How to Create Mixins in Odoo 18 (Beginner-Friendly Guide)

Have you ever found yourself repeating the same blocks of code across different Odoo models? Maybe a behavior that needs to be reused in multiple apps? If yes, you’re already facing the exact problem mixins solve. Mixins help you write cleaner, reusable, and maintainable code — especially in Odoo 18, where modular development is more important than ever.

In this guide, you’ll learn exactly how mixins work, why they matter, and how to create your own mixins in Odoo 18 using simple, easy-to-follow steps.

 

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What Are Mixins in Odoo?

In Odoo, a mixin is a reusable class that provides specific features or behaviors that you can add to multiple models. You don’t need to rewrite the same function several times — you simply inherit the mixin.

Common examples of built-in mixins:

• mail.thread – adds chatter functionality
   
• mail.activity.mixin – allows scheduling activities
   
• portal.mixin – adds portal-related features
   
• sequence.mixin – enables automatic sequence generation

Mixins save time, reduce bugs, and help keep your modules consistent.

 

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Why Mixins Are Important in Odoo 18

Odoo 18 introduces performance improvements and a streamlined modular structure. Mixins play an even bigger role because:

• They help you avoid duplicated code
• They make models easier to maintain
• They encourage clean architecture
• They allow you to add a feature once and reuse it anywhere

If you want to write professional-quality Odoo modules, understanding mixins is essential.

 

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How to Create Mixins in Odoo 18 (Step-by-Step)

This is the core section — and the primary keyword appears naturally here.

Creating mixins in Odoo 18 is simple once you understand the basic structure. Below is a beginner-friendly walkthrough.

 

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Step 1: Define Your Mixin Class

A mixin class is usually placed in a separate Python file inside your module, such as mixins/custom_mixin.py.

Example:

Key points:

• Use models.AbstractModel for mixins
   
• _name should be unique
   
• Do not define database-specific behaviors unless needed
   
• Add reusable methods or fields

 

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Step 2: Inherit the Mixin When Needed

Now, you use your mixin inside any model where you want to reuse the features.

Example:

 

That’s it! Your project.task model now has:

• A new field extra_note
   
• Access to set_note_with_timestamp()
   
• Any other reusable logic you add later

 

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Step 3: Use the Mixin Logic

You can now call your mixin’s methods inside other model logic.

This keeps your code clean, organized, and easy to extend.

 

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Best Practices When Creating Mixins in Odoo 18

1. Keep Mixins Focused

Each mixin should have a single purpose:

• Logging
• Timestamping
• Notifications
• Computed value utilities
• Access rights helpers

This avoids confusion and makes your code predictable.

2. Avoid Heavy Business Logic

Mixins should not contain:

• Complex workflows
• Large compute chains
• Business rules specific to a single model

Keep them generic and reusable.

3. Use Clear, Consistent Names

Good naming patterns:

• custom.timestamp.mixin
   
• product.validation.mixin
   
• email.helper.mixin

Avoid vague names like common.mixin.

4. Always Document Your Mixins

Add docstrings explaining:

• What the mixin does
• Which models should use it
• Any dependencies

 

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Example: Creating a Practical Validation Mixin

Here’s a more advanced but easy-to-understand example.

Goal:

Add reusable validation to ensure a name field is never left blank.

Mixin Code:

 

Using the mixin:
 

This gives you a reusable validation rule across multiple models.

 

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Conclusion

Mixins are one of the most powerful tools available to Odoo 18 developers. They help you avoid repetitive work, keep your modules clean, and make your code easier to maintain. Once you understand the basics, you can build your own mixins for validation, logging, formatting, or any reusable functionality.

Have you tried creating your first mixin in Odoo 18 yet?
Share your experience or questions in the comments.

 

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Frequently Asked Questions (FAQs) 

1. What is a mixin in Odoo?

A mixin is a reusable abstract model that adds specific behavior or features to other models. It helps reduce code duplication and promotes clean module design.

2. How do I create a mixin in Odoo 18?

Create a class that inherits from models.AbstractModel, add reusable fields or methods, then include it in other models using _inherit.

3. Where should I place mixins in my Odoo module?

Most developers create a separate folder such as mixins/ or place them under models/ in a file like custom_mixin.py.

4. Can mixins have fields in Odoo?

Yes. Mixins can have fields, methods, and computed functions — as long as they stay reusable and generic.

5. Are mixins the same as multiple inheritance?

Mixins use Odoo’s multiple inheritance system, but they’re structured specifically for adding reusable behavior across different models.