Constant
Contact

Build Email Solutions That Connect with Small Businesses

Our API empowers developers to integrate powerful email marketing, contact management, and e-commerce features into their applications.

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Quick Start

Everything you need to make your first API call and send your first campaign.

Get your API Key

Sign up for a developer account and get your API key to start building.

OAuth2 Authentication

Learn how to securely authenticate your application using OAuth2.

Send Your First Campaign

Follow our guide to send your first email campaign programmatically.