API Filtering

As far as i can tell, even in the examples, these filters aren't looking for a single property with the name and value. it's looking a device having a property with name sn.sys_class_name and also having a property with value cmdb_ci_hardware. However, i don't think there's anything in the filter logic that actually pairs the two up, looking only for a property with name sn.sys_class_name also having the value cmdb_ci_hardware. Also, looks like the criteria also has to be in quotes. Not sure if this is exactly how it works under the hood, but this is how I understand it: the api looks at the JSON and evaluates it against the filter. There's an object in the JSON for each returned device called "customProperties". That object is a list, so it contains objects, each of which has a name and a value. It would appear that if you specify a dot in the field name (i.e. customProperties.name) the filter uses an "in" operator to see if your criteria (sn.sys_class_name) is in the list somewhere. In this case, it's looking to see if there's a property with name = "sn.sys_class_name" anywhere in the customProperties object. It would appear to repeat this process for the value. 

That said, I personally don't do much filtering in my API call beyond a single criterion. My API calls are already being called from a script which gives me the opportunity to do post request-response processing, so I tend to pull down more than I usually need and do further filtering in the script. Not making excuses, just offering how I work around the issue.