In case of doing simple API tests like locking the view or checking properties of objects with known dbId, etc, you can do that on any of the Autodesk storage websites like A360.
You just have to open the model you are interested in, open up the browser console, and there you can access the viewer stored under the NOP_VIEWER variable.
This way you have full access to the viewer, so you can check its properties, and run its functions as shown in the above image.
Follow @AdamTheNagy Adam Nagy joined Autodesk back in 2005 and has been providing programming support, consulting, training and evangelism to external developers. He started his career in Budapest, then worked in Prague for 3 years and now lives in South England, UK. At the moment focusing on Inventor and Fusion 360, plus cloud and mobile related technologies. Adam has a degree in Software Engineering and has...