With a header a Content-Type header:
And the BODY as (from the example - all on one line):
Am I totally off base? Missed a tiny little thing?
It looks like you're attempting to use the OAuth method for authentication. You're one of the first customers to get this up and running and it would be useful to find out a couple of things to help you.
1. What language are you coding this in?
2. What OAuth library or open source project did you use for the OAuth implementation?
3. Are you receiving an error code when you POST this activity (401, 409, 415, other)?
Dave Berard Senior Product Manager, Constant Contact
Due to a security vulnerability acknowledged by the OAuth community, Constant Contact is retracting support for OAuth Authentication. API adopters should adopt Basic Authentication over HTTPs.
You can read more on the Basic Authentication model here.
We acknowledge and apologize for the impact this could have on developers currently building applications. We believe this action is in the best interests of our Constant Contact account holders and in the best interest of our API adopters (It appears likely that the security vulnerability will require coding changes on the part of both Constant Contact and any OAuth adopters. Since our OAuth implementation is quite new, few OAuth based implementations have been deployed - and hence it is our hope and belief that changing models now is the most expedient - and secure - approach).
If you are interested in more information on the nature of the OAuth security vulnerability, please see the OAuth security advisory, here.
Tom M Group Product Manager – Content Editing Constant Contact