I don't think so -- I'm looking for a database that will actually enforce a JSON schema for you -- I don't think Postgres has any built-in support for JSON schematization.
I could always do validation before inserting data, but that opens me up to error on my side which I'd like to avoid=)
You are trying to hammer a screw in. If what you want is a facility for the database to provide you with JSON on query, Postgres has a couple of functions for that, namely array_to_json and row_to_json: https://www.postgresql.org/docs/9.2/static/functions-json.ht...
I could always do validation before inserting data, but that opens me up to error on my side which I'd like to avoid=)