An Integration Service (IS) module, within the OutSystems Architecture Canvas, serves as a dedicated technical wrapper. Its primary function is to connect to a single external system, such as a REST API, SOAP web service, or an external database. This module isolates the rest of the application from the technical complexities of the integration, handling aspects like authentication, data format conversion, and error handling. It exposes a normalized, stable API for the core business logic to consume, thus promoting loose coupling and simplifying maintenance when the external system changes.

A. This is too generic. While an IS module is a type of library, its purpose is specifically for external system integration, not general-purpose reusable code, which is typically placed in a Lib module.

B. This describes a Core Service (CS) module implementing an abstraction or facade pattern over multiple, similar IS modules, not the purpose of a single IS module itself.

C. This describes a UI module, often a Library (Lib) containing UI Patterns or a Block module, which belongs in the Foundation or End-User layer, not the Integration layer.

D. This explicitly describes a Theme module, which is responsible for the application's look and feel and resides in the End-User layer.

1. OutSystems Official Documentation

"Designing the architecture of your OutSystems applications":

Section: "The Integration Layer": This section defines the layer's purpose: "This layer contains all the modules that are used to integrate with the outside world. For example

with external systems or other OutSystems applications."

Section: "Module types in the Integration Layer": It specifies that an Integration Service (IS) module "wraps a single external service (e.g. a single SOAP API

a set of related REST APIs

a single external database)." This directly supports the role of a technical wrapper for consuming an external service.

Section: "Module types in the Core Layer": It describes Core Service (CS) modules

which can "define a new conceptual API that abstracts from several IS modules

" confirming that option B describes a CS

not an IS module.

2. OutSystems Official Documentation

"Application Architecture":

Section: "Integration Layer": "The Integration Layer isolates the core of the application from external systems... It contains all the implementation details needed to connect

and fetch or update data from external sources." This reinforces the concept of an IS module as a wrapper for normalization and isolation.