diff --git a/src/handlers/teamspeak/dataHandler.ts b/src/handlers/teamspeak/dataHandler.ts
new file mode 100644
index 0000000..a268cd7
--- /dev/null
+++ b/src/handlers/teamspeak/dataHandler.ts
@@ -0,0 +1,204 @@
+import { IConnection, IChannel, IClient } from "interfaces/teamspeak";
+
+
+/**
+ * Handles data received from TS5 client (list of connections, channels and clients)
+ * Updates the states of App.tsx
+ */
+export class TS5DataHandler {
+  // Local lists of connections, channels and clients
+  // These lists are used to keep track of the data, independent of the App.tsx state
+  localConnections: IConnection[];
+  localChannels: IChannel[];
+  localClients: IClient[];
+
+  // State setters for App.tsx
+  setConnections: React.Dispatch<React.SetStateAction<IConnection[]>>;
+  setChannels: React.Dispatch<React.SetStateAction<IChannel[]>>;
+  setClients: React.Dispatch<React.SetStateAction<IClient[]>>;
+
+  constructor(
+    // State setters for App.tsx
+    setConnections: React.Dispatch<React.SetStateAction<IConnection[]>>,
+    setChannels: React.Dispatch<React.SetStateAction<IChannel[]>>,
+    setClients: React.Dispatch<React.SetStateAction<IClient[]>>
+  ) {
+    this.setConnections = setConnections;
+    this.setChannels = setChannels;
+    this.setClients = setClients;
+
+    this.localConnections = [];
+    this.localChannels = [];
+    this.localClients = [];
+  }
+
+  // Update App.tsx states
+  private updateConnectionsState() {
+    this.setConnections([...this.localConnections]);
+  }
+
+  private updateChannelsState() {
+    this.setChannels([...this.localChannels]);
+  }
+
+  private updateClientsState() {
+    this.setClients([...this.localClients]);
+  }
+
+  // Clear all data
+  clearAll() {
+    this.localConnections = [];
+    this.localChannels = [];
+    this.localClients = [];
+
+    this.updateConnectionsState();
+    this.updateChannelsState();
+    this.updateClientsState();
+  }
+
+  // Add data to local lists and update states
+  addConnection(connection: IConnection) {
+    console.log("Adding connection...", connection)
+
+    const existingConnection: IConnection | undefined = this.localConnections.find((localConnection: IConnection) => localConnection.id === connection.id);
+
+    if (existingConnection == undefined) {
+      this.localConnections.push(connection);
+      this.updateConnectionsState();
+      console.log("Connection added")
+    } else {
+      console.log("Connection already exists")
+    }
+  }
+
+  addChannel(channel: IChannel) {
+    console.log("Adding channel...", channel)
+    const existingChannel: IChannel | undefined = this.localChannels.find((localChannel: IChannel) => localChannel.id === channel.id && localChannel.connection.id === channel.connection.id);
+
+    if (existingChannel == undefined) {
+      this.localChannels.push(channel);
+      this.updateChannelsState();
+      console.log("Channel added")
+    } else {
+      console.log("Channel already exists")
+    }
+  }
+
+  addClient(client: IClient) {
+    console.log("Adding client...", client)
+    const existingClient: IClient | undefined = this.localClients.find((localClient: IClient) => localClient.id === client.id && localClient.channel?.connection.id === client.channel?.connection.id);
+
+    if (existingClient == undefined) {
+      this.localClients.push(client);
+      this.updateClientsState();
+      console.log("Client added")
+    } else {
+      console.log("Client already exists")
+    }
+  }
+
+  // Update data in local lists and update states
+  updateConnection(connection: IConnection) {
+    console.log("Updating connection...", connection)
+    const existingConnection: IConnection | undefined = this.localConnections.find((localConnection: IConnection) => localConnection.id === connection.id);
+
+    if (existingConnection !== undefined) {
+      this.localConnections[this.localConnections.indexOf(existingConnection)] = connection;
+      this.updateConnectionsState();
+      console.log("Connection updated")
+    } else {
+      console.log("Connection does not exist")
+    }
+  }
+
+  updateChannel(channel: IChannel) {
+    console.log("Updating channel...", channel)
+    const existingChannel: IChannel | undefined = this.localChannels.find((localChannel: IChannel) => localChannel.id === channel.id && localChannel.connection.id === channel.connection.id);
+
+    if (existingChannel !== undefined) {
+      this.localChannels[this.localChannels.indexOf(existingChannel)] = channel;
+      this.updateChannelsState();
+      console.log("Channel updated")
+    } else {
+      console.log("Channel does not exist")
+    }
+  }
+
+  updateClient(client: IClient) {
+    console.log("Updating client...", client)
+    const existingClient: IClient | undefined = this.localClients.find((localClient: IClient) => localClient.id === client.id && localClient.channel?.connection.id === client.channel?.connection.id);
+
+    if (existingClient !== undefined) {
+      this.localClients[this.localClients.indexOf(existingClient)] = client;
+      this.updateClientsState();
+      console.log("Client updated")
+    } else {
+      console.log("Client does not exist")
+    }
+  }
+
+  // Remove data from local lists and update states
+  removeConnection(connection: IConnection) {
+    console.log("Removing connection...", connection)
+    const existingConnection: IConnection | undefined = this.localConnections.find((localConnection: IConnection) => localConnection.id === connection.id);
+
+    if (existingConnection !== undefined) {
+      this.localConnections.splice(this.localConnections.indexOf(existingConnection), 1);
+
+      // Remove all channels and clients associated with the connection
+      this.localChannels = this.localChannels.filter((localChannel: IChannel) => localChannel.connection.id !== connection.id);
+      this.localClients = this.localClients.filter((localClient: IClient) => localClient.channel?.connection.id !== connection.id);
+
+      this.updateChannelsState();
+      this.updateClientsState();
+      this.updateConnectionsState();
+      console.log("Connection removed")
+    } else {
+      console.log("Connection does not exist")
+    }
+  }
+
+  removeChannel(channel: IChannel) {
+    console.log("Removing channel...", channel)
+    const existingChannel: IChannel | undefined = this.localChannels.find((localChannel: IChannel) => localChannel.id === channel.id && localChannel.connection.id === channel.connection.id);
+
+    if (existingChannel !== undefined) {
+      this.localChannels.splice(this.localChannels.indexOf(existingChannel), 1);
+
+      // Remove all clients associated with the channel
+      this.localClients = this.localClients.filter((localClient: IClient) => localClient.channel?.id !== channel.id);
+
+      this.updateClientsState();
+      this.updateChannelsState();
+      console.log("Channel removed")
+    } else {
+      console.log("Channel does not exist")
+    }
+  }
+
+  removeClient(client: IClient) {
+    console.log("Removing client...", client)
+    const existingClient: IClient | undefined = this.localClients.find((localClient: IClient) => localClient.id === client.id && localClient.channel?.connection.id === client.channel?.connection.id);
+
+    if (existingClient !== undefined) {
+      this.localClients.splice(this.localClients.indexOf(existingClient), 1);
+      this.updateClientsState();
+      console.log("Client removed")
+    } else {
+      console.log("Client does not exist")
+    }
+  }
+
+  // Helper functions
+  getConnectionById(id: number): IConnection | undefined {
+    return this.localConnections.find((connection: IConnection) => connection.id === id);
+  }
+
+  getChannelById(id: number, connectionId: number): IChannel | undefined {
+    return this.localChannels.find((channel: IChannel) => channel.id === id && channel.connection?.id === connectionId);
+  }
+
+  getClientById(id: number, connectionId: number): IClient | undefined {
+    return this.localClients.find((client: IClient) => client.id === id && client.channel?.connection.id === connectionId);
+  }
+}
\ No newline at end of file