This project, available from GitHub, includes the index of all packages available in the xPacks repository.
The URL of the index (to be configured in the xPacks Manager), is:
http://xpacks.github.io/index/xindex.json
Currently the index should point to each package xpack.json file (usually to a raw GitHub location).
To simplify maintenance, the index intentionally omits versions, so the index needs to be updated only when new packages are added, or, more rarely, when packages change location or are deleted; more importantly, it does not need to be updated after each and any individual package gets a new release.
The xPacks Manager must read this index, then read the individual package files to get the up-to-date list of releases.