The EditContact function is used to edit an existing contact.
When calling this function, the Function parameter sent to the API should be EditContact.
ContactId - This is the Id of the contact. If you added the contact via the API, you'll already have the Id. If you're using a contact that you entered from the CRM, this page explains how to find the Id. *Note: ContactId should be treated like a string, NOT an integer or any other number type.*
AssignedTo - (Optional) the UserId of who the contact is assigned to. Here are instructions for finding the correct UserId.
All other fields are the same as the CreateContact function. Note that for the most part, we will only edit the fields you pass us, so you must pass a blank value to clear a field out. The only exception is the ContactName field where if you pass any part of the contact name, we'll update the whole thing (so don't just pass us a middle name, pass the first and last names too) and the custom fields which are all treated as one field, so you must pass in the entire array each time.
This code shows how to edit an existing contact.