If you want to create such a registry yourself, you may want to take a look at npm, the package manager of Node.js, which is open-source and very similar in scope to want you describe. Npm is both:

1. a central registry with metadata about each library:
   • name, description, keywords, homepage, author, contributors
   • version number, in principle complying with semantic versioning
   • URL of source repository (svn, git, github, gitlab, bitbucket...)
   • compatibility information (in this case it's about the versions of Node)
   • license
   • dependencies
2. a command-line tool for:
   • searching the registry
   • downloading and installing packages, recursively following their dependencies
   • publishing and updating your own packages on the registry.

See for example the page of a popular library, and the JSON file holding its metadata.

If you want to create such a registry yourself, you may want to take a look at npm, the package manager of Node.js, which is open-source and very similar in scope to want you describe. Npm is both:

1. a central registry with metadata about each library:
   • name, description, keywords, homepage, author, contributors
   • version number, in principle complying with semantic versioning
   • URL of source repository (svn, git, github, gitlab, bitbucket...)
   • compatibility information (in this case it's about the versions of Node)
   • license
   • dependencies
2. a command-line tool for:
   • searching the registry
   • downloading and installing packages, recursively following their dependencies
   • publishing and updating your own packages on the registry.

See for example the page of a popular library, and the JSON file holding its metadata.