEx> &pInterceptor, AuUInt uOutputBufferSize) override;
-        AuSPtr<IProtocolPiece> AppendSingleFrameProcessor(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx) override;
-        AuSPtr<IProtocolPiece> AppendSingleFrameProcessorEx(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize) override;
-
-        AuSPtr<IProtocolPiece> PrependInterceptor(const AuSPtr<IProtocolInterceptor> &pInterceptor, AuUInt uOutputBufferSize) override;
-        AuSPtr<IProtocolPiece> PrependInterceptorEx(const AuSPtr<IProtocolInterceptorEx> &pInterceptor, AuUInt uOutputBufferSize) override;
-        AuSPtr<IProtocolPiece> PrependSingleFrameProcessor(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx) override;
-        AuSPtr<IProtocolPiece> PrependSingleFrameProcessorEx(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize) override;
-        
-
-        AuSPtr<IProtocolPiece> AppendInterceptorDynamicBuffer(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize, AuUInt uOutputBufferSizeMax) override;
-        AuSPtr<IProtocolPiece> PrependInterceptorDynamicBuffer(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize, AuUInt uOutputBufferSizeMax) override;
-
-        AuSPtr<IProtocolPiece> PrependSingleFrameProcessorDynamicBuffer(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize, AuUInt uOutputBufferSizeMax) override;
-        AuSPtr<IProtocolPiece> AppendSingleFrameProcessorDynamicBuffer(const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize, AuUInt uOutputBufferSizeMax) override;
+        AuSPtr<IProtocolPiece> AddInterceptor(EProtocolWhere eWhere, const AuSPtr<IProtocolInterceptor> &pInterceptor, AuUInt uOutputBufferSize) override;
+        AuSPtr<IProtocolPiece> AddInterceptorEx(EProtocolWhere eWhere, const AuSPtr<IProtocolInterceptorEx> &pInterceptor, AuUInt uOutputBufferSize) override;
+        AuSPtr<IProtocolPiece> AddSingleFrameProcessor(EProtocolWhere eWhere, const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx) override;
+        AuSPtr<IProtocolPiece> AddSingleFrameProcessorEx(EProtocolWhere eWhere, const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize) override;
+        AuSPtr<IProtocolPiece> AddInterceptorDynamicBuffer(EProtocolWhere eWhere, const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize, AuUInt uOutputBufferSizeMax) override;
+        AuSPtr<IProtocolPiece> AddSingleFrameProcessorDynamicBuffer(EProtocolWhere eWhere, const AuSPtr<IProtocolInterceptorEx> &pInterceptorEx, AuUInt uOutputBufferSize, AuUInt uOutputBufferSizeMax) override;
 
         AuSPtr<IProtocolPiece> AddEndInterceptor(const AuSPtr<IProtocolInterceptorEx> &pInterceptor) override;
 
         void Destroy() override;
 
-        AuSPtr<IProtocolPiece> AddInterceptorWhere(bool bPrepend, const AuSPtr<IProtocolInterceptor> &pInterceptor, AuUInt uOutputBufferSize);
-        AuSPtr<IProtocolPiece> AddInterceptorWhereEx(bool bPrepend, const AuSPtr<IProtocolInterceptorEx> &pInterceptor, AuUInt uOutputBufferSize, bool bMultipleTick, AuOptional<AuUInt> uMax = {});
+        AuSPtr<IProtocolPiece> AddInterceptorWhere(EProtocolWhere eWhere, const AuSPtr<IProtocolInterceptor> &pInterceptor, AuUInt uOutputBufferSize);
+        AuSPtr<IProtocolPiece> AddInterceptorWhereEx(EProtocolWhere eWhere, const AuSPtr<IProtocolInterceptorEx> &pInterceptor, AuUInt uOutputBufferSize, bool bMultipleTick, AuOptional<AuUInt> uMax = {});
 
         AuSPtr<IStreamWriter>      AsStreamWriter() override;
         AuSPtr<Memory::ByteBuffer> AsWritableByteBuffer() override;
diff --git a/Source/IO/TLS/TLSContext.cpp b/Source/IO/TLS/TLSContext.cpp
index 95f07140..426eb4fb 100644
--- a/Source/IO/TLS/TLSContext.cpp
+++ b/Source/IO/TLS/TLSContext.cpp
@@ -170,7 +170,7 @@ namespace Aurora::IO::TLS
             return false;
         }
 
-        auto pPiece = this->pSendStack_->AppendInterceptorEx(this->GetSendInterceptor(), this->meta_.uOutPageSize);
+        auto pPiece = this->pSendStack_->AddInterceptorEx(AuIO::Protocol::EProtocolWhere::eAppend, this->GetSendInterceptor(), this->meta_.uOutPageSize);
         if (!pPiece)
         {
             SysPushErrorNet("Couldn't add TLS interceptor");
@@ -179,7 +179,7 @@ namespace Aurora::IO::TLS
 
         this->pPiece_ = pPiece;
 
-        if (!this->pRecvStack_->AppendInterceptorEx(this->GetRecvInterceptor(), this->meta_.uOutPageSize))
+        if (!this->pRecvStack_->AddInterceptorEx(AuIO::Protocol::EProtocolWhere::eAppend, this->GetRecvInterceptor(), this->meta_.uOutPageSize))
         {
             SysPushErrorNet("Couldn't add TLS interceptor");
             return false;