diff --git a/audio/river/Interface.cpp b/audio/river/Interface.cpp
index 8e25c70..d84cd0f 100644
--- a/audio/river/Interface.cpp
+++ b/audio/river/Interface.cpp
@@ -33,7 +33,7 @@ bool audio::river::Interface::init(float _freq,
 	m_node = _node;
 	m_config = _config;
 	m_mode = audio::river::modeInterface_unknow;
-	std::string type = m_config.getStringValue("io", "error");
+	std::string type = m_config["io"].toString().get("error");
 	static int32_t uid=0;
 	m_name = _node->getName() + "__" + (_node->isInput()==true?"input":"output") + "__" + type + "__" + etk::to_string(uid++);
 	if (type == "output") {
diff --git a/audio/river/Manager.cpp b/audio/river/Manager.cpp
index 4ce15ad..0dad101 100644
--- a/audio/river/Manager.cpp
+++ b/audio/river/Manager.cpp
@@ -141,10 +141,10 @@ bool audio::river::Manager::getMute(const std::string& _volumeName) const {
 }
 
 std::shared_ptr<audio::river::Interface> audio::river::Manager::createOutput(float _freq,
-                                                                               const std::vector<audio::channel>& _map,
-                                                                               audio::format _format,
-                                                                               const std::string& _streamName,
-                                                                               const std::string& _options) {
+                                                                             const std::vector<audio::channel>& _map,
+                                                                             audio::format _format,
+                                                                             const std::string& _streamName,
+                                                                             const std::string& _options) {
 	// get global hardware interface:
 	std::shared_ptr<audio::river::io::Manager> manager = audio::river::io::Manager::getInstance();
 	if (manager == nullptr) {
@@ -164,7 +164,7 @@ std::shared_ptr<audio::river::Interface> audio::river::Manager::createOutput(flo
 	// create user iterface:
 	std::shared_ptr<audio::river::Interface> interface;
 	ejson::Object tmpOption = ejson::Object(_options);
-	tmpOption.addString("io", "output");
+	tmpOption.add("io", ejson::String("output"));
 	interface = audio::river::Interface::create(_freq, _map, _format, node, tmpOption);
 	// store it in a list (needed to apply some parameters).
 	m_listOpenInterface.push_back(interface);
@@ -195,7 +195,7 @@ std::shared_ptr<audio::river::Interface> audio::river::Manager::createInput(floa
 	// create user iterface:
 	std::shared_ptr<audio::river::Interface> interface;
 	ejson::Object tmpOption = ejson::Object(_options);
-	tmpOption.addString("io", "input");
+	tmpOption.add("io", ejson::String("input"));
 	interface = audio::river::Interface::create(_freq, _map, _format, node, tmpOption);
 	// store it in a list (needed to apply some parameters).
 	m_listOpenInterface.push_back(interface);
@@ -227,7 +227,7 @@ std::shared_ptr<audio::river::Interface> audio::river::Manager::createFeedback(f
 	// create user iterface:
 	std::shared_ptr<audio::river::Interface> interface;
 	ejson::Object tmpOption = ejson::Object(_options);
-	tmpOption.addString("io", "feedback");
+	tmpOption.add("io", ejson::String("feedback"));
 	interface = audio::river::Interface::create(_freq, _map, _format, node, tmpOption);
 	// store it in a list (needed to apply some parameters).
 	m_listOpenInterface.push_back(interface);
diff --git a/audio/river/io/Group.cpp b/audio/river/io/Group.cpp
index b49c5e7..55d73ea 100644
--- a/audio/river/io/Group.cpp
+++ b/audio/river/io/Group.cpp
@@ -22,11 +22,11 @@ void audio::river::io::Group::createFrom(const ejson::Document& _obj, const std:
 		if (tmpObject.exist() == false) {
 			continue;
 		}
-		std::string groupName = tmpObject.getStringValue("group", "");
+		std::string groupName = tmpObject["group"].toString().get();
 		if (groupName == _name) {
 			RIVER_INFO("Add element in Group[" << _name << "]: " << _obj.getKey(iii));
 			// get type : io
-			std::string ioType = tmpObject.getStringValue("io", "error");
+			std::string ioType = tmpObject["io"].toString().get("error");
 			#ifdef AUDIO_RIVER_BUILD_ORCHESTRA
 				if (    ioType == "input"
 				     || ioType == "output") {
diff --git a/audio/river/io/Manager.cpp b/audio/river/io/Manager.cpp
index fb03640..e9ea697 100644
--- a/audio/river/io/Manager.cpp
+++ b/audio/river/io/Manager.cpp
@@ -111,7 +111,7 @@ std::vector<std::string> audio::river::io::Manager::getListStreamInput() {
 	for (auto &it : keys) {
 		const ejson::Object tmppp = m_config[it].toObject();
 		if (tmppp.exist() == true) {
-			std::string type = tmppp.getStringValue("io", "error");
+			std::string type = tmppp["io"].toString().get("error");
 			if (    type == "input"
 			     || type == "PAinput") {
 				output.push_back(it);
@@ -128,7 +128,7 @@ std::vector<std::string> audio::river::io::Manager::getListStreamOutput() {
 	for (auto &it : keys) {
 		const ejson::Object tmppp = m_config[it].toObject();
 		if (tmppp.exist() == true) {
-			std::string type = tmppp.getStringValue("io", "error");
+			std::string type = tmppp["io"].toString().get("error");
 			if (    type == "output"
 			     || type == "PAoutput") {
 				output.push_back(it);
@@ -145,7 +145,7 @@ std::vector<std::string> audio::river::io::Manager::getListStreamVirtual() {
 	for (auto &it : keys) {
 		const ejson::Object tmppp = m_config[it].toObject();
 		if (tmppp.exist() == true) {
-			std::string type = tmppp.getStringValue("io", "error");
+			std::string type = tmppp["io"].toString().get("error");
 			if (    type != "input"
 			     && type != "PAinput"
 			     && type != "output"
@@ -165,7 +165,7 @@ std::vector<std::string> audio::river::io::Manager::getListStream() {
 	for (auto &it : keys) {
 		const ejson::Object tmppp = m_config[it].toObject();
 		if (tmppp.exist() == true) {
-			std::string type = tmppp.getStringValue("io", "error");
+			std::string type = tmppp["io"].toString().get("error");
 			if (type != "error") {
 				output.push_back(it);
 			}
@@ -205,9 +205,9 @@ std::shared_ptr<audio::river::io::Node> audio::river::io::Manager::getNode(const
 	const ejson::Object tmpObject = m_config[_name].toObject();
 	if (tmpObject.exist() == true) {
 		//Check if it is in a group:
-		std::string groupName = tmpObject.getStringValue("group", "");
+		std::string groupName = tmpObject["group"].toString().get();
 		// get type : io
-		std::string ioType = tmpObject.getStringValue("io", "error");
+		std::string ioType = tmpObject["io"].toString().get("error");
 		if (    groupName != ""
 		     && (    ioType == "input"
 		          || ioType == "output"
diff --git a/audio/river/io/Node.cpp b/audio/river/io/Node.cpp
index 6b98c6c..ec18863 100644
--- a/audio/river/io/Node.cpp
+++ b/audio/river/io/Node.cpp
@@ -34,7 +34,7 @@ audio::river::io::Node::Node(const std::string& _name, const ejson::Object& _con
 		# muxer/demuxer format type (int8-on-int16, int16-on-int32, int24-on-int32, int32-on-int64, float)
 		mux-demux-type:"int16_on_int32", 
 	*/
-	std::string interfaceType = m_config.getStringValue("io");
+	std::string interfaceType = m_config["io"].toString().get();
 	RIVER_INFO("interfaceType=" << interfaceType);
 	if (    interfaceType == "input"
 	     || interfaceType == "PAinput"
@@ -45,12 +45,12 @@ audio::river::io::Node::Node(const std::string& _name, const ejson::Object& _con
 		m_isInput = false;
 	}
 	
-	int32_t frequency = m_config.getNumberValue("frequency", 1);
+	int32_t frequency = m_config["frequency"].toNumber().get(1);
 	// Get audio format type:
-	std::string type = m_config.getStringValue("type", "int16");
+	std::string type = m_config["type"].toString().get("int16");
 	enum audio::format formatType = audio::getFormatFromString(type);
 	// Get volume stage :
-	std::string volumeName = m_config.getStringValue("volume-name", "");
+	std::string volumeName = m_config["volume-name"].toString().get();
 	if (volumeName != "") {
 		RIVER_INFO("add node volume stage : '" << volumeName << "'");
 		// use global manager for volume ...
@@ -75,9 +75,9 @@ audio::river::io::Node::Node(const std::string& _name, const ejson::Object& _con
 	
 	std::string muxerDemuxerConfig;
 	if (m_isInput == true) {
-		muxerDemuxerConfig = m_config.getStringValue("mux-demux-type", "int16");
+		muxerDemuxerConfig = m_config["mux-demux-type"].toString().get("int16");
 	} else {
-		muxerDemuxerConfig = m_config.getStringValue("mux-demux-type", "int16-on-int32");
+		muxerDemuxerConfig = m_config["mux-demux-type"].toString().get("int16-on-int32");
 	}
 	enum audio::format muxerFormatType = audio::getFormatFromString(muxerDemuxerConfig);
 	if (m_isInput == true) {
diff --git a/audio/river/io/NodeAEC.cpp b/audio/river/io/NodeAEC.cpp
index eb8f17e..f5c8d8e 100644
--- a/audio/river/io/NodeAEC.cpp
+++ b/audio/river/io/NodeAEC.cpp
@@ -28,11 +28,11 @@ std::shared_ptr<audio::river::Interface> audio::river::io::NodeAEC::createInput(
 		RIVER_ERROR("can not open a non existance virtual interface: '" << _objectName << "' not present in : " << m_config.getKeys());
 		return std::shared_ptr<audio::river::Interface>();
 	}
-	std::string streamName = tmppp.getStringValue("map-on", "error");
+	std::string streamName = tmppp["map-on"].toString().get("error");
 	
-	m_nbChunk = m_config.getNumberValue("nb-chunk", 1024);
+	m_nbChunk = m_config["nb-chunk"].toNumber().get(1024);
 	// check if it is an Output:
-	std::string type = tmppp.getStringValue("io", "error");
+	std::string type = tmppp["io"].toString().get("error");
 	if (    type != "input"
 	     && type != "feedback") {
 		RIVER_ERROR("can not open in output a virtual interface: '" << streamName << "' configured has : " << type);
diff --git a/audio/river/io/NodeMuxer.cpp b/audio/river/io/NodeMuxer.cpp
index 7612c08..08d10cd 100644
--- a/audio/river/io/NodeMuxer.cpp
+++ b/audio/river/io/NodeMuxer.cpp
@@ -28,11 +28,11 @@ std::shared_ptr<audio::river::Interface> audio::river::io::NodeMuxer::createInpu
 		RIVER_ERROR("can not open a non existance virtual interface: '" << _objectName << "' not present in : " << m_config.getKeys());
 		return std::shared_ptr<audio::river::Interface>();
 	}
-	std::string streamName = tmppp.getStringValue("map-on", "error");
+	std::string streamName = tmppp["map-on"].toString().get("error");
 	
 	
 	// check if it is an Output:
-	std::string type = tmppp.getStringValue("io", "error");
+	std::string type = tmppp["io"].toString().get("error");
 	if (    type != "input"
 	     && type != "feedback") {
 		RIVER_ERROR("can not open in output a virtual interface: '" << streamName << "' configured has : " << type);
diff --git a/audio/river/io/NodeOrchestra.cpp b/audio/river/io/NodeOrchestra.cpp
index 469ead2..43547e2 100644
--- a/audio/river/io/NodeOrchestra.cpp
+++ b/audio/river/io/NodeOrchestra.cpp
@@ -58,19 +58,19 @@ audio::river::io::NodeOrchestra::NodeOrchestra(const std::string& _name, const e
 	if (tmpObject.exist() == false) {
 		RIVER_WARNING("missing node : 'map-on' ==> auto map : 'auto:default'");
 	} else {
-		typeInterface = tmpObject.getStringValue("interface", audio::orchestra::type_undefined);
+		typeInterface = tmpObject["interface"].toString().get(audio::orchestra::type_undefined);
 		if (typeInterface == "auto") {
 			typeInterface = audio::orchestra::type_undefined;
 		}
-		streamName = tmpObject.getStringValue("name", "default");
+		streamName = tmpObject["name"].toString().get("default");
 	}
-	int32_t nbChunk = m_config.getNumberValue("nb-chunk", 1024);
+	int32_t nbChunk = m_config["nb-chunk"].toNumber().get(1024);
 	
 	// intanciate specific API ...
 	m_interface.instanciate(typeInterface);
 	m_interface.setName(_name);
 	// TODO : Check return ...
-	std::string type = m_config.getStringValue("type", "int16");
+	std::string type = m_config["type"].toString().get("int16");
 	if (streamName == "") {
 		streamName = "default";
 	}
@@ -189,7 +189,7 @@ audio::river::io::NodeOrchestra::NodeOrchestra(const std::string& _name, const e
 		RIVER_CRITICAL("Can not open hardware device with more channel (" << params.nChannels << ") that is autorized by hardware (" << m_info.channels.size() << ").");
 	}
 	audio::orchestra::StreamOptions option;
-	etk::from_string(option.mode, tmpObject.getStringValue("timestamp-mode", "soft"));
+	etk::from_string(option.mode, tmpObject["timestamp-mode"].toString().get("soft"));
 	
 	RIVER_DEBUG("interfaceFormat=" << interfaceFormat);
 	RIVER_DEBUG("hardwareFormat=" << hardwareFormat);