diff --git a/src/instance_storage.cr b/src/instance_storage.cr
new file mode 100644
index 0000000..a066d56
--- /dev/null
+++ b/src/instance_storage.cr
@@ -0,0 +1,20 @@
+# Link between fd and TCPSocket, WebSocket and IPC::Connection instances.
+class InstanceStorage
+	property is_json : Hash(Int32, Bool)
+	property fd_to_websocket : Hash(Int32, WebSocket)
+
+	def initialize
+		# fdlist_client = [] of TCPSocket
+		@is_json = Hash(Int32,Bool).new
+		@fd_to_websocket = Hash(Int32, WebSocket).new
+	end
+
+	def remove_fd (fdclient : Int32)
+		puts "#{CBLUE}closing the client:#{CRESET} #{fdclient}"
+		# 1. remove the client and the service from is_json
+		@is_json.select! do |fd,v| fd != fdclient end
+
+		# 2. remove the client from fd_to_websocket
+		@fd_to_websocket.select! do |fd, ws| fd != fdclient end
+	end
+end