I couldn't seem to find a straightforward answer to my questions in the FAQ or fourms, so I figured I'd ask.
We are looking into integrating our web application with Constant Contact. We want to allow users to link their Constant Contact account with their web app account. Our users would be able ot synchronize their contacts between both applications and our web app would run an email campaign through Constant Contact on their behalf.
Basically, I can't tell if the API allows users to link their Constant Contact accounts with third party apps. It seems like the API only works with the account that the key was generated for.
If this isn't possible, we want to be able to output an HTML and plain text email that they can send through Constant Contact. What is the best way to supply our customers with this?
You do generate an API Key under a specific account, and the key will always be associated with that account, but you can use that API Key for any number of Constant Contact accounts other than the one it was generated under.
Depending on which type of authentication you use, you either provide the username and password of the account you want to access, or the access token for the account you want to access, in addition to the API Key. You would want to store the login credentials or access token for every account that will be using your app. It would probably make the most sense for you to use OAuth 2 to generate an access token for each user, and then store the access tokens in a secure file or database. No need to have more than one API Key.