Message Persistence API for Go SDK

Message Persistence gives you real-time access to the history of messages published to PubNub. Each message is timestamped to the nearest 10 nanoseconds and stored across multiple availability zones in several geographic locations. You can encrypt stored messages with AES-256 so they are not readable on PubNub’s network. For details, see Message Persistence.

You control how long messages are stored through your account’s retention policy. Options include: 1 day, 7 days, 30 days, 3 months, 6 months, 1 year, or Unlimited.

You can retrieve the following:

• Messages
• Message reactions
• Files (using the File Sharing API)

Fetch history

Requires Message Persistence

Enable Message Persistence for your key in the Admin Portal. See how to enable add-on features.

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

You can control how messages are returned and in what order:

• If you specify only the start parameter (without end), you receive messages older than the start timetoken.
• If you specify only the end parameter (without start), you receive messages from that end timetoken and newer.
• If you specify both start and end, you retrieve messages between those timetokens (inclusive of the end value).

You can receive up to 100 messages for a single channel, or 25 messages per channel when querying multiple channels (up to 500 channels). If more messages match the time range, make iterative calls and adjust the start timetoken to page through the results.

Method(s)

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

1pn.Fetch().
2    Channels(channels).
3    Count(count).
4    Start(start).
5    End(end).
6    IncludeMeta(bool).
7    IncludeMessageType(bool).
8    IncludeUUID(bool).
9    IncludeMessageActions(bool).
10    IncludeCustomMessageType(bool).
11    QueryParam(queryParam).
12    Execute()

* required

Parameter	Description
Channels * Type: string Default: n/a	Specifies channelsto return history messages. Maximum of 500 channels are allowed.
Count Type: int Default: 100 or 25	Specifies the number of historical messages to return. Default and maximum value is 100 for a single channel, 25 for multiple channels, and 25 when IncludeMessageActions is true.
Start Type: int64 Default: n/a	Timetoken delimiting the start of time slice (exclusive) to pull messages from.
End Type: int64 Default: n/a	Timetoken delimiting the end of time slice (inclusive) to pull messages from.
IncludeMeta Type: bool Default: false	Whether meta (passed when Publishing the message) should be included in response or not.
IncludeMessageType Type: bool Default: true	Pass true to receive the message type with each history message.
IncludeUUID Type: bool Default: true	Pass true to receive the publisher uuid with each history message.
IncludeMessageActions Type: bool Default: false	Whether MessageActions should be included in response or not. If true, the method is limited to one channel and 25 messages only.
IncludeCustomMessageType Type: bool Default: n/a	Indicates whether to retrieve messages with the custom message type. For more information, refer to Retrieving Messages.
QueryParam Type: map[string]string Default: nil	QueryParam accepts a map, the keys and values of the map are passed as the query string parameters of the URL called by the API.

Truncated response

If you fetch messages with message actions, the response may be truncated when internal limits are reached. If truncated, a more property is returned with additional parameters. Make iterative calls to history, adjusting the parameters to fetch more messages.

Sample code

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 the last messages on a channel:

1

Returns

The Fetch() operation returns a FetchResponse object which contains the following field:

Field	Type	Description
Messages	map[string][]FetchResponseItem	Map where keys are channel names and values are arrays of message items.

Each FetchResponseItem contains:

Field	Type	Description
Message	interface	Message from history.
Timetoken	string	Timetoken of the message.
Meta	interface	The metadata (if sent with the message).
MessageType	int	Message type. Returns 4 for file messages.
UUID	string	Publisher UUID of the message.
MessageActions	map[string]PNHistoryMessageActionsTypeMap	Message actions associated with the message. Details of type PNHistoryMessageActionsTypeMap are described below.
File	PNFileDetails	File details if the message contains a file.
Error	error	Decryption error if message couldn't be decrypted.

PNHistoryMessageActionsTypeMap

Field	Type	Description
ActionsTypeValues	map[string][]PNHistoryMessageActionTypeVal	Details of type PNHistoryMessageActionTypeVal are described below.

PNHistoryMessageActionTypeVal

Field	Type	Description
UUID	string	The UUID of the publisher.
ActionTimetoken	string	The publish timetoken of the action.

Status response

Field	Type	Description
Error	error	Error information, if any
Category	StatusCategory	Status category of the operation
Operation	OperationType	Operation type
StatusCode	int	HTTP status code
TLSEnabled	bool	Whether TLS is enabled
UUID	string	UUID of the client
AuthKey	string	Auth key used
Origin	string	Origin server
OriginalResponse	string	Raw response from server
Request	string	Request that was sent
AffectedChannels	[]string	Channels affected by this operation
AffectedChannelGroups	[]string	Channel groups affected by this operation

Other examples

Fetch with metadata

1

Fetch with time range

1

Fetch from multiple channels

1

Delete messages from history

Requires Message Persistence

Enable Message Persistence for your key in the Admin Portal. See how to enable add-on features.

Remove messages from the history of a specific channel.

Required setting

To accept delete-from-history requests, enable the Delete-From-History setting for your key in the Admin Portal and initialize the SDK with a secret key.

Method(s)

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

1pn.DeleteMessages().
2    Channel(channel).
3    Start(start).
4    End(end).
5    QueryParam(queryParam).
6    Execute()

* required

Parameter	Description
Channel * Type: string	Specifies channels to delete messages from.
Start Type: int64	Timetoken delimiting the start of time slice (inclusive) to delete messages from.
End Type: int64	Timetoken delimiting the end of time slice (exclusive) to delete messages from.
QueryParam Type: map[string]string	QueryParam accepts a map, the keys and values of the map are passed as the query string parameters of the URL called by the API.

Sample code

1

Returns

The DeleteMessages() operation returns an empty HistoryDeleteResponse struct. Check the status response to verify success.

Status response

Field	Type	Description
Error	error	Error information, if any
Category	StatusCategory	Status category of the operation
Operation	OperationType	Operation type
StatusCode	int	HTTP status code
TLSEnabled	bool	Whether TLS is enabled
UUID	string	UUID of the client
AuthKey	string	Auth key used
Origin	string	Origin server
OriginalResponse	string	Raw response from server
Request	string	Request that was sent
AffectedChannels	[]string	Channels affected by this operation
AffectedChannelGroups	[]string	Channel groups affected by this operation

Other examples

Delete specific message from history

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.

1

Message counts

Requires Message Persistence

Enable Message Persistence for your key in the Admin Portal. See how to enable add-on features.

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

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 Go SDK:

1pn.MessageCounts().
2    Channels(channels).
3    ChannelsTimetoken(channelsTimetoken).
4    QueryParam(queryParam).
5    Execute()

* required

Parameter	Description
Channels * Type: []string Default: n/a	The channels to fetch the message count
ChannelsTimetoken * Type: []int64 Default: nil	Array 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.
QueryParam Type: map[string]string Default: nil	QueryParam accepts a map, the keys and values of the map are passed as the query string parameters of the URL called by the API.

Sample code

1

Returns

The MessageCounts() operation returns a MessageCountsResponse object which contains the following field:

Field	Type	Description
Channels	map[string]int	Channel names with message counts. Channels without messages have a count of 0. Channels with 10,000 messages or more have a count of 10000.

Status response

Field	Type	Description
Error	error	Error information, if any
Category	StatusCategory	Status category of the operation
Operation	OperationType	Operation type
StatusCode	int	HTTP status code
TLSEnabled	bool	Whether TLS is enabled
UUID	string	UUID of the client
AuthKey	string	Auth key used
Origin	string	Origin server
OriginalResponse	string	Raw response from server
Request	string	Request that was sent
AffectedChannels	[]string	Channels affected by this operation
AffectedChannelGroups	[]string	Channel groups affected by this operation

Other examples

Retrieve count of messages using different timetokens for each channel

1

History (deprecated)

Requires Message Persistence

Enable Message Persistence for your key in the Admin Portal. See how to enable add-on features.

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 Go SDK:

1pn.History().
2    Channel(string).
3    Reverse(bool).
4    IncludeTimetoken(bool).
5    IncludeMeta(bool).
6    Start(int64).
7    End(int64).
8    Count(int).
9    QueryParam(queryParam).
10    Execute()

* required

Parameter	Description
Channel Type: string Default: n/a	Specifies channel to return history messages from.
Reverse Type: bool Default: false	Setting to true will traverse the time line in reverse starting with the oldest message first.
IncludeTimetoken Type: bool Default: false	Whether event dates timetokens should be included in response or not.
IncludeMeta Type: bool Default: false	Whether meta (passed when Publishing the message) should be included in response or not.
Start Type: int64 Default: n/a	Timetoken delimiting the start of time slice (exclusive) to pull messages from.
End Type: int64 Default: n/a	Timetoken delimiting the end of time slice (inclusive) to pull messages from.
Count Type: int Default: 100	Specifies the number of historical messages to return.
QueryParam Type: map[string]string Default: nil	QueryParam accepts a map, the keys and values of the map are passed as the query string parameters of the URL called by the API.

tip

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.

Sample code

Retrieve the last 100 messages on a channel:

1

Returns

The History() operation returns a HistoryResponse object which contains the following fields:

Field	Type	Description
Messages	[]HistoryResponseItem	Array of messages. See HistoryResponseItem for more details.
StartTimetoken	int64	Start timetoken of the returned messages.
EndTimetoken	int64	End timetoken of the returned messages.

HistoryResponseItem

Field	Type	Description
Timetoken	int64	Timetoken of the message.
Message	interface	The message content.
Meta	interface	The metadata (if sent when publishing the message).
Error	error	Decryption error if message couldn't be decrypted.

Status response

Field	Type	Description
Error	error	Error information, if any
Category	StatusCategory	Status category of the operation
Operation	OperationType	Operation type
StatusCode	int	HTTP status code
TLSEnabled	bool	Whether TLS is enabled
UUID	string	UUID of the client
AuthKey	string	Auth key used
Origin	string	Origin server
OriginalResponse	string	Raw response from server
Request	string	Request that was sent
AffectedChannels	[]string	Channels affected by this operation
AffectedChannelGroups	[]string	Channel groups affected by this operation

Other examples

Use history() to retrieve the three oldest messages

1

Use history() to retrieve messages newer than a given timetoken

1

Use history() to retrieve messages until a given timetoken

1

History paging example

1

Include timetoken in history response

1