Persistent Identifiers

A persistent identifier is an identifier that is intended to be long-lived. FamilySearch provides persistent identifiers for the following resources:

• Persons in the FamilySearch Family Tree
• Personas in the FamilySearch Historical Records Archive
• Records in the FamilySearch Historical Records Archive
• Record Artifacts such as images of documents

When a persistent identifier is provided for a resource, it means that FamilySearch has made a long-term commitment to maintain that identifier. This means that requests for the resource using the persistent identifier will always resolve to that resource. As such, it is recommended that the persistent identifier be used when storing references to that resource. The resource may support several media types and will respond accordingly (text/html), (application/*xml), (application/*json).
Note While FamilySearch commits to maintaining the identifier, there are no promises made about the state of the resource. Clients accessing the resource using the persistent identifier may find that the resource has been moved, deleted or restricted. GEDCOM X defines a way to provide persistent identifiers using an Identifier of type http://gedcomx.org/Persistent. The following code snippets provide examples for how the persistent identifier is provided on a person using GEDCOM X:

XML

<gedcomx ...>
  <person>
    ...
    <identifier type="http://gedcomx.org/Persistent">https://familysearch.org/ark:/61903/4:1:KW8W-RF8</identifier>
    ...
  </person>
</gedcomx>

JSON

{
  "persons" : [{
    ...
    "identifiers" : {
      "http://gedcomx.org/Persistent" : ["https://familysearch.org/ark:/61903/4:1:KW8W-RF8"]
    }
    ...
  }]
}

The Archival Resource Key (ARK)

FamilySearch provides the persistent identifier as an Archival Resource Key (ARK). For more information about the ARK, see the ARK specification or the ARK wikipedia article.

FamilySearch ARK Decorations

Because the ARK is a URI, it can be used by a Web browser as a permanent "bookmark" for the resource. The ARK is the recommended way to direct the user in a Web browser to the resource on the familysearch.org website.

FamilySearch currently supports the following query parameters as "decorations" that may be applied to the ARK. These decorations mostly apply when using the ARK to direct a Web browser. Also, the decorations are not included as part of FamilySearch's long-term commitment, meaning FamilySearch makes no long-term commitment to maintaining the decorations.