--- a/OrthancStone/Sources/Platforms/WebAssembly/WebAssemblyOracle.cpp	Wed Sep 23 09:41:06 2026 +0200
+++ b/OrthancStone/Sources/Platforms/WebAssembly/WebAssemblyOracle.cpp	Wed Sep 23 10:04:51 2026 +0200
@@ -99,19 +99,17 @@
   class WebAssemblyOracle::FetchContext : public boost::noncopyable
   {
   private:
-    WebAssemblyOracle&             oracle_;
-    boost::weak_ptr<IObserver>     receiver_;
-    std::unique_ptr<IOracleCommand>  command_;
-    std::string                    expectedContentType_;
+    std::unique_ptr<IOracleCallback>  callback_;
+    WebAssemblyOracle&                oracle_;
+    std::string                       expectedContentType_;
 
   public:
     FetchContext(WebAssemblyOracle& oracle,
                  boost::weak_ptr<IObserver> receiver,
                  IOracleCommand* command,
                  const std::string& expectedContentType) :
+      callback_(new OldOracleCallback(command, receiver, oracle)),
       oracle_(oracle),
-      receiver_(receiver),
-      command_(command),
       expectedContentType_(expectedContentType)
     {
       if (Orthanc::Logging::IsTraceLevelEnabled())
@@ -120,11 +118,6 @@
         LOG(TRACE) << "WebAssemblyOracle::FetchContext::FetchContext() | "
                    << "receiver address = " << std::hex << receiver.lock().get();
       }
-
-      if (command == NULL)
-      {
-        throw Orthanc::OrthancException(Orthanc::ErrorCode_NullPointer);
-      }
     }
 
     const std::string& GetExpectedContentType() const
@@ -134,29 +127,13 @@
 
     void EmitException(const Orthanc::OrthancException& exception)
     {
-      if (command_.get() == NULL)
-      {
-        throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
-      }
-      else
-      {
-        OracleCommandExceptionMessage message(*command_, exception);
-        oracle_.EmitMessage(receiver_, message);
-      }
+      callback_->NotifyError(exception);
     }
 
     void ProcessFetchResult(const std::string& answer,
                             const HttpHeaders& headers)
     {
-      if (command_.get() == NULL)
-      {
-        throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
-      }
-      else
-      {
-        OldOracleCallback callback(command_.release(), receiver_, oracle_);
-        oracle_.ProcessFetchResult(callback, answer, headers);
-      }
+      oracle_.ProcessFetchResult(*callback_, answer, headers);
     }
 
     static void SuccessCallback(emscripten_fetch_t *fetch)
@@ -802,6 +779,14 @@
   }
 
 
+  void WebAssemblyOracle::Submit(IEnvironment& environment,
+                                 const boost::shared_ptr<IOracleClient>& client,
+                                 IOracleCommand* command /* takes ownership */)
+  {
+    throw Orthanc::OrthancException(Orthanc::ErrorCode_NotImplemented);  // TODO Refactoring
+  }
+
+
   void WebAssemblyOracle::SetDicomCacheSize(size_t size)
   {
 #if ORTHANC_ENABLE_DCMTK == 1

--- a/OrthancStone/Sources/Platforms/WebAssembly/WebAssemblyOracle.h	Wed Sep 23 09:41:06 2026 +0200
+++ b/OrthancStone/Sources/Platforms/WebAssembly/WebAssemblyOracle.h	Wed Sep 23 10:04:51 2026 +0200
@@ -58,8 +58,9 @@
   class ParseDicomFromWadoCommand;
   
   class WebAssemblyOracle :
-    public IOracle,
-    public IMessageEmitter
+    public IOracle,   // TODO Refactoring - Remove old flavor
+    public IMessageEmitter,
+    public New::IOracle
   {
   private:
     typedef std::map<std::string, std::string>  HttpHeaders;
@@ -70,7 +71,7 @@
 
     void SetOrthancUrl(FetchCommand& command,
                        const std::string& uri) const;
-    
+
     void Execute(boost::weak_ptr<IObserver> receiver,
                  HttpCommand* command);    
     
@@ -110,10 +111,15 @@
     {
       oracleObservable_.EmitMessage(observer, message);
     }
-    
+
+    // TODO Refactoring - Remove old flavor
     virtual bool Schedule(boost::shared_ptr<IObserver> receiver,
                           IOracleCommand* command) ORTHANC_OVERRIDE;
 
+    virtual void Submit(IEnvironment& environment,
+                        const boost::shared_ptr<IOracleClient>& client,
+                        IOracleCommand* command /* takes ownership */) ORTHANC_OVERRIDE;
+
     IObservable& GetOracleObservable()
     {
       return oracleObservable_;