> ## 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.

# Overview

> Retrieve and manage conversations that track the latest messages and unread counts for each user.

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](/rest-api/users). The `conversationWith` field contains the other user's details.
* **Groups** — A group conversation is tied to a [Group](/rest-api/groups). The `conversationWith` field contains the group's details.
* **Messages** — The `lastMessage` field reflects the most recent [Message](/rest-api/messages) in the conversation.

### Available operations

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

For the complete list of error codes, see [Error Guide](/articles/error-guide).

For all system limits (unread counts, tag counts, group thresholds, etc.), see [Properties and Constraints](/articles/properties-and-constraints).