Extension Attributes Magento 2: Key Characteristics and Use Cases

Extension Attributes Magento 2: Key Characteristics and Use Cases

Want to enhance the functionalities of your Magento 2 core entities? Extension attributes Magento 2 extends the functionality without modifying core code.

In this tutorial, we will explore the key characteristics, use cases, and steps to configure extension attributes.

Key Takeaways

  • Learn what extension attributes are in Magento 2 and how they enhance core entities.

  • Discover the key characteristics of extension attributes, including API support.

  • Explore various use cases for extension attributes, such as third-party integrations.

  • Learn the difference between custom and extension attributes.

  • Get step-by-step instructions to add extension attributes in Magento 2.

What are Extension Attributes?

What are Extension Attributes

Extension attributes in Magento 2 are a type of custom attribute. These are used to extend the functionality of core entities in both Adobe Commerce and Magento Open Source.

These include:

  • Products

  • Customers

  • Orders

There is no need to modify the core code directly. The feature called extension attributes are added through code and configuration. They are used to add additional properties or functionalities to these entities.

These are particularly useful for developers when customizing or integrating with third-party systems. Extension attributes provide a more flexible and decoupled way to extend functionality. They ensure flexibility and scalability for your eCommerce PHP extensions.

Key Characteristics of Extension Attributes

1. Defined in XML

  • Extension attributes are specified in extension_attributes files. These are part of the module's configuration files in Magento 2.

  • The XML configuration allows developers to declare new attributes that extend the core entities in a structured and organized manner.

  • The use of XML ensures that the extension attributes are easily readable and maintainable. It keeps the customizations separate from the core code.

2. Type-Safe

  • Extension attributes enforce strict data types. It helps maintain data integrity and consistency. They are linked to more complex data types than custom attributes.

  • Strict data types mean that the data type of each attribute is clearly defined and enforced throughout the system. It reduces the risk of data-related errors.

  • If an attribute is defined as a string, any attempt to set it to a non-string value will result in an error.

3. Decoupled from Database

  • Extension attributes do not require changes to the database schema. Instead, they are managed entirely through code and configuration files.

  • The approach makes them less intrusive and easier to handle. This is especially true during upgrades or when maintaining the system.

  • It also avoids potential conflicts or issues that can arise from direct database modifications.

4. Integration-Friendly


  • Extension attributes are ideal for integration with third-party systems.

  • They allow developers to add fields that might be required by external systems like:

  1. CRMs

  2. ERPs

  • It eliminates the need to modify the core Magento codebase.

  • The flexibility helps in powerful integrations that can evolve without disrupting the existing system.

5. API Support

  • Magento's API (both REST and SOAP) can work with extension attributes. It allows these custom fields to be included in API responses and requests.

  • The feature is particularly useful for developers who need to expose additional data via the API. They also consume additional data provided by external systems.

6. Custom Module Enhancement

  • When developing custom modules, extension attributes help add module-specific data fields to core entities.

  • It extends the functionality without modifying the core entity definitions. It makes the customizations more modular and easier to manage.

7. Ease of Maintenance

  • Extension attributes are defined through configuration files. They do not alter the core code or database schema. This makes it easier to maintain.

  • The separation of concerns helps ensure that customizations do not interfere with the core functionality. It makes upgrades and troubleshooting simpler.

8. Scalability

  • Extension attributes support the scalability of the Magento platform.

  • They enable the addition of new features and data fields without affecting the performance or stability of the core system.

  • The scalar system can be easily scaled to meet evolving business requirements.

Use Cases of Extension Attributes

1. Third-Party Integrations

Third-Party Integrations

  • Integrating Magento with third-party CRMs, ERPs, or logistics platforms.

Use Case:

  • Extension attributes can store and transfer additional data required by these systems to Magento entities like:
  1. Orders

  2. Customers

  3. Products

  • You should add a crm_customer_id or erp_order_status to the customer and order entities. It helps synchronize data between Magento and the external systems.

2. Custom Module Development

  • Developing a custom module that requires additional data fields on existing Magento entities.

Use Case:

  • Enhancing Magento’s product entity with additional attributes such as manufacturer_warranty or product_origin. It helps support module-specific functionality.

  • It helps in creating more feature-rich and customized solutions without altering the core code.

3. API Enhancements

  • Extending the Magento API to include additional data fields.

Use Case:

  • Exposing new attributes through the REST or SOAP APIs. These are not part of the standard Magento data model.

  • It is useful for applications that need to access or update additional data via API request.

4. Custom Reporting

  • Adding custom fields for advanced reporting purposes.

Use Case:

  • Storing additional information such as sales_channel or promotional_code on orders. It helps generate more detailed and customized reports.

  • These fields can help in segmenting data and analyzing trends more effectively.

5. User Personalization

  • Enhancing the customer experience by personalizing their interactions based on additional attributes.

Use Case:

  • Adding fields like preferred_language or shopping_preferences to the customer entity. It helps tailor the shopping experience.

  • The data can be used to customize content, marketing messages, and product recommendations.

6. Workflow Automation

  • Automating business processes by adding custom workflow attributes.

Use Case:

  • Adding fields such as order_processing_stage or approval_status to manage and automate order processing workflows.

  • These attributes can be used to trigger specific actions or notifications based on the status of an order.

Difference Between Custom and Extension Attributes

Feature Custom Attribute Data Extension Attributes
Definition These are additional fields added to standard Magento entities to store extra information. These are the attributes that extend the functionality of core Magento entities for complex customizations.
Configurability These can be created and managed through the Magento Admin or programmatically. They must be defined programmatically through custom modules and XML files.
Use Cases They add a "Manufacturer" field to products, including "Membership Level" for customers and storing "Delivery Instructions" for orders. They associate "Supplier" entities with products, linking "Loyalty Points" to customers and attaching "Custom Shipping Information" to orders.
Implementation These can be implemented via Admin UI, setup scripts, or custom modules. These can be implemented via custom modules involving changes in XML configuration and PHP code.
Storage They are stored in Magento's EAV (Entity-Attribute-Value) tables. They are managed separately. They typically require custom database tables or structures.
Entity-Specific These are directly associated with standard Magento entities. These include products, categories, customers, and orders. These can be linked or related to multiple entities. They often involve complex relationships.
Ease of Use These are user-friendly. They can be added and configured without needing deep technical knowledge. They require developer knowledge for setup and maintenance.
Performance Impact They have minimal impact. They are part of the EAV structure that Magento optimizes for performance. They can have a more significant impact if not managed properly. They often require custom database handling.

How to Add Extension Attributes Magento 2

Step 1: Create the extension_attributes.xml file

Declare your extension attributes in one XML file by running the following command:

<!-- etc/extension_attributes.xml --> <?xml version="1.0"?> <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Api/etc/extension_attributes.xsd"> <extension_attributes for="Magento\Sales\Api\Data\OrderInterface"> <attribute code="tigren_attribute" type="Tigren\Example\Api\Data\TigrenAttributeInterface" /> </extension_attributes> </config>

Step 2: Create an interface for your extension attribute

<?php namespace Tigren\Example\Api\Data; interface TigrenAttributeInterface { const VALUE = 'value'; /** * Return value. * * @return string|null */ public function getValue(); /** * Set value. * * @param string|null $value * @return $this */ public function setValue($value); }

Step 3: Create a concrete class for the interface that you created

<?php namespace Tigren\Example\Model; class TigrenAttribute implements \Tigren\Example\Api\Data\FoomanAttributeInterface { /** * {@inheritdoc} */ public function getValue() { return $this->getData(self::VALUE); } /** * {@inheritdoc} */ public function setValue($value) { return $this->setData(self::VALUE, $value); } }

Step 4: Create a plugin to save and retrieve the new attributes

<!-- etc/di.xml --> <?xml version="1.0"?> <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd"> <type name="Magento\Sales\Api\OrderRepositoryInterface"> <plugin name="save_tigren_attribute" type="Tigren\Example\Plugin\OrderSave"/> <plugin name="get_tigren_attribute" type="Tigren\Example\Plugin\OrderGet"/> </type> </config>

Step 5: Save the order

<?php namespace Tigren\Example\Plugin; use Magento\Framework\Exception\CouldNotSaveException; class OrderSave { ... public function afterSave( \Magento\Sales\Api\OrderRepositoryInterface $subject, \Magento\Sales\Api\Data\OrderInterface $resultOrder ) { $resultOrder = $this->saveTigrenAttribute($resultOrder); return $resultOrder; } private function saveTigrenAttribute(\Magento\Sales\Api\Data\OrderInterface $order) { $extensionAttributes = $order->getExtensionAttributes(); if ( null !== $extensionAttributes && null !== $extensionAttributes->getTigrenAttribute() ) { $tigrenAttributeValue = $extensionAttributes->getTigrenAttribute()->getValue(); try { // The actual implementation of the repository is omitted // but it is where you would save to the database (or any other persistent storage) $this->tigrenExampleRepository->save($order->getEntityId(), $tigrenAttributeValue); } catch (\Exception $e) { throw new CouldNotSaveException( __('Could not add attribute to order: "%1"', $e->getMessage()), $e ); } } return $order; } }


1. What is the process of implementation to fetch Extension Attributes data?

You can fetch extension attribute data by injecting the repository class. It can be done using getById to retrieve the entity, and calling the extension attribute's getter method. It ensures proper implementation to fetch extension attribute data.

2. How the implementation of Extension Attributes are used in Magento 2?

Implementation of extension attributes is used to add custom fields without altering the database schema. The process involves defining attributes, updating interfaces, and using getter and setter methods. These enhance commerce PHP extensions.

3. What should I do if Extension Attributes do not appear in Magento 2?

If extension attributes do not appear in Magento 2. You should ensure they are correctly defined in the extension_attributes.xml file and that the data interface is updated. Clear cache and reindex to reflect the changes in your commerce PHP extensions.

4. When do I need to create Extension Attributes in Magento 2?

You need to create extension attributes in Magento 2 when additional custom data is required for existing entities without modifying the core code. It allows for enhanced flexibility and scalability in your eCommerce PHP extensions.



Extension attributes in Magento 2 ease the development process by enhancing the core entities of your Magento 2 store. The tutorial outlines several key characteristics, including:

  • Extension attributes specified through XML configuration files keep customizations organized.

  • They enforce strict data types to maintain data integrity and consistency throughout the system.

  • Ideal for integrating with third-party systems like CRMs and ERPs without modifying the core codebase.

  • Magento’s API supports extension attributes, allowing inclusion in API responses.

Want to enhance the complete functionality of your Magento 2 store with extension attributes? Choose managed Magento hosting.

Ruby Agarwal
Ruby Agarwal
Technical Writer

Ruby is an experienced technical writer sharing well-researched Magento hosting insights. She likes to combine unique technical and marketing knowledge in her content.

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