A web server providing access to a package archive must support the following queries:
Return a lisp form describing the archive contents. The form is a list of ’package-desc’ structures (see package.el), except the first element of the list is the archive version.
Return the long description of the package.
Return the signature for the file.
Return the file. This will be the tarball for a multi-file package, or the single file for a simple package.