Hey there Matthew, I unfortunately cannot share the GitHub repo as my team's project is confidential at this point, but this question was asked here:
 and that solution did not work for me.

I also saw it asked here :
and it was not resolved either. 

Here is what my code looks like now. In my first call, I can receive the object with no problem. In the second, I get the error:

error: '0 ,1 ,2 ,3 ,4 ,5 ,6 ,7 ,8 ,9 ,10 ,11 ,12 ,13 ,14 ,15 ,16 ,17 ,18 ,19 ,20 ,21 ,22 ,23 ,24 ,25 ,26 ,27 ,28 ,29 ,30  are not a valid field.' 

I've configured my code in various different ways, with and without the "customfields" section and via curl on my command line and it always results in a "field doesn't exist" error of some sort, even when I use basic fields like name. Any help would be greatly appreciated, as it will really help my project get into a usable state. I like your product but this has been a huge blocker to finishing our site. The same functions work on Zapier but for some reason not via this API.