searchCriteria using custom attributes on product using string compare

[tony2k84]

V1/products?searchCriteria[filter_groups][0][filters][0][field]=test1&searchCriteria[filter_groups][0][filters][0][value]=30&searchCriteria[filter_groups][0][filters][0][condition_type]=gt

I am using above searchCriteria string but the output seems to compare the attribute test as in a string. it is returning 5>50. Is there a condition or configuration to fix this? Plese help

[tony2k84]

Not sure if custom attributes other operations are enabled apart from "eq"