--- a/Plugin/DicomWebFormatter.cpp	Mon Aug 21 15:16:23 2023 +0200
+++ b/Plugin/DicomWebFormatter.cpp	Mon Aug 21 16:33:27 2023 +0200
@@ -289,8 +289,8 @@
   }
 
 
-  void DicomWebFormatter::HttpWriter::AddDicomWebSerializedJson(const void* data,
-                                                                size_t size)
+  void DicomWebFormatter::HttpWriter::AddDicomWebInstanceSerializedJson(const void* data,
+                                                                        size_t size)
   {
     if (isXml_)
     {
@@ -318,6 +318,41 @@
     jsonBuffer_.AddChunk(data, size);
   }
 
+  void DicomWebFormatter::HttpWriter::AddDicomWebSeriesSerializedJson(const void* data,
+                                                                      size_t size)
+  {
+    if (isXml_)
+    {
+      // This function can only be used in the JSON case
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
+    }
+
+#if !defined(NDEBUG)  // In debug mode, check that the value is actually a JSON string
+    Json::Value json;
+    if (!OrthancPlugins::ReadJson(json, data, size))
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_BadFileFormat);
+    }
+#endif
+    
+    if (size <= 2 ||
+        reinterpret_cast<const char*>(data)[0] != '[' ||
+        reinterpret_cast<const char*>(data)[size-1] != ']')
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_BadFileFormat, "The series metadata json does not contain an array.");
+    }
+
+    if (first_)
+    {
+      first_ = false;
+    }
+    else
+    {
+      jsonBuffer_.AddChunk(",");
+    }
+    
+    jsonBuffer_.AddChunk(reinterpret_cast<const char*>(data) + 1, size - 2);  // remove leading and trailing []
+  }
 
   void DicomWebFormatter::HttpWriter::Send()
   {

--- a/Plugin/DicomWebFormatter.h	Mon Aug 21 15:16:23 2023 +0200
+++ b/Plugin/DicomWebFormatter.h	Mon Aug 21 16:33:27 2023 +0200
@@ -115,8 +115,11 @@
 
       void AddOrthancJson(const Json::Value& value);
 
-      void AddDicomWebSerializedJson(const void* data,
-                                     size_t size);
+      void AddDicomWebInstanceSerializedJson(const void* data,
+                                             size_t size);
+
+      void AddDicomWebSeriesSerializedJson(const void* data,
+                                           size_t size);
 
       void Send();
 

--- a/Plugin/WadoRs.cpp	Mon Aug 21 15:16:23 2023 +0200
+++ b/Plugin/WadoRs.cpp	Mon Aug 21 16:33:27 2023 +0200
@@ -882,7 +882,7 @@
   {
     if (buffer.RestApiGet("/instances/" + orthancId + "/attachments/4444/data", false))
     {
-      writer.AddDicomWebSerializedJson(buffer.GetData(), buffer.GetSize());
+      writer.AddDicomWebInstanceSerializedJson(buffer.GetData(), buffer.GetSize());
     }
     else if (buffer.RestApiGet("/instances/" + orthancId + "/file", false))
     {
@@ -898,7 +898,7 @@
       }
 
       buffer.RestApiPut("/instances/" + orthancId + "/attachments/4444", dicomweb, false);
-      writer.AddDicomWebSerializedJson(dicomweb.c_str(), dicomweb.size());
+      writer.AddDicomWebInstanceSerializedJson(dicomweb.c_str(), dicomweb.size());
     }
   }
 #endif
@@ -1449,7 +1449,10 @@
 
     if (!OrthancPlugins::RestApiGetString(compressedSeriesMetadata, attachmentUrl + "/data", false))
     {
-      CacheSeriesMetadataInternal(serializedSeriesMetadata, writer, cache, studyInstanceUid, seriesInstanceUid, seriesOrthancId);
+      MainDicomTagsCache tmpCache;
+      OrthancPlugins::DicomWebFormatter::HttpWriter tmpWriter(NULL /* output */, false /* isXml */);  // we cache only the JSON format -> no need for an HttpOutput
+
+      CacheSeriesMetadataInternal(serializedSeriesMetadata, tmpWriter, tmpCache, studyInstanceUid, seriesInstanceUid, seriesOrthancId);
     }
     else
     {
@@ -1458,7 +1461,7 @@
     
     boost::replace_all(serializedSeriesMetadata, WADO_BASE_PLACEHOLDER, wadoBase);
 
-    writer.AddDicomWebSerializedJson(serializedSeriesMetadata.c_str(), serializedSeriesMetadata.size());
+    writer.AddDicomWebSeriesSerializedJson(serializedSeriesMetadata.c_str(), serializedSeriesMetadata.size());
   }
   else
   {