> ## Documentation Index
> Fetch the complete documentation index at: https://cometchat-013b37f0.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Delivery & Read Receipts

## Mark Messages as Delivered

*In other words, as a recipient, how do I inform the sender that I've received a message?*

You can mark the messages for a particular conversation as read using the `markAsDelivered()` method. This method takes the below parameters as input:

| Parameter    | Information                                                                                                |
| ------------ | ---------------------------------------------------------------------------------------------------------- |
| id           | The ID of the message above which all the messages for a particular conversation are to be marked as read. |
| receiverUid  | In case of one to one conversation message's sender UID will be the receipt's receiver Id.                 |
| receiverType | Type of the receiver. Could be either of the two values( user or group).                                   |

Messages for both User conversation and Groups can be marked as read using this method.

Ideally, you would like to mark all the messages as delivered for any conversation when the user opens the chat window for that conversation. This includes two scenarios:

1. **When the list of messages for the conversation is fetched**: In this case you need to obtain the last message in the list of messages and pass the message to the markAsDelivered() method.
2. **When the user is on the chat window and a real-time message is received:** In this case you need to obtain the message and pass it to the markAsDelivered() method.

This method will mark all the messages before the messageId specified, for the conversation with receiverId and receiverType(user/group) as read.

In case you would like to be notified of an error if the receipts fail to go through you can use `markAsDelivered()` method with the callbacks as shown below:

<Tabs>
  <Tab title="Dart">
    ```dart theme={null}
    CometChat.markAsDelivered(message, onSuccess: (String unused) {
      debugPrint("markAsDelivered : $unused ");
    }, onError: (CometChatException e) {
      debugPrint("markAsDelivered unsuccessful : ${e.message} ");
    });
    ```
  </Tab>
</Tabs>

## Mark Messages as Read

*In other words, as a recipient, how do I inform the sender I've read a message?*

You can mark the messages for a particular conversation as read using the `markAsRead()` method. This method takes the below parameters as input:

Messages for both user and group conversations can be marked as read using this method.

Ideally, you should mark all the messages as read for any conversation when the user opens the chat window for that conversation. This includes two scenarios:

1. **When the list of messages for the conversation is fetched**: In this case you need to obtain the last message in the list of messages and pass the message to the `markAsRead()` method.
2. **When the user is on the chat window and a real-time message is received:** In this case you need to obtain the message and pass it to the `markAsRead()` method

This method will mark all the messages before the message specified, for the conversation with `receiverId` and `receiverType` (user/group) as read.

<Tabs>
  <Tab title="Dart">
    ```dart theme={null}
    CometChat.markAsRead(message)
    ```
  </Tab>
</Tabs>

In case you would like to be notified of an error if the receipts fail to go through you can use the `markAsRead()` method with the callbacks as shown below:

<Tabs>
  <Tab title="Dart">
    ```dart theme={null}
    CometChat.markAsRead(message, onSuccess: (String unused) {
          debugPrint("markAsRead : $unused ");
          reinitiateList();
        }, onError: (CometChatException e) {
          debugPrint("markAsRead unsuccessfull : ${e.message} ");
        });
    ```
  </Tab>
</Tabs>

## Receive Delivery & Read Receipts

*In other words, as a recipient, how do I know when a message I sent has been delivered or read by someone?*

### Real-time Receipts

Real-time events for messages of a conversation being read or delivered can be obtained in the `onMessagesRead()` and the `onMessagesDelivered()` methods of the `MessageListener` class.

<Tabs>
  <Tab title="Dart">
    ```dart theme={null}
    class Class_Name  with MessageListener {

      //CometChat.addMessageListener("listenerId", this);
    @override
      void onMessagesDelivered(MessageReceipt messageReceipt) {
        // TODO: implement onMessagesDelivered
        
      }
      
      @override
      void onMessagesRead(MessageReceipt messageReceipt) {
       // TODO: implement onMessagesRead
      }


    }
    ```
  </Tab>
</Tabs>

You will receive events in the form of `MessageReceipt` objects. The message receipt contains the following parameters:

| Parameter      | Information                                                                                                          |
| -------------- | -------------------------------------------------------------------------------------------------------------------- |
| `messageId`    | The ID of the message prior to which all the messages for that particular conversation have been marked as read.     |
| `sender`       | User object containing the details of the user who has marked the message as read.                                   |
| `receiverId`   | Id of the receiver whose conversation has been marked as read.                                                       |
| `receiverType` | Type of the receiver (user/group)                                                                                    |
| `receiptType`  | Type of the receipt (read/delivered)                                                                                 |
| `deliveredAt`  | The timestamp of the time when the message was delivered. This will only be present if the receiptType is delivered. |
| `readAt`       | The timestamp of the time when the message was read. This will only be present when the receiptType is read.         |

### Missed Receipts

You will receive message receipts when you load offline messages. For groups, we do not include the list the users that have received it. You need to call the `getMessageReceipts()` method for it.

While fetching messages in bulk, if the message is a part of a one-on-one conversation, the message object will have two fields viz. `deliveredAt` and `readAt` which hold the timestamp for the time the message was delivered and read respectively. Using these two variables, the delivery and read status for a one-on-one conversation message can be obtained.

However, for a group conversation message, the `deliveredAt` and `readAt` fields are set once a message is delivered to or read by all members of the group.

### Receipt History for a Single Message

In order to fetch the message receipts, you can use the `getMessageReceipts()` method.

<Tabs>
  <Tab title="Dart">
    ```dart theme={null}
    private int messageId = 10101;

    CometChat.getMessageReceipts(messageId, new CometChat.CallbackListener<List<MessageReceipt>>() {
      @Override
        public void onSuccess(List<MessageReceipt> messageReceipts) {
        	// Handle message receipts
      }

      @Override
        public void onError(CometChatException e) {
        // Handle error
      }
    });
    ```
  </Tab>
</Tabs>

You will receive a list of `MessageReceipt` objects in the `onSuccess()` method.