What’s New

The Constant Contact V3 API is a complete rebuild of our API in every sense. It has improved performance and reliability, and contact functionality is the same as users experience using Constant Contact. The V3 API is a REST-ful API that uses JavaScript Object Notation (JSON) payloads for all endpoints and methods except for one multipart-form endpoint.

Mobile Friendly Payload Options

We’ve updated our API to be more mobile-friendly, allowing integrations to choose which fields they’re interested in beyond the basics in order to optimize the amount of data sent. Major components of the Contact data object are now treated as subresources. Subresources are not included by default in contact object response payloads. This gives developers more control over the size and complexity of payloads sent back and forth on API calls. Testing has shown a 40% decrease in size of contacts payloads when subresources are not included.

Learn more here.

Improved Security

Security improvements implemented in the V3 API protect users, partners and contacts from having their accounts and data compromised in the following ways:

  • Using the most current OAuth 2.0 methods, including:
  • Scopes
    Users can know which data and functionality an application is requesting access to
    Developers can be selective in what their apps are asking access to
  • Short-lived access_tokens along with refresh tokens for apps using OAuth2 server flow.
  • Eliminating basic authentication: removes the risk of compromised credentials Integrations no longer have to ask users for their updated credentials
  • More secure database handling

Learn more, including step-by-step instructions to implement OAuth 2.0 server and client authorization flows in your app.

Simplified Custom Fields

Constant Contact users can create renamed custom fields via the API so that they can collect contact information that is specific to their needs, and see custom fields with the name they gave them. Additional custom field functionality includes a greater number of custom fields - up to 100 per account, and a separate set of endpoints to manage custom fields.

Learn more.

Birthday & Anniversary Support

The V3 API now supports the birthday and anniversary properties in the contact object. This means integration users can take advantage of autoresponder messages to send birthday and anniversary email campaigns.

Learn more.

REST Standards

The underlying services were redesigned to comply with our REST API standards created at the beginning of the V3 API project. This allows us to provide:

  • A consistent developer experience across all services and endpoints
  • Parity between API and in-product experiences
  • Swift deployment of new features to the API

Bulk Activities

In response to feedback received in our forum, support cases, and conversations with developers, we’ve made improvements to Bulk Activity functionality. V3 API Bulk Activity functionality has improved performance and increased functionality.

Learn more about bulk activity functionality.

Move to the Cloud

We’ve deployed the V3 API in the cloud for enhanced stability, performance and scalability.