@averagewall, check out openknowledgemaps.org

Also, citeseerx and crossref are your friends.

Pubmed central similarly has the ability to return much of this citation data programatically (for certain scientific subdomains)

If you're passionate about prototyping such a service, let me know and we can get you an invite to the Archive Labs slack (we're a non-profit, volunteer-run community which incubates open access and public good projects). Literate, reproducible research and knowledge + citation graphs are two of our emphases.

Good luck