The Pending Modifications resource describes the set of pending modifications that have been defined for the FamilySearch API, including the name of the modification, a description of the modification, whether the modification is enabled for the current request, and when the modification will be activated.

A pending modification is a set of functionality that is potentially disruptive to consumers of the FamilySearch API that is scheduled to be activated on a given date. When a pending modification is enabled for a given API request, it means that the functionality defined by that modification will be applied to that request. Pending modifications may be enabled for a request by including the name of the modification in a comma-separated list as the value of a header named X-FS-Feature-Tag. A pending modification will be defined for a specified time period. At the end of the time period, the pending modification will be "activated" (i.e., enabled permanently).

Consumers of the FamilySearch API should regularly ensure that their products correctly function when each modification is enabled.