ParadeDB also supports writing query builder functions as JSON objects. This is useful for programmatic generation or client applications that construct search queries as structured JSON. To write a query as JSON, first call SELECT on the desired query builder function, which returns its JSON representation: 
SELECT pdb.regex('key.*');
Next, paste this JSON string into the right-hand side of the @@@ operator and cast it to pdb.query: 
SELECT description, rating, category
FROM mock_items
WHERE description @@@
'{
    "regex": {
        "pattern": "key.*"
    }
}'::pdb.query;
The JSON query object must be explicitly cast to pdb.query using ::pdb.query.