diff --git a/RestControllers/CallsController.php b/RestControllers/CallsController.php
index cdfc4f9..4c5ff7f 100644
--- a/RestControllers/CallsController.php
+++ b/RestControllers/CallsController.php
@@ -85,6 +85,50 @@ class CallsController {
 		return self::CallInformationToAPI($call);
 	}
 
+	/**
+	 * Respond to a call
+	 * 
+	 * @url POST /calls/respond
+	 */
+	public function respondToCall(){
+		user_login_required();
+
+		//Get target call ID
+		$call_id = $this->GetSafeCallIDFromRequest("call_id");
+
+		//Get target response
+		$accept = postBool("accept");
+
+		//Set user response to call
+		if(!components()->calls->setMemberResponse($call_id, userID, $accept))
+			Rest_fatal_error(500, "Could not set response of user to call!");
+		
+		return array(
+			"success" => "User response to call has been successfully set!"
+		);
+	}
+
+	/**
+	 * Get safely the ID of a call from the request
+	 * 
+	 * @param $name The name of the POST field containing call ID
+	 * @return int The ID of the call
+	 */
+	private function GetSafeCallIDFromRequest(string $name) : int {
+
+		//Get call ID
+		$call_id = postInt($name);
+
+		if($call_id < 1)
+			Rest_fatal_error(401, "Invalid call id !");
+		
+		//Check if the user belongs to the call or not
+		if(!components()->calls->doesUserBelongToCall($call_id, userID))
+			Rest_fatal_error(401, "You do not belong to this call!");
+		
+		return $call_id;
+	}
+
 	/**
 	 * Turn a CallsConfig object into an API entry
 	 * 
diff --git a/classes/components/CallsComponent.php b/classes/components/CallsComponent.php
index d8fc7b0..7e50800 100644
--- a/classes/components/CallsComponent.php
+++ b/classes/components/CallsComponent.php
@@ -220,6 +220,21 @@ class CallsComponents {
 
 	}
 
+	/**
+	 * Check out whether a user belongs to a call or not
+	 * 
+	 * @param $callID The ID of the target call
+	 * @param $userID The ID of the target user
+	 * @return bool TRUE if the user belongs to the call / FALSE else
+	 */
+	public function doesUserBelongToCall(int $callID, int $userID) : bool {
+		return db()->count(
+			self::CALLS_MEMBERS_TABLE,
+			"WHERE call_id = ? AND user_id = ?",
+			array($callID, $userID)
+		) > 0;
+	}
+
 	/**
 	 * Set the response of a member to a call
 	 *