I'm new to the Valence API and Desire2Learn/Brightspace and I'm unable to make successful API calls. Currently I'm using the language bindings at the Valence Site, and can authenticate properly. However, I have made the "Get Versions" call to work sometimes, but I have not been able to make any other call, even while using the user credentials that are supplied. Any other call and I receive a 400 Bad Request header.
All of the fields are left as the defaults, including the host which is "valence.desire2learn.com". If anybody can help solve my issue I would immensely appreciate it.
EDIT: I discovered that my problems lie with the server that I was testing against. If I change the host parameter to the URL that the API test tool uses (devcop.brightspacedemo.com), I can make API calls again.
The host you mention is a public test, demo site. The fact that you can make a GET versions call (which only needs to be made anonymously), but no other call leads me to wonder if you have appropriate user credentials for that site?