A plurality of application servers hosts a plurality of business applications. A plurality of Application Program Interface (API) servers host a plurality of APIs to provide programmatic access to the plurality of business applications, each of the APIs configured to receive request messages compiled by a remote client application. First and second request messages targeted to first and second APIs have at least one common data component. The first request message includes a first payload specific to the first targeted API and the second request message includes a second payload specific to the second targeted API, the first payload and the second payload each comprise a reusable identified schema definition specific to the targeted API.