Mark messages as read

To keep the most up-to-date and accurate read status of messages for all group channel members, the markAsRead() method should be called every time one of the members reads messages by entering the channel from a channel list or bringing the chat view to the foreground.

For the member who sent the message to the channel, the Sendbird server updates the member's read receipt to the time when the message was sent. The read receipts of other channel members are updated when the markAsRead() method is called.

If a member opens a channel and markAsReadAll() is called, the Sendbird server updates both the unread message count of the individual channel and the total unread message count of all the group channels joined by the member. The server then triggers the onUnreadMemberStatusUpdated() method in the channel event handler to notify the change of read status to all other members' devices.

If a new member joins the channel, the method works differently based on the value of the display_past_message property of your Sendbird application. If the property is set to true, the new member’s read receipt is updated to the sent time of the last message in the channel. If set to false, the property's value is 0.

await groupChannel.markAsRead();
// ...

const channelHandler = new GroupChannelHandler({
    onUnreadMemberCountUpdated: (channel: GroupChannel) => {
        // ...
    },
});
sb.groupChannel.addGroupChannelHandler(UNIQUE_HANDLER_ID, channelHandler);

Note: The display_past_message property determines whether to display past messages to newly joined members when they enter the channel. This property is also linked to the Chat history option, which can be managed on Sendbird Dashboard under Settings > Chat > Channels > Group channels.