To make it work did as you suggested.  1) Try to get  the contact using email address.  If no match, add new contact.  If match, capture the current values I need, append them to the values passed in, then Put the data back to just append the new list data as needed to the contact instead of changing the lists. ... View more

I am having similar issues.  I need my application to be able to  get access and make changes to contacts etc. using php cURL requests-  No "user" etc.  Here is something I saw on the internet about OAuth2 that seems like the answer?  Does CC support this?  ============ Application access In some cases, applications may need an access token to act on behalf of themselves rather than a user. For example, the service may provide a way for the application to update their own information such as their website URL or icon, or they may wish to get statistics about the users of the app. In this case, applications need a way to get an access token for their own account, outside the context of any specific user. OAuth provides the client_credentials grant type for this purpose. To use the client credentials grant type, make a POST request like the following: POST https://api.authorization-server.com/token grant_type=client_credentials& client_id=CLIENT_ID& client_secret=CLIENT_SECRET The response will include an access token in the same format as the other grant types.   Thanks for any help. ... View more

Thanks for this answer and the supporting details!  It's very detailed and looks like this is just not going to be too easy if I have 15 or 20 salespeople who change from time to time.  One thought I have is that I manage the salespeople in my HR/CRM system which is integrated with the CC API.  Each contact has its assigned salesperson's name/cel/email/url etc as a custom field.  Whenever I re-assign contacts in my HR/CRM System, it does a call to the API to update the custom fields for each re-assigned contact from old to new salesperson's info.   One challenge I see is that CC fields can only be one line text or date fields.  So I can't swap the salespersons headshot in custom fields.  Hmmm? ... View more