ECC part 3 will provide an Interoperability Model@ which will enable an eService compliant with technical requirements@ to interoperate with different implementations of the European Citizen Card. This Interoperability model will be developed as follows: ?? starting from the ECC part 2@ part 3 of the ECC series will provide additional technical specifications for a middleware architecture based on ISO/IEC 24727. This middleware will provide an API to an eService as per ISO/IEC 24727-3; ?? a set of additional API provide the middleware stack with means to facilitate ECC services; ?? a standard mechanism for the validation of the e-ID credential stored in the ECC and retrieved by the service. In order to support the ECC services over an ISO/IEC 24727 middelware configuration@ this part of the standard specifies the following: ?? a set of mandatory requests to be supported by the middleware implementation based on ISO/IEC 24727; ?? data set content for interoperability to be personalized in the ECC; ?? two middleware architecture solutions: one based on a stack of combined ISO/IEC 24727 configurations and the other based on Web Service configuration; ?? a Global Profile featuring the guidelines for card-applications to fit in ISO/IEC 24727 framework.