This does not look at all usable. Your application is exposed to the "internal binary format" that SQLite has chosen:

    select jsonb_extract('{"foo": {"bar": 42}}', '$.foo');

    ┌────────────────────────────────────────────────┐
    │ jsonb_extract('{"foo": {"bar": 42}}', '$.foo') │
    ├────────────────────────────────────────────────┤
    │ |7bar#42                                       │
    └────────────────────────────────────────────────┘