standalone library/tool to query commit-graph?

[Karl Ostmo <kostmo@xxxxxxxxx>]

After producing the file ".git/objects/info/commit-graph" with the
command "git commit-graph write", is there a way to answer queries
like "git merge-base --is-ancestor" without having a .git directory?
E.g. is there a library that will operate on the "commit-graph" file
all by itself?

Thanks,
Karl