# Message history (Beta) (/en/realtime-media/rtm/build/send-and-receive-messages/message-history/android)

> For AI agents: see the complete documentation index at [llms.txt](/llms.txt).

The Signaling message history feature allows you to store messages when publishing them to a channel. For example, if a user joins a channel midway through a conversation, you can retrieve messages that were published before the user joined. You can configure the message retention period for each project, ranging from 1 day to permanent storage.

    When a message is published, it is stored using the channel name and the message timestamp. You can use this information to retrieve historical messages.

    <CalloutContainer type="info">
      <CalloutDescription>
        The historical message feature is currently available for User Channels and Message Channels, but not for Stream Channels.
      </CalloutDescription>
    </CalloutContainer>

    ## Prerequisites [#prerequisites-1]

    Before implementing this feature, ensure that you have:

    * Integrated the Signaling SDK in your project, and implemented the framework functionality from the [SDK quickstart](../../index) page.
    * Enabled the message history feature by contacting [support@agora.io](mailto\:support@agora.io). You can request a storage duration of 1, 7, 30, 90, or 365 days, or opt for permanent storage.

      <CalloutContainer type="info">
        <CalloutDescription>
          Changes to storage duration only affect future messages.
        </CalloutDescription>
      </CalloutContainer>

    ## Implement message history [#implement-message-history-1]

    This section shows how to store and retrieve messages from history.

    ### Store messages [#store-messages-1]

    To store a message on the server, set `setStoreInHistory` to `true` in the `publish()` method. The following example shows the minimum code to store a message published to a message channel:

    ```java
    PublishOptions options = new PublishOptions();
    options.setCustomType("custom type");
    options.setStoreInHistory(true);

    String channelName = "chatRoom";
    String message = "Hello world!";
    rtm.publish(channelName, message, options, new ResultCallback<Void>() {
        @Override
        public void onSuccess(Void responseInfo) {
            log(CALLBACK, "send message success");
        }

        @Override
        public void onFailure(ErrorInfo errorInfo) {
            log(ERROR, errorInfo.toString());
        }
    });
    ```

    To store a message in the history of a user channel, use the same parameter:

    ```java
    PublishOptions options = new PublishOptions();
    options.setChannelType(RtmChannelType.USER);
    options.setCustomType("custom type");
    options.setStoreInHistory(true);

    String userId = "Tony";
    String message = "Hello world!";
    rtm.publish(userId, message, options, new ResultCallback<Void>() {
        @Override
        public void onSuccess(Void responseInfo) {
            log(CALLBACK, "send message success");
        }

        @Override
        public void onFailure(ErrorInfo errorInfo) {
            log(ERROR, errorInfo.toString());
        }
    });
    ```

    ### Retrieve messages [#retrieve-messages-1]

    The SDK provides the `getMessages()` method to retrieve up to 100 history messages at a time. You can filter messages by setting the `start` and `end` parameters to define a time range. To retrieve only the most recent messages, such as those sent between the last offline time and now, set only the `end` parameter.

    The following example retrieves the latest 50 messages sent before a specific time:

    ```java
    GetHistoryMessagesOptions options = new GetHistoryMessagesOptions();
    options.setMessageCount(50);
    options.setEnd(1688978391800);

    String channelName = "chatRoom";
    rtm.getHistory().getMessages(channelName, RtmChannelType.MESSAGE, options, new ResultCallback<GetMessagesResult>() {
        @Override
        public void onSuccess(GetMessagesResult result) {
            log(CALLBACK, "get history messages! new start: " + result.getNewStart());
            for (HistoryMessage message : result.getMessageList()) {
                log(INFO, message.toString());
            }
        }

        @Override
        public void onFailure(ErrorInfo errorInfo) {
            log(ERROR, errorInfo.toString());
        }
    });
    ```

    The `result` includes a `newStart` field, which indicates whether there are unread messages in the history:

    * If `newStart` is `0`, all messages have been retrieved.
    * If `newStart` is not `0`, use this value as the new `start` parameter in the next `getMessages()` call to continue retrieving messages.

    The following use-cases show how to specify the `start` and `end` parameters to retrieve messages in a specific range:

    #### Retrieve before a start timestamp [#retrieve-before-a-start-timestamp-1]

    | Parameter | Behavior                                                                                |
    | --------- | --------------------------------------------------------------------------------------- |
    | `start`   | Returns messages sent before the specified timestamp. The timestamp itself is excluded. |

    ```text
    Timeline:
    [Older messages] ------------ start timestamp ------------ [Newer messages]
    [             ←-- n messages]
    ```

    #### Retrieve messages up to an end timestamp [#retrieve-messages-up-to-an-end-timestamp-1]

    | Parameter | Behavior                                                                             |
    | --------- | ------------------------------------------------------------------------------------ |
    | `end`     | Returns the n most recent messages sent up to and including the specified timestamp. |

    ```text
    Timeline:
    [Older messages] ------------ end timestamp ------------ [Newer messages]
                                           [  ←-- n messages]
    ```

    #### Retrieve messages between two timestamps [#retrieve-messages-between-two-timestamps-1]

    | Parameter | Behavior                                                  |
    | --------- | --------------------------------------------------------- |
    | `start`   | Returns messages sent before this timestamp (excluded).   |
    | `end`     | Returns messages sent up to and including this timestamp. |

    ```text
    Timeline:
    [Older messages] ---- end timestamp ------------ start timestamp ---- [Newer messages]
                                   [ ←-- n messages]
    ```