diff --git a/lutinMacro_zeus.py b/lutinMacro_zeus.py
index 69aba65..347f0be 100644
--- a/lutinMacro_zeus.py
+++ b/lutinMacro_zeus.py
@@ -731,6 +731,10 @@ class ServiceDefinition:
 		out += space + "		m_obj = _srv;\n"
 		out += space + "		return *this;\n"
 		out += space + "	}\n"
+		out += space + "	const Proxy" + self.name[-1] + "& operator= (const Proxy" + self.name[-1] + "& _obj) {\n"
+		out += space + "		m_obj = _obj.m_obj;\n"
+		out += space + "		return *this;\n"
+		out += space + "	}\n"
 		out += space + "	~Proxy" + self.name[-1] + "() = default;\n"
 		out += space + "	Proxy" + self.name[-1] + "()"
 		if len(self.attributes) != 0:
diff --git a/zeus/Future.hpp b/zeus/Future.hpp
index 78094bb..aeda887 100644
--- a/zeus/Future.hpp
+++ b/zeus/Future.hpp
@@ -62,6 +62,40 @@ namespace zeus {
 				zeus::FutureBase::waitUntil(_endTime);
 				return *this;
 			}
+			using ObserverFut = std::function<bool(zeus::Future<ZEUS_RETURN>)>; //!< Define an Observer: function pointer for the local specific Future
+			/**
+			 * @brief Attach callback on all return type of value
+			 * @param[in] _callback Handle on the function to call in all case
+			 */
+			Future<ZEUS_RETURN>& andAll(ObserverFut _callback) {
+				zeus::FutureBase::andAll(
+				    [=](zeus::FutureBase _fut) {
+				    	return _callback(zeus::Future<ZEUS_RETURN>(_fut));
+				    });
+				return *this;
+			}
+			/**
+			 * @brief Attach callback on a specific return action (SUCESS)
+			 * @param[in] _callback Handle on the function to call in case of sucess on the call
+			 */
+			Future<ZEUS_RETURN>& andThen(ObserverFut _callback) {
+				zeus::FutureBase::andThen(
+				    [=](zeus::FutureBase _fut) {
+				    	return _callback(zeus::Future<ZEUS_RETURN>(_fut));
+				    });
+				return *this;
+			}
+			/**
+			 * @brief Attach callback on a specific return action (ERROR)
+			 * @param[in] _callback Handle on the function to call in case of error on the call
+			 */
+			Future<ZEUS_RETURN>& andElse(ObserverFut _callback) {
+				zeus::FutureBase::andElse(
+				    [=](zeus::FutureBase _fut) {
+				    	return _callback(zeus::Future<ZEUS_RETURN>(_fut));
+				    });
+				return *this;
+			}
 	};
 	/**
 	 * @brief future template to cast type in a void methode (fallback)
@@ -110,5 +144,39 @@ namespace zeus {
 				zeus::FutureBase::waitUntil(_endTime);
 				return *this;
 			}
+			using ObserverFut = std::function<bool(zeus::Future<void>)>; //!< Define an Observer: function pointer for the local specific Future
+			/**
+			 * @brief Attach callback on all return type of value
+			 * @param[in] _callback Handle on the function to call in all case
+			 */
+			Future<void>& andAll(ObserverFut _callback) {
+				zeus::FutureBase::andAll(
+				    [=](zeus::FutureBase _fut) {
+				    	return _callback(zeus::Future<void>(_fut));
+				    });
+				return *this;
+			}
+			/**
+			 * @brief Attach callback on a specific return action (SUCESS)
+			 * @param[in] _callback Handle on the function to call in case of sucess on the call
+			 */
+			Future<void>& andThen(ObserverFut _callback) {
+				zeus::FutureBase::andThen(
+				    [=](zeus::FutureBase _fut) {
+				    	return _callback(zeus::Future<void>(_fut));
+				    });
+				return *this;
+			}
+			/**
+			 * @brief Attach callback on a specific return action (ERROR)
+			 * @param[in] _callback Handle on the function to call in case of error on the call
+			 */
+			Future<void>& andElse(ObserverFut _callback) {
+				zeus::FutureBase::andElse(
+				    [=](zeus::FutureBase _fut) {
+				    	return _callback(zeus::Future<void>(_fut));
+				    });
+				return *this;
+			}
 	};
 }
diff --git a/zeus/message/Answer.cpp b/zeus/message/Answer.cpp
index 0ec74e6..0ffffce 100644
--- a/zeus/message/Answer.cpp
+++ b/zeus/message/Answer.cpp
@@ -40,6 +40,7 @@ void zeus::message::Answer::addError(const std::string& _value, const std::strin
 }
 
 bool zeus::message::Answer::writeOn(enet::WebSocket& _interface) {
+	std::unique_lock<std::mutex> lock = _interface.getScopeLock();
 	zeus::Message::writeOn(_interface);
 	_interface.writeData((uint8_t*)m_errorType.c_str(), m_errorType.size() + 1);
 	if (m_errorType.size() != 0) {
diff --git a/zeus/message/Call.cpp b/zeus/message/Call.cpp
index 9a051c2..3e998b4 100644
--- a/zeus/message/Call.cpp
+++ b/zeus/message/Call.cpp
@@ -35,6 +35,7 @@ void zeus::message::Call::setCall(const std::string& _value) {
 }
 
 bool zeus::message::Call::writeOn(enet::WebSocket& _interface) {
+	std::unique_lock<std::mutex> lock = _interface.getScopeLock();
 	zeus::Message::writeOn(_interface);
 	_interface.writeData((uint8_t*)m_callName.c_str(), m_callName.size() + 1);
 	return message::Parameter::writeOn(_interface);