Which of the below matches the most to Library Module Pattern - Extension Pattern.

... is a pattern with two modules, a connector module that can be used to encapsulate an external API with the input/output structures and a wrapper module to expose the normalized API to the consumers.

Same as ECS with local replica but API module is provided. So any changes to the external system can notify OS, which OS then gets update from the ERP system (subscription system)

... tries to fetch data from local cache entity, if not there, get single entry from the external system. Cache only that record (read-through caching) Use when whole database too big or costly to synchronize. Integration only touches a small portion of the database. Avoid if access to lists of data is needed up front

... is needed if data is coming from MULTIPLE external systems. IS will decide which driver to use depending on the data.

... caches only summary data that is frequently lister, joined or searched. Full detail for a ) single entry is fetched directly from external system. Use when whole database too big or costly to synchronize. Details are only required for single entities (not lists)

Entity is exposed as read-only and API is available to centralize business logic for entity creation/update

Same as ECS with local replica but synchronization logic is separated. Pro: Code independence. Consumers of CS is not affected by Sync. Sync can orchestrate several CS