diff --git a/observer/messages/collector.go b/observer/messages/collector.go
index ec43be6..19eefcf 100644
--- a/observer/messages/collector.go
+++ b/observer/messages/collector.go
@@ -1,11 +1,6 @@
 package messages
 
 const (
-	COLLECTOR_STARTED = "COLLECTOR_STARTED"
 	COLLECTED         = "COLLECTED"
 	COLLECTOR_STOPPED = "COLLECTOR_STOPPED"
-
-	ADD_SENSOR    = "ADD_SENSOR"
-	UPDATE_SENSOR = "UPDATE_SENSOR"
-	REMOVE_SENSOR = "REMOVE_SENSOR"
 )
diff --git a/observer/messages/commons.go b/observer/messages/commons.go
index 6ba4799..8b51dd6 100644
--- a/observer/messages/commons.go
+++ b/observer/messages/commons.go
@@ -1,5 +1,7 @@
 package messages
 
 const (
-	API_SERVER_INFO = "API_SERVER_INFO"
+	AGENT_STARTED      = "AGENT_STARTED"
+	AGENT_WILL_STOPPED = "AGENT_WILL_STOPPED"
+	AGENT_STOPPED      = "AGENT_STOPPED"
 )
diff --git a/observer/messages/data_sender.go b/observer/messages/data_sender.go
index 468c045..05331dc 100644
--- a/observer/messages/data_sender.go
+++ b/observer/messages/data_sender.go
@@ -1,3 +1,5 @@
 package messages
 
-const ()
+const (
+	DATA_SENDER_STOPPED = "DATA_SENDER_STOPPED"
+)
diff --git a/observer/messages/poller.go b/observer/messages/poller.go
index 27041da..fcc6031 100644
--- a/observer/messages/poller.go
+++ b/observer/messages/poller.go
@@ -1,9 +1,7 @@
 package messages
 
 const (
-	POLLER_STARTED = "POLLER_STARTED"
-	NEW_CONF_FOUND = "NEW_CONF_FOUND"
-	POLLER_STOPPED = "POLLER_STOPPED"
-
-	UPDATE_POLLING_INTERVAL = "UPDATE_POLLING_INTERVAL"
+	POLLER_STOPPED  = "POLLER_STOPPED"
+	ADD_SENSOR_0    = "ADD_SENSOR_0"
+	REMOVE_SENSOR_0 = "REMOVE_SENSOR_0"
 )