@Axel Mendoza Thank you for helping me

I noticed that Odoo 13 has a feature that gives you the ability to create models & fields from the UI, my Idea is to build a feature like this one, but with bespoke field type, for example, a new field type "Title" which the user can type max of 50 characters or other customized constraints, so when I create a field with this type it should generate a new constraint to validate it, I already mapped the model and the basic fields with Odoo, in this stage I need to know how Odoo stores the constraints so I can do the same.

note: I can't do Python constraint because the model is created from the UI so I don't have a Python class or a code file

Any Ideas are welcome!

It's not very clear for me what you wanna do with your transition layer to create my customized types in the Odoo world.​

But there are 2 types of constraints in Odoo.

1.  SQL constraints: https://www.odoo.com/documentation/16.0/developer/tutorials/getting_started/11_constraints.html#sql
2. Python constraints: https://www.odoo.com/documentation/16.0/developer/tutorials/getting_started/11_constraints.html#python

If you dynamically generate your custom models constraints into an Odoo module like if you have manually create it and Install it you could get whatever you want to do integrated completely with Odoo. 

If you are looking for a way to save the python constraints as data in order to execute it, I think you will need to also create that by yourself