diff --git a/lib/session/StreamingMsgPackEncoder.h b/lib/session/StreamingMsgPackEncoder.h
index efef8cd..9b42421 100644
--- a/lib/session/StreamingMsgPackEncoder.h
+++ b/lib/session/StreamingMsgPackEncoder.h
@@ -15,7 +15,6 @@ const char TypeToMsgPackCode<int8_t>::CODE  = '\xd0';
 const char TypeToMsgPackCode<int16_t>::CODE = '\xd1';
 const char TypeToMsgPackCode<int32_t>::CODE = '\xd2';
 
-
 template<typename Writer>
 class StreamingMsgPackEncoder
 {
@@ -125,3 +124,36 @@ private:
     uint32_t contentLength;
     bool sizeCountMode;
 };
+
+
+
+template<typename Writer>
+class ChunkedStreamingMsgPackEncoder
+{
+public:
+    ChunkedStreamingMsgPackEncoder(Writer * writer_, uint32_t offset, uint32_t maxSize)
+        : encoder_(writer_), offset_(offset), maxSize_(maxSize), sent_(0)
+    {}
+
+    void sendMap16(byte size) {
+        // check if it fits, using separate object
+        encoder_.setSizeCountMode(true);
+    }
+
+    void sendString255(PGM_P s) {
+
+    }
+
+    template<typename T>
+    void sendInt(T value) {
+
+    }
+
+
+
+private:
+    StreamingMsgPackEncoder<Writer> encoder_;
+    uint32_t offset_;
+    uint32_t maxSize_;
+    uint32_t sent_;
+};
diff --git a/src/firmware_main.cpp b/src/firmware_main.cpp
index a6a5922..46a50ba 100644
--- a/src/firmware_main.cpp
+++ b/src/firmware_main.cpp
@@ -54,7 +54,10 @@ void httpSetup(SessionManager<Session_T> * sessionManager)
         sessionManager->stopMeasurements();
     });
     server.on("/api/session/data", HTTP_GET, [sessionManager](AsyncWebServerRequest * req) {
-        //TODO
+        StreamingMsgPackEncoder<HttpWriterAdaptor> encoder(&adaptor);
+
+        req->send_P(200, "application/x-msgpack", const uint8_t * content, size_t len)
+
     });