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API Calls showing but no contacts in Constant Contact


API Calls showing but no contacts in Constant Contact



I intergrated a Landing Page with Constant Contact and tested it loads for the API feed into constant contact, all was fine. Went live with PPC campaign with landing page and initial 5 optins came into constant contact as new contacts without a problem. Next day beyond those 5 no new ones coming in, ran about 8 tests and no new contacts showing. I checked the API report and shows 25 calls overnight and only 5 contacts showing. 


Anyone can help me find out whats happening?


Honored Contributor

Re: API Calls showing but no contacts in Constant Contact



After doing a bit of a dive into our logs, it looks like the API is returning an error 400 response. Since I'm not able to see the exact API requests, I don't know the precise cause. However, I suspect that it may be related to a change in the contact lists for the account. If the form was linked to a list that no longer exists, then the API call will fail as it's attempting to use a list that is no longer available.


If double-checking the list settings for the form does not resolve the issue, I would advise sending us an email to with as much detail as you can, and we should be able to help you find some more information!



Elijah G.
API Support Engineer

Re: API Calls showing but no contacts in Constant Contact

Hi Elijah,


No changes have occured to the lists so I will send an email.



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