REST API call from url

Hi, I want to fetch the json-ld of an item from within openrefine in order to get the omeka-id of an item and form a link to it from an external resource using, for instance, the title.
I used this naive url
http://omeka.mysite.com/api/items?search=”+ value
This way, however, i get a json with all items which contain the value of the cell .
How do I narrow, for instance, for a specific item set?
Thanks
Yael

If you know the id, just use http://omeka.mysite.com/api/items/xxx or /api/items?id=xxx.