I'm wondering if a Developer/Sandbox Environment for Testing Integrations has been created yet, and if so, how do I access it? Based on my searching, there is not, however all information I can find is over 5 years old. Has anything changed?
As of the most recent response I could find, the official workaround is to create a trial account and use that for testing purposes. This works, however it eventually expires requiring me to either apply for a new trial account or request an extension of my free trial.
A Developer Environment for Testing Integrations is very important because without it, the only way to test is to point at a live environment, which has the potential to seriously mess up existing data. This environment should not be able to send emails which would mean a) it would not accidentally send emails due to an error encountered during testing and b) would not be of any value to your customers outside of testing.
Thank you for reaching out to Constant Contact's API Support.
We do not have a testing environment available to developers. You are welcome to email us at webservices(at)constantcontact(dot)com and we can discuss other options.