- The type of input/output a method should handle.
- Whether it acts on single or multiple records.
- Whether it’s a model-level method, computed field, etc.
📌 Realistic Odoo Examples
@api.model
def get_default_currency(self):
    return self.env.user.company_id.currency_id​
- Allowed looping over multiple records using self.
- No longer required — modern Odoo methods support multiple records by default.
3. @api.depends(*fields)Â
- Declares field dependencies for computed fields.
- Ensures the compute method re-runs when the listed fields change.
@api.depends(‘price_unit’, ‘quantity’)
def _compute_total(self):
for line in self:
line.total = line.price_unit * line.quantity
4. @api.constrains(*fields)Â
- Ensures validation logic when any of the fields listed change.
@api.constrains(‘discount’)
def _check_discount(self):
if self.discount > 100:
raise ValidationError(“Discount cannot exceed 100%.”)
5. @api.onchange(*fields)
- Reacts to changes in the given fields, mainly in the UI/form views.
- Does not save any values to the database unless explicitly returned.
📌 Purpose:
- In overridden create() methods when batch creation is required.
- Improves performance over looping in @api.model.
 Example
from odoo import api, models
class CustomTag(models.Model):
    _name = ‘custom.tag’
    name = fields.Char()
  Â
 @api.model_create_multi
    def create(self, vals_list):
        # vals_list: list of dictionaries
        for vals in vals_list:
            if ‘name’ not in vals:
                raise ValidationError(“Name is required for each tag.”)
        return super().create(vals_list)
- ✅ vals_list is a list of dictionaries, one for each record to be created.
- ✅ Suitable when using XML-RPC or Odoo batch APIs.
✅ Summary Table
Decorator |
Purpose |
| @api.model | Model-level logic, no specific record needed |
| @api.depends(…) | Recomputes field when dependencies change |
| @api.constrains(…) | Validates field constraints |
| @api.onchange(…) | UI-triggered updates (not saved to DB) |
| @api.model_create_multi | Efficiently handles bulk record creation |
