EAPI is a version defined in ebuilds and other package manager related files which informs the package manager about the file syntax and content.
The EAPI versions (and their meaning) are defined in the Package Manager Specification (PMS). Currently, EAPIs 0 through 8 are defined and officially supported. In the main Gentoo repository, EAPIs 0 to 4 are banned for new ebuilds, while 5 has been deprecated.
Commonly used eclasses often define their own set of supported EAPIs.
- Future EAPI — collects feature ideas which are being requested for inclusion in a future EAPI specification.