How Are Web APIs Versioned in Practice?A Large-Scale Empirical Study

Web APIs form the cornerstone of modern software ecosystems, facilitatingseamless data exchange and service integration. Ensuring the compatibilityand longevity of these APIs is paramount. This study delves into the intricaterealm of API versioning practices, a crucial mechanism for managing APIevolution. Exploring an expanded and diverse dataset of 603 293 APIs spec-ifications created during the 2015-2023 timeframe and gathered from fourdifferent sources, we examined the adoption of the following versioning prac-tices: Metadata-based, URL-based, Header-based and Dynamic versioning,with one or more versions in production. API developers use more than 50different version identifier formats to encode information about the changesintroduced with respect to the previous version (i.e., semantic versioning),about when the version was released (i.e., age versioning) and about whichphase of the API development lifecycle the version belongs (i.e., stable vs.preview releases).