> ## Documentation Index > Fetch the complete documentation index at: https://cometchat-22654f5b-docs-angular-v5-docs-update.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Real-Time Events > Listen for incoming messages, presence changes, typing indicators, receipts, group events, and connection state. The `UCometChatSubsystem` exposes 40+ multicast delegates organized by listener type. All delegates fire on the **Game Thread**, so you can safely update UI directly. ### Event Flow ```mermaid theme={null} flowchart LR A["CometChat Cloud"] -.->|"WebSocket"| B["C++ SDK"] B --> C["Subsystem Delegate"] C --> D["Your Blueprint / C++ handler"] style A fill:#555,stroke:#999,color:#ccc style B fill:#333,stroke:#666,color:#fff style C fill:#444,stroke:#888,color:#fff style D fill:#333,stroke:#666,color:#fff ``` **Bind delegates before calling Login.** Events that arrive between Login completing and your bindings being set up will be missed. *** ## Binding Delegates 1. Get a reference to the **CometChat Subsystem** 2. Drag off the Subsystem pin and search for the delegate name (e.g., **On Text Message Received**) 3. Select **Bind Event** to wire it to a custom event node 4. The custom event automatically gets the correct parameter type ```cpp theme={null} void AMyActor::BeginPlay() { Super::BeginPlay(); UCometChatSubsystem* Chat = GetGameInstance()->GetSubsystem(); // Message events Chat->OnTextMessageReceived.AddDynamic(this, &AMyActor::HandleTextMessage); Chat->OnTypingStarted.AddDynamic(this, &AMyActor::HandleTypingStarted); // User events Chat->OnUserOnline.AddDynamic(this, &AMyActor::HandleUserOnline); // Group events Chat->OnGroupMemberJoined.AddDynamic(this, &AMyActor::HandleMemberJoined); // Connection events Chat->OnConnected.AddDynamic(this, &AMyActor::HandleConnected); Chat->OnDisconnected.AddDynamic(this, &AMyActor::HandleDisconnected); } ``` *** ## MessageListener Events These fire when messages, typing indicators, receipts, or reactions arrive. | Delegate | Payload | Fires When | | ------------------------------ | ------------------------------ | ------------------------------------------------ | | `OnTextMessageReceived` | `FCometChatMessage` | A text message arrives | | `OnMediaMessageReceived` | `FCometChatMessage` | A media (image/video/audio/file) message arrives | | `OnCustomMessageReceived` | `FCometChatMessage` | A custom message arrives | | `OnInteractiveMessageReceived` | `FCometChatMessage` | An interactive message arrives | | `OnInteractionGoalCompleted` | `FCometChatInteractionReceipt` | An interaction goal is completed | | `OnTypingStarted` | `FCometChatTypingIndicator` | A user starts typing | | `OnTypingEnded` | `FCometChatTypingIndicator` | A user stops typing | | `OnMessagesDelivered` | `FCometChatMessageReceipt` | Messages delivered to recipient | | `OnMessagesRead` | `FCometChatMessageReceipt` | Messages read by recipient | | `OnMessagesDeliveredToAll` | `FCometChatMessageReceipt` | Messages delivered to all group members | | `OnMessagesReadByAll` | `FCometChatMessageReceipt` | Messages read by all group members | | `OnMessageEdited` | `FCometChatMessage` | A message is edited | | `OnMessageDeleted` | `FCometChatMessage` | A message is deleted | | `OnTransientMessageReceived` | `FCometChatTransientMessage` | A transient (ephemeral) message arrives | | `OnMessageReactionAdded` | `FCometChatReactionEvent` | A reaction is added to a message | | `OnMessageReactionRemoved` | `FCometChatReactionEvent` | A reaction is removed from a message | | `OnMessageModerated` | `FCometChatMessage` | A message moderation status changes | | `OnAIAssistantMessageReceived` | `FCometChatMessage` | An AI assistant message arrives | | `OnAIToolResultReceived` | `FCometChatMessage` | An AI tool result arrives | | `OnAIToolArgumentsReceived` | `FCometChatMessage` | AI tool arguments arrive | Bind to **On Text Message Received**. The custom event receives an `FCometChatMessage`. Use `ReceiverType` to check if it's a `user` (1:1) or `group` message. ```cpp theme={null} void AMyActor::HandleTextMessage(const FCometChatMessage& Message) { if (Message.ReceiverType == TEXT("group")) { UE_LOG(LogTemp, Log, TEXT("[Group %s] %s: %s"), *Message.ReceiverUid, *Message.SenderName, *Message.Text); } else { UE_LOG(LogTemp, Log, TEXT("[DM] %s: %s"), *Message.SenderName, *Message.Text); } } ``` *** ## UserListener Events These fire when a user's online status changes. | Delegate | Payload | Fires When | | --------------- | ---------------- | ------------------- | | `OnUserOnline` | `FCometChatUser` | A user comes online | | `OnUserOffline` | `FCometChatUser` | A user goes offline | Bind to **On User Online** / **On User Offline**. The custom event receives an `FCometChatUser` with the user's full profile. ```cpp theme={null} void AMyActor::HandleUserOnline(const FCometChatUser& User) { UE_LOG(LogTemp, Log, TEXT("%s is now online"), *User.Name); } void AMyActor::HandleUserOffline(const FCometChatUser& User) { UE_LOG(LogTemp, Log, TEXT("%s went offline"), *User.Name); } ``` *** ## GroupListener Events These fire when group membership changes occur. | Delegate | Payload | Fires When | | --------------------------- | ------------------------------------------------------------------------- | ---------------------------------------- | | `OnGroupMemberJoined` | `FCometChatAction`, `FCometChatUser`, `FCometChatGroup` | A user joins a group | | `OnGroupMemberLeft` | `FCometChatAction`, `FCometChatUser`, `FCometChatGroup` | A user leaves a group | | `OnGroupMemberKicked` | `FCometChatAction`, `FCometChatUser`, `FCometChatUser`, `FCometChatGroup` | A member is kicked (includes who kicked) | | `OnGroupMemberBanned` | `FCometChatAction`, `FCometChatUser`, `FCometChatUser`, `FCometChatGroup` | A member is banned (includes who banned) | | `OnGroupMemberUnbanned` | `FCometChatAction`, `FCometChatUser`, `FCometChatUser`, `FCometChatGroup` | A member is unbanned | | `OnGroupMemberScopeChanged` | `FCometChatScopeChangeEvent` | A member's role/scope changes | | `OnMemberAddedToGroup` | `FCometChatAction`, `FCometChatUser`, `FCometChatUser`, `FCometChatGroup` | A member is added by another user | Bind to **On Group Member Joined**. The custom event receives the action, the user who joined, and the group. ```cpp theme={null} void AMyActor::HandleMemberJoined(const FCometChatAction& Action, const FCometChatUser& JoinedUser, const FCometChatGroup& Group) { UE_LOG(LogTemp, Log, TEXT("%s joined group %s"), *JoinedUser.Name, *Group.Name); } ``` *** ## ConnectionListener Events These fire when the WebSocket connection state changes. | Delegate | Payload | Fires When | | -------------------- | ----------------- | -------------------------------- | | `OnConnected` | — | WebSocket connection established | | `OnConnecting` | — | SDK is attempting to connect | | `OnDisconnected` | — | WebSocket connection lost | | `OnFeatureThrottled` | — | A feature is being rate-limited | | `OnConnectionError` | `FCometChatError` | A connection error occurred | Bind to **On Connected**, **On Disconnected**, etc. These are parameterless events (except `OnConnectionError` which provides an `FCometChatError`). ```cpp theme={null} void AMyActor::HandleConnected() { UE_LOG(LogTemp, Log, TEXT("Connected to CometChat")); } void AMyActor::HandleDisconnected() { UE_LOG(LogTemp, Warning, TEXT("Disconnected from CometChat")); } void AMyActor::HandleConnectionError(const FCometChatError& Error) { UE_LOG(LogTemp, Error, TEXT("Connection error: %s — %s"), *Error.Code, *Error.Message); } ``` *** ## LoginListener Events These fire on login/logout lifecycle events. | Delegate | Payload | Fires When | | ----------------- | ----------------- | --------------- | | `OnLoginSuccess` | `FCometChatUser` | Login succeeds | | `OnLoginFailure` | `FCometChatError` | Login fails | | `OnLogoutSuccess` | — | Logout succeeds | | `OnLogoutFailure` | `FCometChatError` | Logout fails | Bind to **On Login Success** to receive the logged-in `FCometChatUser` after authentication completes. ```cpp theme={null} void AMyActor::HandleLoginSuccess(const FCometChatUser& User) { UE_LOG(LogTemp, Log, TEXT("Logged in as %s (%s)"), *User.Name, *User.Uid); } void AMyActor::HandleLoginFailure(const FCometChatError& Error) { UE_LOG(LogTemp, Error, TEXT("Login failed: %s"), *Error.Message); } ``` *** ## AIAssistantListener Events These fire when AI assistant interactions occur. | Delegate | Payload | Fires When | | -------------------- | ---------------------------- | ---------------------------- | | `OnAIAssistantEvent` | `FCometChatAIAssistantEvent` | An AI assistant event occurs | Bind to **On AI Assistant Event**. The custom event receives an `FCometChatAIAssistantEvent` with event type, data, conversation ID, and sender UID. ```cpp theme={null} void AMyActor::HandleAIAssistantEvent(const FCometChatAIAssistantEvent& Event) { UE_LOG(LogTemp, Log, TEXT("AI event [%s] in conversation %s: %s"), *Event.EventType, *Event.ConversationId, *Event.Data); } ``` *** ## Error Handling — FCometChatError Many delegates and failure callbacks provide an `FCometChatError` struct with details about what went wrong. Always handle errors gracefully in your game. ### FCometChatError | Property | Type | Description | | --------- | --------- | ------------------------------------------------------------------------ | | `Code` | `FString` | Machine-readable error code (e.g., `"ERR_AUTH_FAILED"`, `"ERR_NETWORK"`) | | `Message` | `FString` | Human-readable error description | | `Details` | `FString` | Additional context (may be empty) | ### Handling Errors All async nodes have an **On Failure** pin. Wire it to a custom event that receives an `FString` error message. Connection and login listener events provide the full `FCometChatError` struct. ```cpp theme={null} // Async node failure handler (simple string) void AMyActor::HandleError(const FString& Error) { UE_LOG(LogTemp, Error, TEXT("Operation failed: %s"), *Error); // Show error in UI, retry, or fallback } // Connection/Login listener error handler (full struct) void AMyActor::HandleConnectionError(const FCometChatError& Error) { UE_LOG(LogTemp, Error, TEXT("Error [%s]: %s — %s"), *Error.Code, *Error.Message, *Error.Details); // Common patterns: // - "ERR_NETWORK": Show "No internet" banner, retry with backoff // - "ERR_AUTH_FAILED": Redirect to login screen // - "ERR_RATE_LIMIT": Wait and retry after delay } ``` **Best practice**: Always bind `OnConnectionError` and `OnLoginFailure` delegates early. Network issues are common in games — show a reconnection banner rather than silently failing. *** ## Manual Connection By default, the SDK auto-connects the WebSocket after login. For games with loading screens or lobbies where real-time events aren't needed immediately, you can manage the connection manually. ### Setup Manual Mode Set `bAutoEstablishSocketConnection = false` in `FCometChatAppSettings` when configuring: ```cpp theme={null} FCometChatAppSettings Settings; Settings.Region = TEXT("us"); Settings.bAutoEstablishSocketConnection = false; Chat->ConfigureWithSettings(TEXT("YOUR_APP_ID"), Settings); ``` ### Connect / Disconnect / Ping * **Connect Async** — Establish the WebSocket after login * **Disconnect Async** — Close the WebSocket (user stays authenticated) * **Ping Async** — Verify the connection is alive ```cpp theme={null} // Connect when entering chat area auto* Connect = UCometChatConnectAction::Connect(this); Connect->OnSuccess.AddDynamic(this, &AMyActor::OnConnected); Connect->OnFailure.AddDynamic(this, &AMyActor::HandleError); Connect->Activate(); // Disconnect when leaving chat area auto* Disconnect = UCometChatDisconnectAction::Disconnect(this); Disconnect->OnSuccess.AddDynamic(this, &AMyActor::OnDisconnected); Disconnect->Activate(); // Health check auto* Ping = UCometChatPingAction::Ping(this); Ping->OnSuccess.AddDynamic(this, &AMyActor::OnPingOk); Ping->OnFailure.AddDynamic(this, &AMyActor::OnPingFailed); Ping->Activate(); ``` ### Query Connection State ```cpp theme={null} ECometChatConnectionState State = Chat->GetConnectionStatus(); // Connected, Connecting, Disconnected, or FeatureThrottled ``` For full details on manual connection management, see [Advanced Configuration](/sdk/unreal/advanced-configuration). *** ## Next Steps Send and receive typing state. Drop-in chat panel and button widgets.