No instances on API response

I dont usually get my instances that way, so apologies if I'm about to be confusing. :) But I think you are using this call: "/device/devices/{deviceId}/devicedatasources/{hdsId}/instances". I dont think that hdsId is the global template datasource id. In your post you mention "device datasource ID" in your text but then make a reference to {datasourceid} and they arent the same.

If you already knew that, apologies. Anyway, what I usually do is slightly different. I do:

• pull "/device/devices/{deviceId}/devicedatasources" to get the "instantiation" of the global datasource id that exists at the device level.
• hunt through the responses to get the device-level template Id of the datasource by name.
• If found, grab the "dataSourceId" property, to get the device-level template Id of the datasource.
• pull /device/devices/{deviceId}/instances to get back all my instances, but I also filter on the device template datasource id with &filter=dataSourceId:"{the thing I just got}"
• and from there, I have my actual instances in the responses

So TL;DR I just wanted to be sure you know that for some of these calls, the "datasource id" isnt necessarily the number you'd see when editing the datasource. Apologies if I just focused in on the wrong thing in your post.

Maybe I'll just focus on something where I have some target devices in a Map and I'm snagging the actual instances of a specific logicmodule to roll up into something else I'm doing. Its a different way to get to the data, and I have some function calls here that I dont show but hopefully are clear.

If this muddies the water, I apologize. I'm just hoping it will help, since so many people here have helped me.

Feel free to ignore me and just open a support ticket. :)

for (String currentObject : filteredObjects.keySet()) {
    
    def Map<String, String> objectInfo = filteredObjects[currentObject];
    
    def String objectId = objectInfo."id";
    def String hostname = objectInfo."name";
    def String displayName = objectInfo."displayName".trim();
        
    //pull list of datasources that can be found on the resource
    def String deviceDatasourcesEndpoint = "/device/devices/" + objectId + "/devicedatasources";
    def String deviceDatasourcesFilter = "";
    
    deviceDatasources = getAPIObjectsByFilter (deviceDatasourcesEndpoint, deviceDatasourcesFilter, accessId, accessKey, account, httpclient);
    
    //one of these is the correct resource, grab it
    vmwareEsxiCpuDatasource = getDatasourceByName(deviceDatasources,"VMware ESXi CPU");
    
    if (vmwareEsxiCpuDatasource != null) {

        //get dataSourceId. This is not the global template ID, but the "instance" of the global one
        dsId = vmwareEsxiCpuDatasource["dataSourceId"];

        //call API for the instances belonging to this devices' "VMware ESXi CPU" datasource
        instancesEndpoint = "/device/devices/" + objectId + "/instances";
        instancesFilter = "&filter=dataSourceId%3A%22" + dsId + "%22"
                
        snagInstances = getAPIObjectsByFilter (instancesEndpoint, instancesFilter, accessId, accessKey, account, httpclient);
        
        //do the actual roll-up total for the resource folder (usually a cluster)
        snagInstances.each {
            
            def thisInstance = it; //Map
                    
            //update the group rollup
            def Integer instanceCoreCount = getMapFromProperties(thisInstance."autoProperties")["auto.cpu.core_count"].toInteger();
            esxiCoreCount += instanceCoreCount;
            
            def Integer instanceThreadCount = getMapFromProperties(thisInstance."autoProperties")["auto.cpu.thread_count"].toInteger();
            esxiThreadCount += instanceThreadCount;
                    
        }

    }

}