# ChannelService > The ChannelService encapsulates a WebSocket server running in Unity. ## Definition * **Type:** Class * **Namespace:** [UnityEditor.MPE](/engine/6000.5/script-reference/unityeditor/mpe.md) * **Assembly:** UnityEditor.CoreModule ```csharp public static class ChannelService ``` ## Remarks The ChannelService allows you to create new communication channels. A channel matches the route of the URL connecting to the ChannelService. For example, "127.0.0.1:9292/\\\" The ChannelService allows custom handlers to receive all messages on a specific channel. Unity does not start the ChannelService automatically. You must start it manually using [ChannelService.Start](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/start.md). Alternatively, you can use the following command line switch: --ump-channel-service-on-startup. ## Examples ```csharp using System; using System.Text; using UnityEditor.MPE; using UnityEditor; using UnityEngine; public static class ChannelCommunicationDocExample { [MenuItem("ChannelDoc/Step 1")] static void StartChannelService() { if (!ChannelService.IsRunning()) { ChannelService.Start(); } Debug.Log($"[Step1] ChannelService Running: {ChannelService.GetAddress()}:{ChannelService.GetPort()}"); } static int s_BinaryChannelId; static int s_StringChannelId; static Action s_DisconnectBinaryChannel; static Action s_DisconnectStringChannel; [MenuItem("ChannelDoc/Step 2")] static void SetupChannelService() { if (s_DisconnectBinaryChannel == null) { s_DisconnectBinaryChannel = ChannelService.GetOrCreateChannel("custom_binary_ping_pong", HandleChannelBinaryMessage); s_BinaryChannelId = ChannelService.ChannelNameToId("custom_binary_ping_pong"); } Debug.Log($"[Step2] Setup channel_custom_binary id: {s_BinaryChannelId}"); if (s_DisconnectStringChannel == null) { s_DisconnectStringChannel = ChannelService.GetOrCreateChannel("custom_ascii_ping_pong", HandleChannelStringMessage); s_StringChannelId = ChannelService.ChannelNameToId("custom_ascii_ping_pong"); } Debug.Log($"[Step2] Setup channel_custom_ascii id: {s_StringChannelId}"); } static void HandleChannelBinaryMessage(int connectionId, byte[] data) { var msg = ""; for (var i = 0; i < Math.Min(10, data.Length); ++i) { msg += data[i].ToString(); } Debug.Log($"Channel Handling binary from connection {connectionId} - {data.Length} bytes - {msg}"); // Client has sent a message (this is a ping) // Lets send back the same message (as a pong) ChannelService.Send(connectionId, data); } static void HandleChannelStringMessage(int connectionId, byte[] data) { // Client has sent a message (this is a ping) // Client expects string data. Encode the data and send it back as a string: var msgStr = Encoding.UTF8.GetString(data); Debug.Log($"Channel Handling string from connection {connectionId} - {msgStr}"); // Send back the same message (as a pong) ChannelService.Send(connectionId, msgStr); } static ChannelClient s_BinaryClient; static Action s_DisconnectBinaryClient; static ChannelClient s_StringClient; static Action s_DisconnectStringClient; [MenuItem("ChannelDoc/Step 3")] static void SetupChannelClient() { const bool autoTick = true; if (s_BinaryClient == null) { s_BinaryClient = ChannelClient.GetOrCreateClient("custom_binary_ping_pong"); s_BinaryClient.Start(autoTick); s_DisconnectBinaryClient = s_BinaryClient.RegisterMessageHandler(HandleClientBinaryMessage); } Debug.Log($"[Step3] Setup client for channel custom_binary_ping_pong. ClientId: {s_BinaryClient.clientId}"); if (s_StringClient == null) { s_StringClient = ChannelClient.GetOrCreateClient("custom_ascii_ping_pong"); s_StringClient.Start(autoTick); s_DisconnectStringClient = s_StringClient.RegisterMessageHandler(HandleClientStringMessage); } Debug.Log($"[Step3] Setup client for channel custom_ascii_ping_pong. ClientId: {s_StringClient.clientId}"); } static void HandleClientBinaryMessage(byte[] data) { Debug.Log($"Receiving pong binary data: {data} for clientId: {s_BinaryClient.clientId} with channelName: {s_BinaryClient.channelName}"); } static void HandleClientStringMessage(string data) { Debug.Log($"Receiving pong data: {data} for clientId: {s_StringClient.clientId} with channelName: {s_StringClient.channelName}"); } [MenuItem("ChannelDoc/Step 4")] static void ClientSendMessageToServer() { Debug.Log("[Step 4]: Clients are sending data!"); s_BinaryClient.Send(new byte[] { 0, 1, 2, 3, 4, 5, 6, 7 }); s_StringClient.Send("Hello world!"); } [MenuItem("ChannelDoc/Step 5")] static void CloseClients() { Debug.Log("[Step 5]: Closing clients"); s_DisconnectBinaryClient(); s_BinaryClient.Close(); s_DisconnectStringClient(); s_StringClient.Close(); } [MenuItem("ChannelDoc/Step 6")] static void CloseService() { Debug.Log("[Step 6]: Closing clients"); s_DisconnectBinaryChannel(); s_DisconnectStringChannel(); ChannelService.Stop(); } } /* When you execute the menu items one after the other, Unity prints the following messages to the Console window: [Step1] ChannelService Running: 127.0.0.1:64647 [Step2] Setup channel_custom_binary id: -1698345965 [Step2] Setup channel_custom_ascii id: -930064725 [Step3] Setup client for channel custom_binary_ping_pong. ClientId: -1698345965 [Step3] Setup client for channel custom_ascii_ping_pong. ClientId: -930064725 [Step 4]: Clients are sending data! Channel Handling binary from connection 1 - 8 bytes - 01234567 Channel Handling string from connection 2 - Hello world! Receiving pong binary data: System.Byte[] for clientId: -1698345965 with channelName: custom_binary_ping_pong Receiving pong data: Hello world! for clientId: -930064725 with channelName: custom_ascii_ping_pong [Step 5]: Closing clients [Step 6]: Closing clients */ ``` ## Static Methods | Method | Description | | ---------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [Broadcast](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/broadcast.md) | Sends a message to all of a specific channel's [ChannelClient](/engine/6000.5/script-reference/unityeditor/mpe/channelclient.md) connections. | | [BroadcastBinary](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/broadcastbinary.md) | Sends a message to all of a specific channel's [ChannelClient](/engine/6000.5/script-reference/unityeditor/mpe/channelclient.md) connections. | | [ChannelNameToId](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/channelnametoid.md) | Closes a specific channel and all connections to that channel. | | [CloseChannel](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/closechannel.md) | Closes a specific channel and all connections to that channel. | | [DispatchMessages](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/dispatchmessages.md) | Dispatches any messages that have been received since the last dispatch. This happens automatically every editor tick, but this method can be used to force dispatching to occur during thread-blocking operations. | | [GetAddress](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/getaddress.md) | Gets the address of the ChannelService. This is always a local address. For example, 127.0.0.1. | | [GetChannelClientList](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/getchannelclientlist.md) | Gets a list of all channel clients connected to the [ChannelService](/engine/6000.5/script-reference/unityeditor/mpe/channelservice.md). | | [GetChannelList](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/getchannellist.md) | Gets a list of channels open in the ChannelService. By default the ChannelService always has a "status" channel and an "events" channel. | | [GetOrCreateChannel](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/getorcreatechannel.md) | Gets or creates a new channel. | | [GetPort](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/getport.md) | Retrieves the port where the ChannelService runs. This port is chosen randomly when the ChannelService first starts. Alternatively you can specify the port from the command line, using the --ump-channel-service-port \\\ switch. | | [IsRunning](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/isrunning.md) | Checks whether the ChannelService is running and listening to new connections.. | | [RegisterMessageHandler](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/registermessagehandler.md) | Registers a handler to process all incoming messages on a specific channel. | | [Send](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/send.md) | Sends a message to a specific connection. The message can be binary or UTF8. | | [Start](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/start.md) | Starts the ChannelService. After you start the ChannelService it listens to connection at the URL provided by: \\\:\\\/\\\, for example, 127.0.0.1:9976/events. See [ChannelService.GetAddress](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/getaddress.md) and GetPort. | | [Stop](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/stop.md) | Stops the ChannelService from listening to connections, and closes any already established connections. | | [UnregisterMessageHandler](/engine/6000.5/script-reference/unityeditor/mpe/channelservice/unregistermessagehandler.md) | Unregisters a specific handler from a Channel. |