To translate and isolate differing domain models is correct. An anti corruption layer sits between service domains to translate concepts and data from one domain into the internal domain and to isolate your core model from the design and terminology used by other domains.

The anti corruption layer implements adapters and translators that map external contracts and structures into the internal domain model and it enforces boundaries so that changes in one domain do not leak into another. This preserves the integrity of your bounded context and keeps domain logic clean and consistent across microservices.

Apigee is incorrect. Apigee is an API management product that provides gateways, routing, analytics and policy enforcement and it is not the conceptual pattern for translating and isolating differing domain models.

To block SQL injection attacks is incorrect. Preventing SQL injection is a security responsibility handled by input sanitization, parameterized queries and web application firewalls and it is not the primary purpose of an anti corruption layer.

To validate that incoming data matches a schema is incorrect. Schema validation is a contract or data quality concern and it can be a part of an anti corruption layer but it does not capture the primary role which is semantic mapping and isolation between differing domain models.

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