Magento 2 Dependency Injection

Before writing code

Fetch live docs:

1. Web-search site:developer.adobe.com commerce php development components dependency-injection for the DI guide
2. Fetch https://developer.adobe.com/commerce/php/development/ and navigate to DI documentation
3. Web-search site:developer.adobe.com commerce php development build di-xml for di.xml reference

Conceptual Architecture

How DI Works in Magento

Magento's Object Manager reads di.xml configurations and automatically injects dependencies into class constructors. You declare what you need; the framework provides it.

Constructor injection is the primary pattern — declare dependencies as constructor parameters with type hints.

di.xml Scope