Summary and Outlook This document specifies the interfaces for a single Asset Administration Shell and its Submodels, as well as for a repository of Asset Administration Shells. Additionally, infrastructural interfaces like Registry and Discovery of a set of Asset Administration Shells are specified. All interfaces are specified in a technology-neutral way before defining technology-specific APIs. In this version of the specification, HTTP/REST APIs are defined and mapped to the technology-neutral specification as a frontrunner. In subsequent versions of this specification, APIs using other technologies are planned to be supported, e.g. gRPC or MQTT. Additionally, further interfaces, service specifications, and profiles may be defined.