Technically there is unsanctioned access (someone reverse engineered the real-time APIs [1] which I ported to Go). I think the FDA does not want easy access to real-time values so that folks can't easily recommend insulin dosing without oversight. I am personally of the opinion that it is our right to have programmatic access to the real-time data and do with it what we please.
Would love to get in touch to hear more about your long-term vision for the project!
[1] https://github.com/gagebenne/pydexcom