Documentation Index
Fetch the complete documentation index at: https://www.cometchat.com/docs/llms.txt
Use this file to discover all available pages before exploring further.
Before diving into individual features, it helps to understand the three building blocks of the plugin: the Subsystem, Latent Async Nodes, and Real-Time Delegates.
The Subsystem
UCometChatSubsystem is a UGameInstanceSubsystem — Unreal creates one instance automatically when your game starts, and it lives for the entire session. You never need to spawn or manage it yourself.
Get a reference from any Blueprint:Get Game Instance → Get Subsystem → select CometChatSubsystem
UCometChatSubsystem* Chat = GetGameInstance()->GetSubsystem<UCometChatSubsystem>();
- Configuration — storing your App ID and Region
- SDK lifecycle — creating and shutting down the underlying C++ SDK
- Auth state — tracking whether a user is logged in
- Real-time events — exposing multicast delegates for push notifications
Latent Async Nodes
Every SDK operation that talks to the network (Login, Send Message, Get Messages, etc.) is exposed as a latent async action — a Blueprint node with two output execution pins:
| Pin | When it fires |
|---|
| On Success | The operation completed successfully. Output data is available on the success pin. |
| On Failure | Something went wrong. An FString error message describes what happened. |
How an Async Node Executes
In C++, these are UCometChatAsyncAction subclasses. You create them with a static factory method, bind delegates, and call Activate():
auto* Action = UCometChatLoginAction::LoginAsync(this, TEXT("user-123"), TEXT("auth-key"));
Action->OnSuccess.AddDynamic(this, &AMyActor::HandleLoginSuccess);
Action->OnFailure.AddDynamic(this, &AMyActor::HandleLoginFailure);
Action->Activate();
All async callbacks fire on the Game Thread, so it’s safe to update UI, spawn actors, or call other engine APIs directly from the callback.
Available Async Nodes
| Category | Node | Success Output |
|---|
| Auth | Login Async | — |
| Auth | Logout Async | — |
| Messaging | Send Message Async | FCometChatMessage |
| Messaging | Send Group Message Async | FCometChatMessage |
| Messaging | Get Messages Async | TArray<FCometChatMessage> |
| Messaging | Get Group Messages Async | TArray<FCometChatMessage> + FCometChatPagination |
| Users | Get User Async | FCometChatUser |
| Groups | Create Group Async | FCometChatGroup |
| Groups | Join Group Async | — |
| Groups | Leave Group Async | — |
Real-Time Delegates
The Subsystem exposes five multicast delegates for real-time push events. Bind to them once after calling Configure, and they’ll fire whenever the server pushes an update.
| Delegate | Payload Type | Fires When |
|---|
OnMessageReceived | FCometChatMessage | A new message arrives in any conversation |
OnPresenceChanged | FCometChatPresence | A user goes online, offline, or away |
OnTypingChanged | FCometChatTypingEvent | A user starts or stops typing |
OnReceiptReceived | FCometChatReceiptEvent | A message is delivered or read |
OnConnectionStateChanged | ECometChatConnectionState | WebSocket connects, disconnects, or reconnects |
Drag off the Subsystem reference and search for the delegate name (e.g., On Message Received). Use Bind Event to wire it to a custom event.
UCometChatSubsystem* Chat = GetGameInstance()->GetSubsystem<UCometChatSubsystem>();
Chat->OnMessageReceived.AddDynamic(this, &AMyActor::HandleNewMessage);
Chat->OnPresenceChanged.AddDynamic(this, &AMyActor::HandlePresence);
Chat->OnTypingChanged.AddDynamic(this, &AMyActor::HandleTyping);
Chat->OnReceiptReceived.AddDynamic(this, &AMyActor::HandleReceipt);
Chat->OnConnectionStateChanged.AddDynamic(this, &AMyActor::HandleConnection);
Bind your delegates before calling Login. Events that arrive between Login and binding will be missed.
Data Types
The plugin uses Unreal-native USTRUCT types — no std::string or STL containers leak into your game code.
FCometChatUser
| Property | Type | Description |
|---|
Uid | FString | Unique user identifier |
Name | FString | Display name |
AvatarUrl | FString | URL to the user’s avatar image |
Status | FString | Current status text |
FCometChatMessage
| Property | Type | Description |
|---|
Id | FString | Unique message identifier |
SenderUid | FString | UID of the sender |
ReceiverUid | FString | UID of the receiver (user or group) |
Text | FString | Message body |
SentAt | int64 | Unix timestamp (seconds) when sent |
Type | FString | Message type: text, image, file, custom |
Category | FString | Category: message, action, call, custom |
ReceiverType | FString | user or group |
ConversationId | FString | Conversation identifier |
SenderName | FString | Sender’s display name |
SenderAvatar | FString | Sender’s avatar URL |
UpdatedAt | int64 | Unix timestamp of last update |
FCometChatGroup
| Property | Type | Description |
|---|
Guid | FString | Unique group identifier |
Name | FString | Group display name |
Description | FString | Group description |
MemberIds | TArray<FString> | UIDs of group members |
| Property | Type | Description |
|---|
Total | int32 | Total messages available |
Count | int32 | Messages returned in this page |
PerPage | int32 | Page size requested |
CurrentPage | int32 | Current page number |
TotalPages | int32 | Total pages available |
HasMore | bool | Whether more pages exist |
NextCursor | int32 | Message ID to pass as BeforeMessageId for the next page |
FCometChatPresence
| Property | Type | Description |
|---|
Uid | FString | User identifier |
Status | ECometChatPresenceStatus | Online, Offline, or Away |
LastActiveAt | int64 | Unix timestamp of last activity |
FCometChatTypingEvent
| Property | Type | Description |
|---|
Uid | FString | User who is typing |
ConversationId | FString | Conversation where typing is happening |
bIsTyping | bool | true if started typing, false if stopped |
FCometChatReceiptEvent
| Property | Type | Description |
|---|
MessageId | FString | The message this receipt is for |
Uid | FString | User who triggered the receipt |
Status | FString | delivered or read |
Timestamp | int64 | Unix timestamp of the receipt |
Enums
ECometChatConnectionState
| Value | Description |
|---|
Connected | WebSocket is connected and active |
Disconnected | WebSocket is disconnected |
Reconnecting | SDK is attempting to reconnect |
| Value | Description |
|---|
Online | User is currently online |
Offline | User is offline |
Away | User is away |
