How to migrate your V2 integration to V3 with minimal user impact.
Constant Contact partners and developers who have an existing V2 API integration will need to migrate existing user data to the V3 API formats when building new V3 integrations.

Who Needs to Migrate Data

As a developer of a Constant Contact integration, you will need to update V2 data with V3 info if:

  • You have an existing integration with our V2 API
  • Your integration stores Constant Contact data locally (contacts, lists, campaigns, reporting and tracking, etc.)
  • You are building a new version of the integration using the V3 API
  • You want a seamless transition for existing users to the new version of your app.

Why Do I Need Update My V2 Data

The V3 API uses UUID formatted unique identifiers for resources, while the V2 API uses sequence identifiers. Adding the V3 ID existing user data, as needed, will allow the data to be recognized when making calls to the V3 API. Users will be able to use their existing account data with the V3 version of your application with minimal, if any, disruption or action on their part.

How Do I Update V2 Data with V3 IDs

There endpoints in the V2 and V3 APIs that return the V3 and V2 IDs. Here’s a list endpoints and the resource that they cross-reference, with links to instructions on how to use them.

Some tools have limits on how many times it can be used per user account; these limits are noted here and in the linked endpoint documentation.
Resource API Version Endpoint Description More Information
Contact V3 /contacts/contact_id_xrefs Use the contact_sequence_numbers query parameter to send in V2 contact id values, and get the V2 and V3 IDs in the response. More information
V2 Contact Collection Use the
include_contact_id=true
query parameter to have the V3
contact_id
for each contact included in the response payload.
More information
List V3 /contact_lists/list_id_xrefs Use the
list_sequence_numbers
query parameter to send in V2 list id values, and get the V2 and V3 IDs in the response.
More information
V2 List Collection Use the
include_list_id=true
query parameter to have the V3
list_id
property for each list included in the response payload.
More information