A Research On Copyrightability And Fair Use Of API

An application programming interface(API) is a set of routines, protocols, and tools for building applications. An API expresses what functions it contains and how other programs can invoke them. A program that embody the functions of a certain API are usually called an implementation of API. Since the characteristics of software engineering, APIs are widely existed in operation systems, middlewares, applications, etc. In history, due to the compatibility concern, reimplementing an API are considered a proper requirement. Though reimplementing of APIs will produce different expressions of functions, but APIs themselves have to be copied. Because of this, whether APIs are copyrightable became a controversial issue. This thesis will analyze copyrightability of APIs, and then, it will also discuss how to constrain copyright protection of APIs by way of fair use, prevent this sort of protection from impeding software innovation. In the end, this thesis will bring forward some advises about copyright protection of APIs.In order to analyze copyrightability of APIs, it could be divided into two parts, literal and non-literal elements. Literal elements of APIs are mainly constituted by individual lines of declaring code. Respect to single line declaring code, it could be broken down into technologic description elements and name elements. Because of merger doctrine, technologic description elements are excluded the scope of copyright protection. For the reason of shortage of originality, name elements are also unprotectable. In addition, there is no choice space in selecting and arranging the both parts. Therefore, single line declaring code is unprotectable.Copyrightability of APIs is mainly reflected in their structure, non-literal elements. Declaring code forms an API’s structure, and this structure reflects the structure of an API’s implement. Because structure of software could be protected by copyright, APIs is copyrightable.Though APIs are used to invoke software function, they shouldn’t be classified among methods of operation. Otherwise, the theory of copyright protection of software will not be self-affirming. APIs are expressions of methods of operation.Opponents argue that copyrightable APIs will not be allowed to freely reimplement and this will threaten the innovation and development of the information industry. But these negative effects may be overestimated, market will guide the utilization of APIs. Furthermore, fair use defenses can relief the tension between copyright protection of APIs and software innovation.