Hi

When inheriting from the "res.partner" model using delegation inheritance, you might face some challenges in customizing the view form to include your new fields and related action buttons. Here are a few suggestions to help you overcome this issue:

* Ensure that the field names you added in the "bostana.vendor" model match the field names used in the view form definition. The field names should be consistent for the inheritance to work correctly.
*  In the view definition of the form, make sure to include your new fields explicitly. You can do this by extending the existing form view or creating a new form view that inherits from the original "res.partner" form view and adds your fields accordingly.
* Ensure that the user or user group has the necessary access rights to view and modify the new fields. Verify the access rules and security settings for the "bostana.vendor" model and its related fields.

Hope it helps

Hi 

Try this code

_inherits = {'res.partner': 'partner_id'}
_inherit = ['mail. thread', 'mail.activity.mixin']

partner_id = fields.Many2one('res.partner', string='Partner',)

Regards