An application programming interface (API) is a library or structured set of software tools that provides an interface to a backend software platform, such as a social networking platform, without providing direct access to the underlying source code of the platform.

For example, Facebook™, Twitter™, Instagram™, LinkedIn™, Google Plus™, and Tumblr™ offer APIs so that developers can interface with their social networking platforms, resulting in widespread development of various social network based software applications.

For example, social gaming applications use social network APIs to access social connections and profile page data, and publish activities to user news feeds and profile pages. Using the social network API, a developer can add social features to a software application with profile, friend, status, photo, video, event, and group data from the social network platform. The software application may exchange data with the social network platform through API software tools.

A software application built using a social network application API is often tightly connected and dependent on the underlying social network platform, which gives rise to practical legal considerations.

Generally, terms of use govern how the API software tools may be legally used by the software application. Any breach of the terms of use generally provides the social network platform with the ability to deny use of the API and effectively shut down operation of the software application. A careful review of such terms of use is critical prior to any development using the API for the social network to ensure any contemplated use is in line with those terms.

Commonly, social network API terms of use require representation that the developer owns the intellectual property (IP) rights in its software and that its software does not infringe on the IP rights of others. This may require extra IP diligence by the developer. In the event of an IP dispute involving the software application, a social network platform may give deference to the IP owner pending resolution of the dispute even if a legitimate defense exists, and block the software application from interfacing with the social network platform using the API as a violation of terms of use.

Branding of the software application built using the API requires careful consideration of any third party trade-marks, including the social network trade-mark. Generally, the owner has exclusive of use of its trade-mark. Any software application branding may not be permitted to refer to the social network brand or another third party brand in a way that causes confusion as to the owner. Again, even if a trademark dispute is unfounded or uncertain, the social network can effectively shut down operation of the software application pending its resolution.

Copyright protects computer programs as literary works. Copying sections of software code when developing the software application may violate copyright, which in turn may violate terms of use of the API. Even if the copying is considered a fair use or fair dealing, the terms of use may require ownership of the intellectual property. In some cases, copyright protection may also extend to the library or structure set of the API. Accordingly, even developers of the social network API itself must be careful not to copy another social network API library or structured set of software tools.

Finally, patent protection may extend to particular forms of software. Independent creation may not be a defense to patent infringement so even if the developer did not intentionally copy any third party intellectual property they may be unknowingly infringing on patent rights and violating the terms of use.

Accordingly, while using an API for a social network may facilitate software development, the dependency of the software application on the underlying social network requires additional legal diligence.

Maya Medeiros (  / 416.216.4823) is a lawyer, Patent Agent, and Trade-mark Agent in the Toronto office of Norton Rose Fulbright Canada.