So I have spent the majority of my evening trying to get this to work and frustrating my brain.
I have been able to add the webhooks and connections successfully, however when running the connection to see if it will send the contact data over I get "Runtime Error: 400" on Constant Contact's side.
I have tried to do it with the address fields I need to have added and without, and the same for the custom fields, but it still has the same results.
I then thought I would try Zapier, however I haven't been able to see the option to add more fields for it to pass data to (unless I am missing something in the new interface).
Here is a screen shot of the error I get, which doesn't tell me much.
Thank you for reaching out to Constant Contact API Developer Support. My team is here to assist outside software developers with questions about building into Constant Contact's API.
It looks like we've already reached out to you via email regarding this issue to request some additional information in order to assist with troubleshooting, but here is the information provided for visibility on the forum:
In regards to the 400 error, that's often due to malformed data or a data validation error. Just so we can research and test the issue further, would you be able to email us the body coding you're using to add those fields into Constant Contact?
If you haven't received our email reply, please let us know via email at firstname.lastname@example.org, and reference case number 27790342.