409 conflict error even when passing in unmodified data

[WalterB41]

I successfully replicated this problem using the API tester:

I use the "Retrieve a contact with a specified Contact ID" endpoint:

https://api.constantcontact.com/v2/contacts/xxxxx?api_key=yyyyyy

In most cases, I can copy the result body and paste it in (unmodified!) as the request body for the endpoint "Modify a contact with specific Contact ID"

https://api.constantcontact.com/v2/contacts/xxxxx?action_by=ACTION_BY_OWNER&api_key=yyyyyy

In about 90% of test cases, this works successfully.  In the remaining 10%, I get:

Response StatusSelect content

409 Conflict

Response HeadersSelect content

Cache-Control: private, no-cache, no-store, max-age=0, must-revalidate, no-cache="Set-Cookie"
Content-Type: application/json
Date: Thu, 17 Mar 2016 01:09:53 GMT
Pragma: no-cache
Server: Apache
Vary: Accept-Encoding,User-Agent
X-Mashery-Responder: prod-j-worker-us-east-1e-114.mashery.com
X-Powered-By: 
Content-Length: 130
Connection: keep-alive

Response BodySelect content

[{
    "error_key": "http.status.conflict",
    "error_message": "There was a conflict between the supplied data and the existing resource."
}]

 Is there a reason why this would be?  My actual use case is more complex, but I created this simple test case to eliminate any other variables.

Jon

[Elijah_G · Accepted solution]

Hello,

In the case of a conflict when sending unmodified data, the most likely cause is a contact in a Confirmed state. This is because the PUT action always updates a field, even if the input is the same as the previous value, and the email address of a Confirmed contact can only be changed with an action by that contact. If you're working on an implementation that handles groups of contacts, I would definitely advise making use of our bulk APIs, as they do not have this same limitation as a result of being unable to change email addresses.

You can find information about our bulk APIs here: http://developer.constantcontact.com/docs/bulk_activities_api/bulk-activities-import-contacts.html

Sincerely,