OpenAPI Specification (OAS) 3 introduced the concept of Server Variables, allowing for configurable parts of an API's URL, and this feature is now supported in API Explorer for users utilizing JWT Login. Server Variables enable API consumers to change specific segments of a URL, such as {username}, {port}, and {basePath}, enhancing customization for different users. The recent update has added support for enums and manual entry of Server Variables, which facilitates the creation of unique URLs for customers while maintaining a default setup for those not logged in. Although there are some limitations, such as lack of support for manually defined APIs within ReadMe, the feature represents a significant step forward in API customization, with further improvements being open for discussion with ReadMe's support team.