Message Persistence API for JavaScript SDK

Message Persistence provides real-time access to the history of all messages published to PubNub. Each published message is timestamped to the nearest 10 nanoseconds and is stored across multiple availability zones in several geographical locations. Stored messages can be encrypted with AES-256 message encryption, ensuring that they are not readable while stored on PubNub's network. For more information, refer to Message Persistence.

Messages can be stored for a configurable duration or forever, as controlled by the retention policy that is configured on your account. The following options are available: 1 day, 7 days, 30 days, 3 months, 6 months, 1 year, or Unlimited.

You can retrieve the following:

  • Messages
  • Message reactions
  • File Sharing (using File Sharing API)
Supported and recommended asynchronous patterns

PubNub supports Callbacks, Promises, and Async/Await for asynchronous JS operations. The recommended pattern is Async/Await and all sample requests in this document are based on it. This pattern returns a status only on detecting an error. To receive the status errors, you must use the try...catch syntax in your code.

Fetch History​

Requires Message Persistence

This method requires that Message Persistence is enabled for your key in the Admin Portal.

This function fetches historical messages from one or multiple channels. The includeMessageActions flag also allows you to fetch message actions along with the messages.

It's possible to control how messages are returned and in what order.

  • if you specify only the start parameter (without end), you will receive messages that are older than the start timetoken
  • if you specify only the end parameter (without start), you will receive messages from that end timetoken and newer
  • if you specify values for both start and end parameters, you will retrieve messages between those timetokens (inclusive of the end value)

You will receive a maximum of 100 messages for a single channel or 25 messages for multiple channels (up to 500). If more messages meet the timetoken criteria, make iterative calls while adjusting the start timetoken to fetch the entire list of messages from Message Persistence.

Method(s)​

To run Fetch History, you can use the following method(s) in the JavaScript SDK:

pubnub.fetchMessages({
    channels: Array<string>,
    count: number,
    includeMessageType: boolean,
    includeCustomMessageType: boolean,
    includeUUID: boolean,
    includeMeta: boolean,
    includeMessageActions: boolean,
    start: string,
    end: string
})
* required
ParameterDescription
channels *
Type: Array<string>
Default:
n/a
Specifies channels to return history messages from. Maximum of 500 channels are allowed.
count
Type: number
Default:
100 or 25
Specifies the number of historical messages to return per channel. Default is 100 per single channel and 25 per multiple channels or per single channel if includeMessageActions is used.
includeMessageType
Type: boolean
Default:
true
Pass true to receive the message type with each history message.
includeCustomMessageType
Type: Boolean
Default:
n/a
Indicates whether to retrieve messages with the custom message type.

For more information, refer to Retrieving Messages.
includeUUID
Type: boolean
Default:
true
Pass true to receive the publisher uuid with each history message.
includeMeta
Type: boolean
Default:
n/a
Whether message meta information should be fetched or not.
includeMessageActions
Type: boolean
Default:
n/a
Whether message-added message actions should be fetched or not. If used, the limit of messages retrieved will be 25 per single channel. Throws an exception if API is called with more than one channel. Truncation will happen if the number of actions on the messages returned is > 25000. Each message can have a maximum of 25000 actions attached to it. Consider the example of querying for 10 messages. The first five messages have 5000 actions attached to each of them. The API will return the first 5 messages and all their 25000 actions. The response will also include a more link to get the remaining 5 messages.
start
Type: string
Default:
n/a
Timetoken delimiting the start of time slice (exclusive) to pull messages from.
end
Type: string
Default:
n/a
Timetoken delimiting the end of time slice (inclusive) to pull messages from.
Truncated response

If you fetch messages with messages actions, the number of messages in the response may be truncated when internal limits are hit. If the response is truncated, a more property will be returned with additional parameters. Send iterative calls to history adjusting the parameters to fetch more messages.

Basic Usage​

Reference code

This example is a self-contained code snippet ready to be run. It includes necessary imports and executes methods with console logging. Use it as a reference when working with other examples in this document.

Retrieve a message from a channel:



Response​

//Example of status
{
    error: false,
    operation: 'PNFetchMessagesOperation',
    statusCode: 200
}

//Example of response
{
    "channels":{
        "my-channel":[
            {
                "message":"message_1",
                "timetoken":"15483367794816642",
                "uuid":"my-uuid",
show all 23 lines

Other Examples​

Fetch messages with metadata and actions​


Fetch messages with metadata and actions Response​

Return information on message actions

To get information on actions taken on specific messages within a PubNub channel (like reactions, edits, deletions, or other custom-defined actions) use the actions object instead of the deprecated data object.

// Example of status
{
    "error": false,
    "operation": "PNFetchMessagesOperation",
    "statusCode": 200
}

// Example of response
{
    "channels":{
        "my_channel":[
            {
                "channel : "my_channel",
                "timetoken":"15741125155552287",
                "message":{
show all 40 lines

Delete Messages from History​

Requires Message Persistence

This method requires that Message Persistence is enabled for your key in the Admin Portal.

Removes the messages from the history of a specific channel.

Required setting

There is a setting to accept delete from history requests for a key, which you must enable by checking the Enable Delete-From-History checkbox in the key settings for your key in the Admin Portal.

Requires Initialization with secret key.

Method(s)​

To Delete Messages from History, you can use the following method(s) in the JavaScript SDK.

pubnub.deleteMessages({
    channel: string,
    start: string,
    end: string
})
Method behavior

The Delete Messages method behaves slightly differently than other history methods. Note that the start parameter is exclusive and the end parameter is inclusive.

* required
ParameterDescription
channel *
Type: string
Specifies channel messages to be deleted from history.
start
Type: string
Timetoken delimiting the start of time slice (exclusive) to delete messages from.
end
Type: string
Timetoken delimiting the end of time slice (inclusive) to delete messages from.

Basic Usage​


Response​

{
    error: false,
    operation: 'PNDeleteMessagesOperation',
    statusCode: 200
}

Other Examples​

Delete specific message from a Message Persistence​

To delete a specific message, pass the publish timetoken (received from a successful publish) in the End parameter and timetoken +/- 1 in the Start parameter. For example, if 15526611838554310 is the publish timetoken, pass 15526611838554309 in Start and 15526611838554310 in End parameters respectively as shown in the following code snippet.


Message Counts​

Requires Message Persistence

This method requires that Message Persistence is enabled for your key in the Admin Portal.

Returns the number of messages published on one or more channels since a given time. The count returned is the number of messages in history with a timetoken value greater than or equal to than the passed value in the channelTimetokensparameter.

Unlimited message retention

For keys with unlimited message retention enabled, this method considers only messages published in the last 30 days.

Method(s)​

You can use the following method(s) in the JavaScript SDK:

pubnub.messageCounts({
    channels: Array<string>,
    channelTimetokens: Array<string>
})
* required
ParameterDescription
channels *
Type: Array<string>
Default:
n/a
The channels to fetch the message count
channelTimetokens *
Type: Array<string>
Default:
n/a
List of timetokens, in order of the channels list. Specify a single timetoken to apply it to all channels. Otherwise, the list of timetokens must be the same length as the list of channels, or the function returns a PNStatus with an error flag.

Basic Usage​


Returns​

Message count

Channels without messages have a count of 0. Channels with 10,000 messages or more have a count of 10000.

{
    channels: {
        ch1: 49
    }
}

Status Response​

{
    error: false,
    operation: 'PNMessageCountsOperation',
    statusCode: 200
}

Other Examples​

Retrieve count of messages using different timetokens for each channel​


History (deprecated)​

Requires Message Persistence

This method requires that Message Persistence is enabled for your key in the Admin Portal.

Alternative method

This method is deprecated. Use fetch history instead.

This function fetches historical messages of a channel.

It is possible to control how messages are returned and in what order, for example you can:

  • Search for messages starting on the newest end of the timeline (default behavior - reverse = false)
  • Search for messages from the oldest end of the timeline by setting reverse to true.
  • Page through results by providing a start OR end timetoken.
  • Retrieve a slice of the time line by providing both a start AND end timetoken.
  • Limit the number of messages to a specific quantity using the count parameter.
Start & End parameter usage clarity

If only the start parameter is specified (without end), you will receive messages that are older than and up to that start timetoken value. If only the end parameter is specified (without start) you will receive messages that match that end timetoken value and newer. Specifying values for both start and end parameters will return messages between those timetoken values (inclusive on the end value). Keep in mind that you will still receive a maximum of 100 messages even if there are more messages that meet the timetoken values. Iterative calls to history adjusting the start timetoken is necessary to page through the full set of results if more than 100 messages meet the timetoken values.

Method(s)​

To run History, you can use the following method(s) in the JavaScript SDK

pubnub.history({
    channel: string,
    reverse: boolean,
    count: number,
    stringifiedTimeToken: boolean,
    includeMeta: boolean,
    start: string,
    end: string
})
* required
ParameterDescription
channel *
Type: string
Default:
n/a
Specifies channel to return history messages from.
reverse
Type: boolean
Default:
false
Setting to true will traverse the time line in reverse starting with the oldest message first.If both start and end arguments are provided, reverse is ignored and messages are returned starting with the newest message.
count
Type: number
Default:
100
Specifies the number of historical messages to return. Default/Maximum is 100.
stringifiedTimeToken
Type: boolean
Default:
false
If stringifiedTimeToken is specified as true, the SDK will return timetoken values as a strings instead of integers. Usage of setting is encouraged in JavaScript environments which perform round-up/down on large integers.
includeMeta
Type: boolean
Default:
n/a
Whether message meta information should be fetched or not.
start
Type: string
Default:
n/a
Timetoken delimiting the start of time slice (exclusive) to pull messages from.
end
Type: string
Default:
n/a
Timetoken delimiting the end of time slice (inclusive) to pull messages from.
Using the reverse parameter:

Messages are always returned sorted in ascending time direction from history regardless of reverse. The reverse direction matters when you have more than 100 (or count, if it's set) messages in the time interval, in which case reverse determines the end of the time interval from which it should start retrieving the messages.

Basic Usage​

Retrieve the last 100 messages on a channel:

try {
    const result = await pubnub.history({
        channel: "history_channel",
        count: 100, // how many items to fetch
        stringifiedTimeToken: true, // false is the default
    });
} catch (status) {
    console.log(status);
}

Response​

// Example of Status
{
    error: false,
    operation: "PNHistoryOperation",
    statusCode: 200
}

// Example of Response
{
    endTimeToken: "14867650866860159",
    messages: [
        {
            timetoken: "14867650866860159",
            entry: "[User 636] hello World"
        },
show all 21 lines

Other Examples​

Use history() to retrieve the three oldest messages by retrieving from the time line in reverse​

try {
    const result = await pubnub.history({
        channel: "my_channel",
        reverse: true, // Setting to true will traverse the time line in reverse starting with the oldest message first.
        count: 3, // how many items to fetch
        stringifiedTimeToken: true, // false is the default
    });
} catch (status) {
    console.log(status);
}

Use history() to retrieve messages newer than a given timetoken by paging from oldest message to newest message starting at a single point in time (exclusive)​

try {
    const result = await pubnub.history({
        channel: "my_channel",
        reverse: true, // Setting to true will traverse the time line in reverse starting with the oldest message first.
        stringifiedTimeToken: true, // false is the default
        start: "13406746780720711", // start timetoken to fetch
    });
} catch (status) {
    console.log(status);
}

Use history() to retrieve messages until a given timetoken by paging from newest message to oldest message until a specific end point in time (inclusive)​

try {
    const result = await pubnub.history({
        channel: "my_channel",
        stringifiedTimeToken: true, // false is the default
        end: "13406746780720711", // start timetoken to fetch
    });
} catch (status) {
    console.log(status);
}

History Paging Example​

Usage

You can call the method by passing nothing or a valid timetoken as the argument.

async function getAllMessages(initialTimetoken = 0) {
    const allMessages = [];
    let latestCount = 100;
    let timetoken = initialTimetoken;

    while (latestCount === 100) {
        const { messages, startTimeToken, endTimeToken } = await pubnub.history(
            {
                channel: "history_test",
                stringifiedTimeToken: true, // false is the default
                start: timetoken, // start timetoken to fetch
            }
        );

        latestCount = messages.length;
show all 28 lines

Fetch messages with metadata​

try {
    const result = await pubnub.history({
        channel: "my_channel",
        stringifiedTimeToken: true,
        includeMeta: true,
    });
} catch (status) {
    console.log(status);
}

Basic usage with Promises​

pubnub.history({
    channel: 'history_channel',
    reverse: true, // Setting to true will traverse the time line in reverse starting with the oldest message first.
    count: 100, // how many items to fetch
    stringifiedTimeToken: true, // false is the default
    start: '123123123123', // start timetoken to fetch
    end: '123123123133', // end timetoken to fetch
}).then((response) => {
    console.log(response);
}).catch((error) => {
    console.log(error);
});
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