TestFairy “No permissions” using REST
Yes, raw API access is a paid-plan feature available only for Startup and Enterprise packages. That's why you're getting the "no permissions" error. You should email TestFairy's support for more info.
iOS :: 'TestFairy.h' file not found
I followed the instructions and I reproduced the error. My workaround was to drag the 3 files (withou the folder) and check "Copy items if needed" checkbox. Build was successfull. You can create a "Group" and put the three files in the virtual folder after you build.