@hayk Grapher is going to be worked on and have 1.3 launched before end of 2017.
Regarding your question, try refactoring userId to _id. You could write a simple migration script with $rename modifier . Custom field names for meta links are not currently supported. The rest is what @herteby said.
Please read the guide completely! Most people dive directly into the API and they have no clue what’s going on , + I totally agree, the docs need some love, and they will receive it.
@diaconutheodor thanks for the suggestion.
I really like the idea of the grapher but for now it seems hard for me to grasp it on a more practical level.
So I think having detailed docs and guides will be very helpful. I’ll make sure to submit issues, at least I can I help you that way. Thanks.