Messaging

Overview of CometChat iOS SDK messaging including sending text, media, and custom messages with real-time delivery, read receipts, and threading.

Quick Reference for AI Agents & Developers

• Send text: CometChat.sendTextMessage(message:onSuccess:onError:)
• Send media: CometChat.sendMediaMessage(message:onSuccess:onError:)
• Receive messages: CometChat.addMessageListener("UNIQUE_ID", self)
• Fetch history: MessagesRequest.MessageRequestBuilder().build() → messagesRequest.fetchPrevious(onSuccess:onError:)
• Message types: TextMessage, MediaMessage, CustomMessage, InteractiveMessage (all extend BaseMessage)
• Related: Send Message · Receive Message · Typing Indicators

Messaging is one of the core features of CometChat. We’ve thoughtfully created methods to help you send, receive and fetch message history.

At the minimum, you must add code for sending messages and receiving messages.

Once you’ve implemented that, you can proceed to more advanced features like typing indicators and delivery & read receipts.

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Message Data Models

All message types in CometChat inherit from the BaseMessage class. Understanding these data models is essential for working with messages.

BaseMessage Properties

The BaseMessage class contains properties common to all message types:

Property	Type	Description
id	Int	Server-assigned unique message identifier
muid	String	Client-generated unique identifier
senderUid	String	UID of the message sender
receiverUid	String	UID of the receiver (user or group)
messageType	MessageType	Type: .text, .image, .video, .audio, .file, .custom
receiverType	ReceiverType	.user or .group
sentAt	Int	Unix timestamp (seconds) when sent
deliveredAt	Double	Unix timestamp when delivered
readAt	Double	Unix timestamp when read
deliveredToMeAt	Double	When delivered to current user
readByMeAt	Double	When read by current user
sender	User?	User object of the sender
receiver	AppEntity?	User or Group object
metaData	[String: Any]?	Custom metadata dictionary
conversationId	String	Unique conversation identifier
parentMessageId	Int	Parent message ID (for threads)
replyCount	Int	Number of replies
mentionedUsers	[User]	Array of mentioned users
mentionedMe	Bool	Whether current user is mentioned
reactions	[ReactionCount]	Reaction counts
editedAt	Double	When edited
deletedAt	Double	When deleted

TextMessage

Extends BaseMessage with:

Property	Type	Description
text	String	The text content
tags	[String]?	Message tags

MediaMessage

Extends BaseMessage with:

Property	Type	Description
attachment	Attachment?	Single attachment
attachments	[Attachment]?	Multiple attachments
caption	String?	Caption text
tags	[String]?	Message tags

CustomMessage

Extends BaseMessage with:

Property	Type	Description
customData	[String: Any]?	Custom JSON data
type	String?	Custom type identifier
subType	String?	Custom subtype

Attachment

Property	Type	Description
fileName	String	File name
fileExtension	String	File extension
fileSize	Double	Size in bytes
fileMimeType	String	MIME type
fileUrl	String	URL of the file

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Success & Failure Responses

Send Message Success

When a message is sent successfully, you receive the complete message object with server-assigned properties:

Swift

CometChat.sendTextMessage(message: textMessage, onSuccess: { (sentMessage) in
    // sentMessage.id - Server-assigned message ID
    // sentMessage.sentAt - Server timestamp
    // sentMessage.sender - Populated User object
    // sentMessage.conversationId - Conversation identifier
    print("Message ID: \(sentMessage.id)")
    print("Sent at: \(sentMessage.sentAt)")
}, onError: { (error) in
    print("Error: \(error?.errorDescription ?? "")")
})

Common Error Codes

Error Code	Description
ERR_NOT_LOGGED_IN	User is not logged in
ERR_UID_NOT_FOUND	Receiver UID not found
ERR_GUID_NOT_FOUND	Group GUID not found
ERR_BLOCKED_BY_RECEIVER	Blocked by receiver
ERR_NOT_A_MEMBER	Not a member of the group