The FamilySearch Genealogies API provides a database that stores non-collaborative, user-submitted genealogies. The data submitted to FamilySearch Genealogies is separate from the data in FamilySearch Family Tree. With the exception of living persons, genealogies data will be publicly visible and searchable, and can be matched against the FamilySearch Historical Records. The Genealogies data is not subject to the same constraints and certification restrictions as is data that is submitted to the FamilySearch Family Tree.
The Genealogies API is provided with the intent that the data in the FamilySearch Genealogies database will inform the collaborative research of the Family Tree and contribute to its accuracy and quality.
Like the Family Tree API, the Genealogies API conforms to the GEDCOM X specification set, but the data validation rules are generally less restrictive than are the rules of the Family Tree. For example, the Genealogies API supports more fact types and can support multiple values for facts like birth, death, burial, etc. Clients that conform to the GEDCOM X specification set can be used to access both the Family Tree API and the Genealogies API.
The FamilySearch Genealogies database is separated into multiple "trees" that can contain persons. A user can create a tree and add/update/remove persons from the tree. Relationships can be created between two persons in a tree, but are not read outside the context of the person.
For more information about the Genealogies API, refer to the Genealogies section of the API documentation.