Overview - CometChat Docs

A Conversation represents an ongoing message exchange between a user and another user (1-on-1) or a group. Each conversation tracks the last message, unread count, and metadata — making it easy to build a “Recent Chats” list.

Key behaviors

Conversations are automatically created when the first message is exchanged.
For groups with more than 300 members, conversations and unread message counts are not updated.
Conversations can have up to 25 tags, each up to 100 characters (UTF8mb4).
The lastMessage property is not visible if the message has been deleted or if a new group has no messages yet.

How conversations connect to other resources

Users — A 1-on-1 conversation is between two Users. The conversationWith field contains the other user’s details.
Groups — A group conversation is tied to a Group. The conversationWith field contains the group’s details.
Messages — The lastMessage field reflects the most recent Message in the conversation.

Available operations

Operation	Method	Endpoint	Description
List Conversations	`GET`	`/conversations`	Retrieve all conversations for a user
Get Conversation	`GET`	`/conversations/{conversationId}`	Retrieve a specific conversation (deprecated)
Delete Conversation	`DELETE`	`/conversations/{conversationId}`	Delete a conversation for a user (deprecated)
Get User Conversation	`GET`	`/users/{uid}/conversation`	Retrieve a 1-on-1 conversation with a specific user
Get Group Conversation	`GET`	`/groups/{guid}/conversation`	Retrieve a group conversation
Update User Conversation	`PUT`	`/users/{uid}/conversation`	Update tags on a 1-on-1 conversation
Update Group Conversation	`PUT`	`/groups/{guid}/conversation`	Update tags on a group conversation
Reset User Conversation	`DELETE`	`/users/{uid}/conversation`	Reset unread count for a 1-on-1 conversation
Reset Group Conversation	`DELETE`	`/groups/{guid}/conversation`	Reset unread count for a group conversation
Mark User Conversation as Read	`POST`	`/users/{uid}/conversation/read`	Mark all messages as read in a 1-on-1 conversation
Mark Group Conversation as Read	`POST`	`/groups/{guid}/conversation/read`	Mark all messages as read in a group conversation
Mark User Conversation as Delivered	`POST`	`/users/{uid}/conversation/delivered`	Mark all messages as delivered in a 1-on-1 conversation
Mark Group Conversation as Delivered	`POST`	`/groups/{guid}/conversation/delivered`	Mark all messages as delivered in a group conversation
Mark Conversation as Unread	`DELETE`	`/users/{uid}/conversation/read`	Mark a user conversation as unread
Mark Group Conversation as Unread	`DELETE`	`/groups/{guid}/conversation/read`	Mark a group conversation as unread

Conversation properties

Property	Type	Description
conversationId	string	Unique conversation identifier. Format: `user_{uid}` for 1-on-1 or `group_{guid}` for group conversations.
conversationType	string	Type of conversation: `user` or `group`.
unreadMessageCount	integer	Number of unread messages in this conversation.
lastMessage	object	Details of the most recent message in the conversation. Not present if the message was deleted or if a new group has no messages.
conversationWith	object	Details of the other user (for 1-on-1) or the group (for group conversations).
createdAt	integer	UNIX timestamp of when the conversation was created.
updatedAt	integer	UNIX timestamp of when the conversation was last updated.

Error handling

Error Code	Description
`ERR_UID_NOT_FOUND`	The specified user does not exist
`ERR_CONVERSATION_NOT_FOUND`	The specified conversation does not exist. This error code applies only to the deprecated Get Conversation and Delete Conversation APIs.
`ERR_CONVERSATION_NOT_ACCESSIBLE`	The conversation is not accessible to the user. A user can access their own one-to-one conversations, and group conversations they are a member of. This error is also thrown when the conversation has no messages yet, as the conversation has not been created on CometChat.

For the complete list of error codes, see Error Guide. For all system limits (unread counts, tag counts, group thresholds, etc.), see Properties and Constraints.

​Key behaviors

​How conversations connect to other resources

​Available operations

​Conversation properties

​Error handling

Key behaviors

How conversations connect to other resources

Available operations

Conversation properties

Error handling