diff --git a/RestControllers/conversationsController.php b/RestControllers/conversationsController.php
index b761754..4215940 100644
--- a/RestControllers/conversationsController.php
+++ b/RestControllers/conversationsController.php
@@ -109,7 +109,7 @@ class conversationsController{
 			Rest_fatal_error(400, "Please specify a conversation ID !");
 		$conversationID = toInt($_POST["conversationID"]);
 
-		//Check if the user is a conversation moderator or not
+		//Check if the user belongs to the conversation
 		if(!CS::get()->components->conversations->userBelongsTo(userID, $conversationID))
 			Rest_fatal_error("401", "Specified user doesn't belongs to the conversation !");
 
@@ -210,4 +210,44 @@ class conversationsController{
 		//Success
 		return array("conversationsID" => $results); 
 	}
+
+	/**
+	 * Send a new message
+	 *
+	 * @url POST /conversations/sendMessage
+	 */
+	public function sendMessage(){
+		user_login_required();
+
+		//First, check a conversation ID was specified
+		if(!isset($_POST["conversationID"]))
+			Rest_fatal_errror(400, "Please speicify a conversation ID !");
+
+		//Extract conversation ID
+		$conversationID = toInt($_POST["conversationID"]);
+
+		//Check if the user belongs to the conversation
+		if(!CS::get()->components->conversations->userBelongsTo(userID, $conversationID))
+			Rest_fatal_error(401, "Specified user doesn't belongs to the conversation !");
+
+		//Check if informations were specified about the new message or not
+		if(!isset($_POST['message']) AND !isset($_POST['image']))
+			Rest_fatal_error(401, "Nothing to be sent with the new message !");
+		
+		//Else extract informations
+		$message = (isset($_POST['message']) ? $_POST['message'] : "");
+		$image = (isset($_POST['image']) ? $_POST['image'] : false);
+
+		//Check message validity
+		if(!check_string_before_insert($message) && !$image)
+			Rest_fatal_error(401, "Invalid message sending request !");
+
+		//Process images NOT IMPLEMENTED YET
+
+		//Insert the new message
+		if(!CS::get()->components->conversations->sendMessage(userID, $conversationID, $message))
+			Rest_fatal_error(500, "Couldn't send the message !");
+		
+		Rest_fatal_error("200", "All right now");
+	}
 }
\ No newline at end of file
diff --git a/classes/components/conversations.php b/classes/components/conversations.php
index 78e8f50..2b73209 100644
--- a/classes/components/conversations.php
+++ b/classes/components/conversations.php
@@ -411,6 +411,23 @@ class conversations {
 		return $conversationsID;
 	}
 
+	/**
+	 * Send a new message
+	 *
+	 * @param Integer $userID The ID of the user sending the message
+	 * @param Integer $conversationID The ID of the target conversation
+	 * @param String $message The message
+	 * @return Boolean True for a success
+	 */
+	 public function sendMessage($userID, $conversationID, $message){
+
+		//GUIDE LINE : this method act like a "controller" : it doesn't perform any database operation
+		//But it manage all operations (insert message; save image; inform other users; ...)
+
+		 //Success
+		 return true;
+	 }
+
 }
 
 //Register component
diff --git a/functions/requests.php b/functions/requests.php
index 6aef9fb..60c5fd4 100644
--- a/functions/requests.php
+++ b/functions/requests.php
@@ -64,4 +64,42 @@ function users_list_to_array($list) : array{
  */
 function toInt($input){
 	return floor($input*1);
+}
+
+/**
+ * Remove HTML markup codes (<, >)
+ *
+ * @param String $input The string to change
+ * @return String The updated string
+ */
+function removeHTMLnodes($input){
+	$output = str_replace("<", "&lt;", $input);
+	return str_replace(">", "&gt;", $output);
+}
+
+/**
+ * Check a string before inserting it
+ *
+ * @param String $string The string to check
+ * @return Boolean True if the string is valid / false else
+ */
+function check_string_before_insert($string){
+
+	//First, empty string are invalid
+	if($string == "")
+		return false;
+	
+	//Remove HTML tags before continuing
+	$string = str_replace(array("<", ">"), "", $string);
+
+	//Check string size
+	if(strlen($string)<5)
+		return false;
+
+	//Check if the string has at least three different characters
+	if(strlen(count_chars($string,3)) < 3)
+		return false; 
+	
+	//Success
+	return true;
 }
\ No newline at end of file
diff --git a/functions/strings.php b/functions/strings.php
index 0f8e3c2..cd67998 100644
--- a/functions/strings.php
+++ b/functions/strings.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * API specific methods
+ * Strings methods
  *
  * @author Pierre HUBERT
  */
@@ -22,4 +22,4 @@ function random_str($length, $keyspace = '0123456789abcdefghijklmnopqrstuvwxyzAB
         $str .= $keyspace[random_int(0, $max)];
     }
     return $str;
-}
+}
\ No newline at end of file