Application programme interface meaning

An application programme interface (api) is a documented set of rules, specifications and tools that enable one software system or device to call the functions or access the data of another. In legal practice it arises in technology contracts, IP licensing and procurement, where it determines interoperability, access rights, service levels, security and change control. The term is descriptive rather than statutory in the UK and Ireland, but has been considered in case law on copyright and interoperability (for example, SAS Institute v World Programming) and interacts with statutory exceptions permitting observation, study, testing and limited decompilation to achieve interoperability (CDPA 1988 in the UK; Irish implementations of the EU Software Directive). In broadcasting and consumer electronics, it can denote software in a receiver or set-top box that interprets commands (for example, where to display graphics), enabling the same application to run across different receiver designs without rewriting. Key legal issues include ownership and licensing of API specifications and SDKs, confidentiality of documentation and keys, restrictions on reverse engineering, data protection where personal data is exposed via APIs, and competition or sectoral rules mandating open APIs (for example, UK Open Banking; PSD2 in Ireland). Usage and treatment are broadly consistent across England...