Search Zoho Inventory Items module via API

Search Zoho Inventory Items module via API

How can I search Zoho Inventory Items by custom fields, categories, etc using the API? This is not documented.

Is there an advanced search function like CRM's COQL search available via the Zoho API?

If there is an undocumented way to search Items via the API, could Zoho please post instructions and examples here in response to this question, or otherwise direct me to existing documentation.

Thanks.