An Application Programming Interface (API) is a set of subroutine definitions, protocols, and tools for building computer applications. APIs allow developers to integrate applications, such as Scuba, with their technologies by only exposing objects or actions the developer needs.

For web development, an API is usually a set of Hypertext Transfer Protocol (HTTP) request messages, combined with response messages, typically in an Extensible Markup Language (XML) or JavaScript Object Notation (JSON) format. 

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