Cloud Kicks has a multi-screen flow that its call center agents use when handling inbound service desk calls. At one of the steps in the flow, the…

Invocable methods are the standard way to execute Apex code from within Flows. They can make HTTP callouts to external systems and return data back to the Flow. The @InvocableMethod annotation allows Apex methods to be called from Flows, Process Builder, and REST APIs. The method can perform the callout to the external order management system and return the order numbers and dates as a list that can be displayed in the flow screen.

A. Outbound messages are for sending data out of Salesforce asynchronously, not retrieving data for display in flows.

B. Apex REST classes expose Salesforce data to external systems, not for internal flow consumption.

C. Apex controllers are for Visualforce pages and Lightning components, not directly callable from flows.

3. References:

1. Salesforce Developer Guide - Invocable Methods: "Use the @InvocableMethod annotation to identify methods that can be run as invocable actions." (Developer Guide, Apex Developer Guide, Working with Data in Apex, Invocable Actions section)

2. Salesforce Flow Developer Guide - "Add an Apex Action to call an invocable method" (Flow Developer Guide, Build Flows, Add Elements to Your Flow section)

3. Salesforce Integration Patterns and Practices - "Request and Reply pattern for real-time integration" (Integration Patterns and Practices Guide, Pattern Summary section)

1. Salesforce Flow Builder Dev Guide, “Apex Actions” – “Annotate methods with @InvocableMethod to make them available in Flow”, 2024-02 release, p. 246.

2. Apex Developer Guide, “Making HTTP Callouts from Apex”, Winter ’24, p. 526.

3. Salesforce Help, “Add an Apex Action to Your Flow”, article ID 000338807, para. 2.