Message Persistence API for PubNub JavaScript SDK

The message persistence service 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, 3, 5, 7, 15, or 30 days, and Forever.

You can retrieve the following:

  • Messages
  • Message actions
  • Files (using Files 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 add-on

This method requires that the Message Persistence add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

Description

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 storage.

Method(s)

To run Fetch History, you can use the following method(s) in the JavaScript V4 SDK:

pubnub.fetchMessages({
channels: Array<string>,
count: number,
includeMessageType: boolean,
includeUUID: boolean,
includeMeta: boolean,
includeMessageActions: boolean,
start: string,
end: string
})
ParameterTypeRequiredDefaultDescription
Operation ArgumentsHashYesA hash of arguments.
channelsArray<string>YesSpecifies channels to return history messages from. Maximum of 500 channels are allowed.
countnumberOptional100 or 25Specifies the number of historical messages to return per channel. Default is 100 per single channel and 25 per multiple channels.
includeMessageTypebooleanOptionaltruePass true to receive the message type with each history message.
includeUUIDbooleanOptionaltruePass true to receive the publisher uuid with each history message.
includeMetabooleanOptionalWhether message meta information should be fetched or not.
includeMessageActionsbooleanOptionalWhether message added message actions should be fetched or not. Throws an exception in case if API called with more than one channel. Truncation will happen if 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.
startstringOptionalTimetoken delimiting the start of time slice (exclusive) to pull messages from.
endstringOptionalTimetoken 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

Retrieve the last message on a channel:

try {
const result = await pubnub.fetchMessages({
channels: ["ch1"],
start: "15343325214676133",
end: "15343325004275466",
count: 1,
});
} catch (status) {
console.log(status);
}

Response

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

//Example of response
{
"channels":{
"my-channel":[
{
"message":"message_1",
"timetoken":"15483367794816642",
"uuid":"my-uuid",
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Other Examples

Fetch messages with metadata and actions

pubnub.fetchMessages(
{
channels: ['my_channel'],
stringifiedTimeToken: true,
includeMeta: true,
includeMessageActions: true,
},
function (status, response) {
// handle status, response
}
);

Fetch messages with metadata and actions Response

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

// Example of response
{
"channels":{
"my_channel":[
{
"timetoken":"15741125155552287",
"message":{
"text":"Hello world!",
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Delete Messages from History

Requires Message Persistence add-on

This method requires that the Message Persistence add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

Description

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 V4 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.

ParameterTypeRequiredDescription
Operation ArgumentsHashYesA hash of arguments.
channelstringYesSpecifies channel messages to be deleted from history.
startstringOptionalTimetoken delimiting the start of time slice (exclusive) to delete messages from.
endstringOptionalTimetoken delimiting the end of time slice (inclusive) to delete messages from.

Basic Usage

try {
const result = await pubnub.deleteMessages({
channel: "ch1",
start: "15088506076921021",
end: "15088532035597390",
});
} catch (status) {
console.log(status);
}

Response

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

Other Examples

Delete specific message from a channel's storage

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.

pubnub.deleteMessages(
{
channel: 'ch1',
start: '15526611838554309',
end: '15526611838554310'
},
(result) => {
console.log(result);
}
);

Message Counts

Requires Message Persistence add-on

This method requires that the Message Persistence add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

Description

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 V4 SDK:

pubnub.messageCounts({
channels: Array<string>,
channelTimetokens: Array<string>
})
ParameterTypeRequiredDefaultDescription
Operation ArgumentsHashYesA hash of arguments.
channelsArray<string>YesThe channels to fetch the message count
channelTimetokensArray<string>YesList 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 PNStatuswith an error flag.

Basic Usage

try {
const result = await pubnub.messageCounts({
channels: ["chats.room1", "chats.room2"],
channelTimetokens: ["15518041524300251"],
});
} catch (status) {
console.log(status);
}

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

try {
const result = await pubnub.messageCounts({
channels: ["ch1", "ch2", "ch3"],
channelTimetokens: [
"15495750401727535",
"15495750401727536",
"15495750401727537",
],
});

console.log(response);
} catch (status) {
// handle error
}

History (deprecated)

Requires Message Persistence add-on

This method requires that the Message Persistence add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

Alternative method

This method is deprecated. Use fetch history instead.

Description

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 V4 SDK

pubnub.history({
channel: string,
reverse: boolean,
count: number,
stringifiedTimeToken: boolean,
includeMeta: boolean,
start: string,
end: string
})
ParameterTypeRequiredDefaultDescription
Operation ArgumentsHashYesA hash of arguments.
channelstringYesSpecifies channel to return history messages from.
reversebooleanOptionalfalseSetting 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.
countnumberOptional100Specifies the number of historical messages to return. Default/Maximum is 100.
stringifiedTimeTokenbooleanOptionalfalseIf 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.
includeMetabooleanOptionalWhether message meta information should be fetched or not.
startstringOptionalTimetoken delimiting the start of time slice (exclusive) to pull messages from.
endstringOptionalTimetoken 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"
},
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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;
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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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