Index: CloudConnect/CloudConnectController.cpp
===================================================================
diff -u -re9aa2c82ccb8cb5662f05ed878d2f7b5ef9f4a65 -rfe8875710ffd0f7ecc8df54bb5dee1be3d28212b
--- CloudConnect/CloudConnectController.cpp	(.../CloudConnectController.cpp)	(revision e9aa2c82ccb8cb5662f05ed878d2f7b5ef9f4a65)
+++ CloudConnect/CloudConnectController.cpp	(.../CloudConnectController.cpp)	(revision fe8875710ffd0f7ecc8df54bb5dee1be3d28212b)
@@ -24,16 +24,25 @@
 #include <QString>
 #include <QTimer>
 
+// BEGIN: Mesg Stats
 #include <QList>
 #include <QLoggingCategory>
 #include <QSaveFile>
+// END: Mesg Stats
 
+// BEGIN: Protobuf capture
+#include <google/protobuf/descriptor.h>
+#include <google/protobuf/dynamic_message.h>
+#include <google/protobuf/util/json_util.h>
+// END: Protobuf capture
+
 #include "CloudConnectController.h"
 #include "LeahiMsgDefs.pb.h"
 #include "LeahiMsgProtoUtils.h"
 
 Q_LOGGING_CATEGORY(logConfig,       "config")
 Q_LOGGING_CATEGORY(logProto,        "proto")
+Q_LOGGING_CATEGORY(logProtoCapture, "proto.capture") // TODO: Protobuf capture
 Q_LOGGING_CATEGORY(logCanRouting,   "can.routing")
 Q_LOGGING_CATEGORY(logMqtt,         "mqtt")
 Q_LOGGING_CATEGORY(logMqttStats,    "mqtt.stats")
@@ -114,6 +123,13 @@
         return false;
     }
 
+    // BEGIN: Protobuf capture
+    config.beginGroup(QStringLiteral("Capture"));
+    _captureSerFile = new QFile(config.value("SerFile").toString(), this);
+    _captureJsonFile = new QFile(config.value("JsonFile").toString(), this);
+    config.endGroup();
+    // END: Protobuf capture
+
     return true;
 }
 
@@ -333,6 +349,9 @@
 
     QByteArray payload;
     if (leahi::canMessageToProtobufByteArray(QDateTime::currentDateTime(), msg, payload)) {
+        // TODO: Protobuf capture
+        // captureProtobuf(payload);
+
         qint32 pubId;
         if (_mqttClient.publish(mqttTopic(it->topic), payload, pubId)) {
             qCWarning(logMqtt).noquote() << QString("message[ msgId=0x%1 (%2), seq=%3 ], published (pubId=%4)")
@@ -532,6 +551,76 @@
     qCDebug(logProto).noquote() << QString::fromStdString(typeName) << ":" << Qt::endl << QString::fromStdString(json);
 }
 
+// BEGIN: Protobuf capture
+void CloudConnectController::captureProtobuf(const QByteArray &payload)
+{
+    static auto encodeVarint = [](quint32 value) -> QByteArray {
+        QByteArray out;
+        do {
+            quint8 byte = value & 0x7F;
+            value >>= 7;
+            if (value != 0) {
+                byte |= 0x80;   // more bytes follow
+            }
+            out.append(static_cast<char>(byte));
+        } while (value != 0);
+        return out;
+    };
+
+    if (_captureSerFile) {
+        if (_captureSerFile->open(QIODevice::WriteOnly | QIODevice::Append)) {
+            qCInfo(logProtoCapture).noquote() << QString("wrote to protobuf capture file %1 (sizes: length=%2, payload=%3)")
+                .arg(_captureSerFile->fileName())
+                .arg(_captureSerFile->write(encodeVarint(static_cast<quint32>(payload.size()))))
+                .arg(_captureSerFile->write(payload));
+            _captureSerFile->flush();
+            _captureSerFile->close();
+        }
+        else {
+            qCCritical(logProtoCapture).noquote() << QString("cannot open capture ser file %1").arg(_captureSerFile->fileName());
+        }
+    }
+    else {
+        qCCritical(logProtoCapture).noquote() << QString("capture ser file is null");
+    }
+
+    if (_captureJsonFile) {
+        if (_captureJsonFile->open(QIODevice::WriteOnly | QIODevice::Append | QIODevice::Text)) {
+            leahi::messages::Envelope envelope;
+            if (envelope.ParseFromArray(payload.constData(), payload.size())) {
+                const leahi::messages::Header &header = envelope.header();
+                const google::protobuf::Descriptor *desc =
+                    google::protobuf::DescriptorPool::generated_pool()->FindMessageTypeByName(
+                        leahi::msgIdToProtoName(static_cast<quint16>(header.msgid())));
+                if (desc) {
+                    google::protobuf::DynamicMessageFactory factory;
+                    std::unique_ptr<google::protobuf::Message> body(factory.GetPrototype(desc)->New());
+                    if (body->ParseFromArray(payload.constData(), payload.size())) {
+                        std::string json;
+                        google::protobuf::util::JsonPrintOptions opts;
+                        opts.add_whitespace = true;
+                        opts.always_print_primitive_fields = true;
+                        google::protobuf::util::MessageToJsonString(*body, &json, opts);
+                        QString jsonStr = QString::fromStdString(json);
+                        qCInfo(logProtoCapture).noquote() << QString("wrote to capture json file %1 (size: json=%2)")
+                            .arg(_captureJsonFile->fileName())
+                            .arg(_captureJsonFile->write(jsonStr.toLatin1()));
+                        _captureJsonFile->flush();
+                        _captureJsonFile->close();
+                    }
+                }
+            }
+        }
+        else {
+            qCCritical(logProtoCapture).noquote() << QString("cannot open capture json file %1").arg(_captureJsonFile->fileName());
+        }
+    }
+    else {
+        qCCritical(logProtoCapture).noquote() << QString("capture json file is null");
+    }
+}
+// END: Protobuf capture
+
 // BEGIN: Mesg Stats
 QString CloudConnectController::canStats(Can::MsgId msgId, qint64 sinceLastUs) const
 {