Two ways to authenticate
The easy way
The easy way to authenticate is in clear text through the URL. Simply pass your username and password along with any other parameters that are required for the method, like this:
http://www.43things.com/service/authentication_test?api_key=1234&username=www&password=1234
The secure way
The more complicated way uses the same method of authentication that the Atom API uses: X-WSSE. More information on how to do that is here:
http://www.xml.com/pub/a/2003/12/17/dive.html
One thing to note is that since we don’t store your plain password, you’ll need to pass an encrypted version of your password, which you can retrieve from this page (assuming you’re logged in):