Manage server-side messages

Updated

Introduces how to use the Agora Chat SDK to retrieve messages from the server.

The Chat SDK stores historical messages on the chat server. When a chat user logs in from a different device, you can retrieve the historical messages from the server, so that the user can also browse these messages on the new device. Additionally, the Chat SDK supports adding tags to conversation, with a maximum of 20 tags allowed per conversation.

This page introduces how to use the Chat SDK to retrieve, delete, and tag messages and conversations.

Understand the tech

The Chat SDK uses ChatManager to retrieve historical messages from the server. The following are the core methods:

  • asyncFetchConversationsFromServer: Retrieves a list of conversations stored on the server.
  • asyncFetchHistoryMessages: Retrieves historical messages of a conversation from the server according to FetchMessageOption, the parameter configuration class for retrieving historical messages.
  • asyncPinConversation: Pins conversations.
  • asyncFetchPinnedConversationsFromServer: Retrieves pinned conversations.
  • asyncPinMessage: Pins a message in a conversation.
  • asyncUnPinMessage: Unpin a message in a conversation.
  • asyncGetPinnedMessagesFromServer: Get a list of pinned messages in a conversation.
  • removeMessagesFromServer: One-way deletion of historical messages on the server based on message time or message ID.
  • deleteConversationFromServer: Deletes conversations and their historical messages from the server.
  • asyncAddConversationMark: Tags a conversation.
  • asyncRemoveConversationMark: Removes a conversation tag.
  • asyncGetConversationsFromServerWithCursor: Queries conversations from the server by a conversation tag.

The Chat SDK uses IChatManager to retrieve historical messages from the server. The following are the core methods:

  • GetConversationsFromServerWithPage: Retrieve conversations stored on the server with pagination.
  • FetchHistoryMessagesFromServerBy: Retrieves historical messages of a conversation from the server according to FetchServerMessagesOption, the parameter configuration class for retrieving historical messages.
  • PinConversation: Pins a conversation.
  • GetConversationsFromServerWithCursor: Retrieves a list of pinned conversations.
  • RemoveMessagesFromServer: Deletes historical messages from the server unidirectionally.
  • DeleteConversationFromServer: Deletes conversations and their historical messages from the server.

Prerequisites

Before proceeding, ensure that you meet the following requirements:

  • You have integrated the Chat SDK, initialized the SDK and implemented the functionality of registering accounts and login. For details, see Chat SDK quickstart.
  • You understand the API call frequency limits as described in Limitations.

Implementation

This section shows how to implement retrieving conversations and messages.

Retrieve a list of conversations from the server

Call GetConversationsFromServerWithCursor to retrieve conversations from the server with pagination. You can set the pinOnly parameter in this method to determine whether to retrieve the list of pinned conversations:

  • If pinOnly is set to false, you can retrieve the list of pinned and unpinned conversations. The SDK returns the conversation list in the reverse chronological order of when conversations are active (the timestamp of the last message in the conversation).
  • If pinOnly is set to true, you can only retrieve the list of pinned conversations. The SDK returns the pinned conversations in the reverse chronological order of when they were pinned. Up to 50 pinned conversations can be retrieved.

In the conversation list, each conversation object contains the conversation ID, conversation type, whether the conversation is pinned, the pinned time (the value is 0 for an unpinned conversation), and the last message in the conversation. After the conversation list is retrieved from the server, the local conversation list will be updated accordingly. We recommend calling this method when the app is first installed, or when there is no conversation on the local device. Otherwise, you can call LoadAllConversations to retrieve conversations on the local device.

For each end user, the server stores 100 conversations by default. When this limit is exceeded, new conversations will start overwriting the old ones. If the entire message history in a conversation expires, the conversation becomes empty. When pulling the conversation list from the server, these empty conversations are not included by default. To include them, set Options#EnableEmptyConversation to true when initializing the SDK. In this case, empty conversations will occupy the conversations pull quota, regardless of whether they are needed when pulling. To change this, contact support@agora.io.

// limit: The number of conversations that you expect to get on each page. The value range is [1,50].
int limit = 10;
string cursor = "";
bool pinOnly = false; // `false`:Get all conversations; `true`: Get the list of pinned conversations.
SDKClient.Instance.ChatManager.GetConversationsFromServerWithCursor(pinOnly, cursor, limit, new ValueCallBack>(
   onSuccess: (result) =>
   {
       // Traverse the obtained conversation list
       foreach (var conv in result.Data)
       {

       }
       // The cursor for the next request
       string nextCursor = result.Cursor;
   },
   onError: (code, desc) =>
   {

   }
));

Retrieve historical messages of the specified conversation

After retrieving conversations, you can retrieve historical messages from the server.

You can set the search direction to retrieve messages in the chronological or reverse chronological order of when the server receives them, the message type, the time period, the message sender, as well as whether to save the retrieved message to the local database.

If you have integrated Chat SDK after June 8, 2023, you can retrieve historical messages even before joining the Chat Group. For earlier implementations, contact support@agora.io to enable this.

The Agora Chat server stores the full message history for a certain period of time depending on your subscribed Chat plan. After an end user logs back into Agora Chat, the servers automatically send offline messages to them, that is, messages transmitted when that end user was offline. Offline messages are a subset of the full message history stored on Agora Chat server. Sending only a subset of messages prevents distributing too many messages to a single device, which can overwhelm it and slow down the end user login. Agora Chat server stores and manages these offline messages for every end user in the following way:

  • 1
    private chat: Store 500 offline messages by default;
  • Chat Group: Store 200 offline messages by default;
  • Chatroom: Doesn't store offline messages. However, whenever an end user joins a chatroom, Agora Chat servers push the 10 latest messages/chatroom to them, by default. This number can be adjusted to 200 messages/chatroom without additional charges.

For users to receive more offline messages, use the client API or a webhook to sync with Agora Chat's server. End users can also store additional messages on their local database.

To ensure data reliability, we recommend retrieving less than 50 historical messages for each method call. To retrieve more than 50 historical messages, call this method multiple times. Once the messages are retrieved, the SDK automatically updates these messages in the local database.

We recommend that you retrieve 20 messages each time, with a maximum of 50. During paginated query, if the total number of messages that meet the query conditions is greater than the number of pageSize, the number of messages of pageSize will be returned. If it is less than the number of pageSize, the actual number will be returned. When the message query is completed, the number of returned messages is less than the number of pageSize.

Since SDK v1.4.0, for a single group conversation you can retrieve messages sent by specific members (rather than all members) by setting the FromIds list in FetchServerMessagesOption. FromIds replaces the deprecated From attribute.

Refer to the following code sample:

FetchServerMessagesOption option = new FetchServerMessagesOption();
option.IsSave = false;
option.Direction = MessageSearchDirection.UP;
// Since SDK v1.4.0, for a group conversation, set FromIds to retrieve messages sent by specific members.
option.FromIds = new List<string> { "id1", "id2" };
option.MsgTypes = new List();
option.MsgTypes.Add(MessageBodyType.TXT);
option.MsgTypes.Add(MessageBodyType.VIDEO);
option.StartTime = 1695720454000;
option.EndTime = 1695720554000;

SDKClient.Instance.ChatManager.FetchHistoryMessagesFromServerBy(conversationId, type, cursor, pageSize, option, new ValueCallBack>(
    onSuccess: (result) =>
    {

    },
    onError: (code, desc) =>
    {

    }
));

Search local messages sent by specific members

Since SDK v1.4.0, for a single conversation you can load messages from the local database that are sent by specific members.

Conversation conv = SDKClient.Instance.ChatManager.GetConversation(conversationId, convType);
conv.LoadMessagesWithScopeAndFromIds(keyword, timestamp, maxCount, fromIds, direction, scope, new ValueCallBack<List<Message>>(
    onSuccess: (list) => { },
    onError: (code, desc) => { }
));

Search local conversations by keyword

Since SDK v1.4.0, you can call LoadConversationMessagesWithKeyword to search across all local conversations for messages that contain a keyword. The SDK returns the matching conversation IDs and message IDs, ordered by message timestamp in ascending or descending order according to the direction parameter.

SDKClient.Instance.ChatManager.LoadConversationMessagesWithKeyword(keywords, timestamp, from, direction, scope, new ValueCallBack<Dictionary<string, List<string>>>(
    onSuccess: (result) => { },
    onError: (code, desc) => { }
));

Retrieve local messages by message ID

Since SDK v1.4.0, you can call LoadMessages to retrieve one or more messages from a single local conversation by message ID. To retrieve a single message, call LoadMessage.

List<string> messageIdList = new List<string> { "msgId1", "msgId2" };
SDKClient.Instance.ChatManager.LoadMessages(messageIdList, conversationId, new ValueCallBack<List<Message>>(
    onSuccess: (messages) => { },
    onError: (code, desc) => { }
));

Pin a conversation

To keep track of an important conversation, you can pin it to the top of your conversation list. You can pin up to 50 conversations. The pinned state is stored on the server. In a multi-device login use-case, if you pin or unpin a conversation, other login devices will receive the CONVERSATION_PINNED or CONVERSATION_UNPINNED events.

Refer to the following code example to pin a conversation:

SDKClient.Instance.ChatManager.PinConversation(convId, isPinned, new CallBack(
    onSuccess: () =>
    {

    },
    onError: (code, desc) =>
    {

    }
));

Retrieve the pinned conversations from the server

End users can pin up to 50 conversations. After you call this API, the SDK returns the pinned conversations in the reverse chronological order of when they are pinned.

Agora Chat servers store a list of conversations that remain active in the past 7 days, regardless of Agora Chat package subscription. A conversation is considered active if it is pinned or there are new messages in a conversation.

The Limit parameter specifies the number of conversations each API call can return, from a range of 1-50. Refer to the following code example to get a list of pinned conversations from the server with pagination:

// limit: The number of sessions returned per page. The value range is [1,50].
// cursor: The cursor position to start getting data.
int limit = 10;
string cursor = "";
bool pinOnly = true; // `false`: Get the list of all conversations; `true`: Get the list of only pinned conversations.
SDKClient.Instance.ChatManager.GetConversationsFromServerWithCursor(pinOnly, cursor, limit, new ValueCallBack>(
   onSuccess: (result) =>
   {
       // Traverse the obtained conversation list
       foreach (var conv in result.Data)
       {

       }
       // The cursor for the next query
       string nextCursor = result.Cursor;
   },
   onError: (code, desc) =>
   {

   }
));

Pin a message

To pin a message to the top of a one-to-one chat, chat group, or chat room, call ChatManager#PinMessage and set the isPinned parameter to true. When the pinned status of a message changes, other members in the one-to-one chat, group or chat room conversation receive the IChatManagerDelegate#OnMessagePinChanged event. In the case of multi-device login, the updated top status is synchronized to other logged-in devices, and other devices receive the IChatManagerDelegate#OnMessagePinChanged event, respectively.

Multiple users can pin the same message to the top. The latest pinned message overwrites the earlier information. That is, the PinnedInfo user ID and pin time correspond to the last pinned message.

If the message is stored locally but deleted on the server due to expiration, the message fails to be pinned to the top.

For a single conversation, 20 messages can be pinned to the top by default.

bool isPinned = true;
SDKClient.Instance.ChatManager.PinMessage(msgId, isPinned, new CallBack(
    onSuccess: () =>
    {
    },
    onError: (code, desc) =>
    {
    }
));

Unpin a message

To unpin a message in a one-to-one chat, chat group, or chat room, call ChatManager#PinMessage and set the isPinned parameter to false. As with pinned messages, other members of the one-to-one chat, chat group or chat room receive the IChatManagerDelegate#OnMessagePinChanged event when the pinned message is unpinned. In the case of multi-device login, the updated pin status is synchronized to other logged-in devices, and other devices receive the IChatManagerDelegate#OnMessagePinChanged event, respectively.

Any user in a one-to-one chat, group or room can unpin a message, regardless of who pinned it. After unpinning a message, PinnedBy and PinnedAt in Message#PinnedInfo are returned empty and set to 0, respectively, and the message is no longer included in the pinned message list.

bool isPinned = false;
SDKClient.Instance.ChatManager.PinMessage(msgId, isPinned, new CallBack(
    onSuccess: () =>
    {
    },
    onError: (code, desc) =>
    {
    }
));

Get pinned messages in a single conversation

You can call ChatManager#GetPinnedMessagesFromServer to get the pinned messages from a single conversation from the server. The SDK returns messages in the reverse order of pinning.

If a message expires on the server or the user deletes it unilaterally from the server after pinning, such user will not be able to pull it when pulling roaming messages. However, this user and other users will be able to pull this message from the pinned message list.If the user withdraws a message after pinning, the message will be removed from the server; other users will not be able to pull it when they pull the pinned message list from the server.

SDKClient.Instance.ChatManager.GetPinnedMessagesFromServer(convId, new ValueCallBack>(
    onSuccess: (list) => {
        foreach (var it in list)
        {
            // Traverse the message list
        }
    },
    onError: (code, desc) => {
    }
));

Get pinned details of a single message

You can call PinnedInfo to get the pinned details of a single message.

  • If the message is pinned, this class returns the time of pinning and the user ID of the user who has pinned it.
  • If the message is not pinned, then PinnedBy is returned empty and PinnedAt is set to 0.
// ...
const msg: ChatMessage;
const info = await msg.getPinInfo;
// todo: Get the pin information of the message

Delete historical messages from the server unidirectionally

Call RemoveMessagesFromServer to delete historical messages one way from the server. You can remove a maximum of 50 messages from the server each time. Once the messages are deleted, you can no longer retrieve them from the server. The deleted messages are automatically removed from your local device. Other chat users can still get the messages from the server.

SDKClient.Instance.ChatManager.RemoveMessagesFromServer(convId, ctype, time, new CallBack(
    onSuccess: () =>
    {
    },
    onError: (code, desc) =>
    {
    }
));
SDKClient.Instance.ChatManager.RemoveMessagesFromServer(convId, ctype, msgList, new CallBack(
    onSuccess: () =>
    {
    },
    onError: (code, desc) =>
    {
    }
));

Call DeleteConversationFromServer to delete conversations and their historical messages unidirectionally from the server. After the conversations and messages are deleted from the server, you can no longer get them from the server. The deleted conversations still exist on your local device, but the messages are automatically removed from the device. Other chat users can still get the conversations and their historical messages from the server.

SDKClient.Instance.ChatManager.DeleteConversationFromServer(conversationId, conversationType, isDeleteServerMessages, new CallBack(
    onSuccess: () =>
    {
    },
    onError: (code, desc) =>
    {
    }
));

Next steps

After implementing retrieving messages, you can refer to the following documents to add more messaging functionalities to your app: