The current docs do not give an example of serialization support for JSON.

I attempted to use Marshmallow's dumps feature

db.MyModel.Schema.dumps(someInstanceOfMyModel)
# throws this error:
TypeError: dumps() missing 1 required positional argument: 'obj' marshmallow

But received an error. I am currently using someInstanceOfMyModel._raw to get the data for JSON output.

Feature Request
Add a expose a dumps method to get a dict.

db.MyModel.dumps(someInstanceOfMyModel)