1. A server for validating input using a unified rule set, the server comprising: one or more processors configured to execute one or more modules of an application programming interface (API); and a memory storing the one or more modules of the API, the API comprising: the unified rule set comprising: a first set of input validation rules including rules that are to be executed by the API, and a second set of input validation rules including rules that are to be executed by a first component downward from the API.