This specification defines the interface between the buildpack execution environment, referred to as the lifecycle, and a platform that supports it. This API is used by platform implementors.
A stack defines two OCI images: a build image and a run image. The build image is used to run the buildpack lifecycle, and the run image is the base image the final exported image will be built upon.
For more information see Working with stacks.
Buildpacks are stored on the filesystem as unarchived files such that:
You can read the complete Platform API specification on Github.