Useful timestamps

Most of our APIs, including Server API, Webhooks, and JavaScript agent, support useful timestamps related to a visitor in the response formats. All these timestamps are presented as ISO-8601 strings (UTC timezone, millisecond precision). The majority of popular programming languages support ISO-8601 time format in their standard libraries.

Format

That's what those timestamps look like in the responses of the corresponding APIs:

{
  // ...
  "firstSeenAt": {
    "global": "2022-03-16T11:26:45.362Z",
    "subscription": "2022-03-16T11:31:01.101Z"
  },
  "lastSeenAt": {
    "global": "2022-03-16T11:28:34.023Z",
    "subscription": null
  },
  // ...
}

Definitions

• firstSeenAt.subscription - time of the first visit of the visitor within the current application.
• firstSeenAt.global - time of the first visit of the visitor across all Fingerprint Pro accounts.
• lastSeenAt.subscription - time of the previous visit of the visitor within the current application.
• lastSeenAt.global - time of the previous visit of the visitor across all Fingerprint Pro accounts.

Those timestamps can be null. For instance, in case a completely new visitor comes,
both lastSeenAt timestamps will be equal to null, because there is no previous visit before the first visit. In case a visitor comes for the first time within your application, but has been seen within another application, lastSeenAt.subscription will be null and lastSeenAt.global won't.

You can also use the visitorFound property of the identification result to check if the visitor has ever been identified globally.