Mysterious Custom Integration sync error: "Document can't have '.' in field names"

I have logged and checked every packet that my custom integration app sends to Fibery, and found that:

  • The only JSON key in containing a period, in any packet that was sent from the integration app, was in the pagination section of data endpoint responses, part of an email address:

I know this isn’t the real issue because this occurs elsewhere without any problem (in the pagination section).

I have analyzed every packet sent by my integration app –
Here is the uniquified list of every single JSON key from every single packet sent by the integration app:

"Created_By z":

ALL of these keys also occur in syncs that do not cause any issues.

So I suspect the error message is not accurate. Please tell me - what does it actually mean?

The only thing I can see in the data that looks even close is that some “name” fields include a period – could that be an issue??

Hello, @Matt_Blais

Please don’t use “.” in field names of nextPageConfig. It is not allowed by our sync api. Email has “.” so please don’t use the email as a field name for config.


Apparently this really was the issue – now that I filter out “.” from nextPageConfig keys, the error has stopped occurring.

This is very odd, since I have been using this format for over a year without any issues until recently… and then somewhat randomly.