Building Omnistudio Callable Apex

building-omnistudio-callable-apex: Callable Apex for Salesforce Industries Common Core

Specialist for Salesforce Industries Common Core callable Apex implementations. Produce secure, deterministic, and configurable Apex that cleanly integrates with OmniStudio and Industries extension points.

Scope

• In scope: Creating System.Callable classes for Industries extension points; reviewing callable implementations for correctness and risks; migrating VlocityOpenInterface / VlocityOpenInterface2 to System.Callable; 120-point scoring and validation
• Out of scope: Generic Apex classes without callable interface (use generating-apex); building Integration Procedures (use building-omnistudio-integration-procedure); authoring OmniScripts (use building-omnistudio-omniscript); deploying Apex classes (use deploying-metadata)

Core Responsibilities

1. Callable Generation: Build System.Callable classes with safe action dispatch
2. Callable Review: Audit existing callable implementations for correctness and risks
3. Validation & Scoring: Evaluate against the 120-point rubric
4. Industries Fit: Ensure compatibility with OmniStudio/Industries extension points

Workflow (4-Phase Pattern)

Phase 1: Requirements Gathering

Ask for:

• Entry point (OmniScript, Integration Procedure, DataRaptor, or other Industries hook)
• Action names (strings passed into call)
• Input/output contract (required keys, types, and response shape)
• Data access needs (objects/fields, CRUD/FLS (Create/Read/Update/Delete and Field-Level Security) rules)
• Side effects (DML, callouts, async requirements)

Then:

1. Scan for existing callable classes: Glob: **/*Callable*.cls
2. Identify shared utilities or base classes used for Industries extensions
3. Create a task list

Phase 2: Design & Contract Definition

Define the callable contract:

• Action list (explicit, versioned strings)
• Input schema (required keys + types)
• Output schema (consistent response envelope)

Recommended response envelope:

{
  "success": true|false,
  "data": {...},
  "errors": [ { "code": "...", "message": "..." } ]
}

Action dispatch rules:

• Use switch on action
• Default case throws a typed exception
• No dynamic method invocation or reflection

VlocityOpenInterface / VlocityOpenInterface2 contract mapping:

When designing for legacy Open Interface extensions (or dual Callable + Open Interface support), map the signature:

invokeMethod(String methodName, Map<String, Object> inputMap, Map<String, Object> outputMap, Map<String, Object> options)

Design rules for Open Interface contracts:

• Treat inputMap and options as the combined input schema
• Define what keys must be written to outputMap per action (success and error cases)
• Preserve methodName strings so they align with Callable action strings
• Document whether options is required, optional, or unused for each action

Phase 3: Implementation Pattern

Vanilla System.Callable (flat args, no Open Interface coupling):

Read `assets/pattern_callable_vanilla.cls` before generating — use when callers pass flat args and no VlocityOpenInterface integration is required.

Callable skeleton (same inputs as VlocityOpenInterface):

Read `assets/pattern_callable_openinterface.cls` before generating — use inputMap and options keys in args when integrating with Open Interface or when callers pass that structure.

Input format: Callers pass args as { 'inputMap' => Map<String, Object>, 'options' => Map<String, Object> }. For backward compatibility with flat callers, if args lacks 'inputMap', treat args itself as inputMap and use an empty map for options.

Implementation rules:

1. Keep call() thin; delegate to private methods or service classes
2. Validate and coerce input types early (null-safe)
3. Enforce CRUD/FLS (Create/Read/Update/Delete and Field-Level Security) and sharing (with sharing, Security.stripInaccessible())
4. Bulkify when args include record collections
5. Use WITH USER_MODE for SOQL when appropriate
6. Namespace handling: System.Callable is a standard interface (no namespace prefix required); omnistudio.VlocityOpenInterface2 uses the managed omnistudio package namespace — always qualify it. If the callable class will be deployed into a namespaced managed package, ask the user for the namespace prefix and apply it to custom class names (e.g., myns__Industries_XxxCallable)

VlocityOpenInterface / VlocityOpenInterface2 implementation:

When implementing omnistudio.VlocityOpenInterface or omnistudio.VlocityOpenInterface2, use the signature:

global Boolean invokeMethod(String methodName, Map<String, Object> inputMap,
                           Map<String, Object> outputMap, Map<String, Object> options)

Read `assets/pattern_openinterface.cls` before generating — complete VlocityOpenInterface2 skeleton with switch on dispatch and outputMap contract.

Open Interface implementation rules:

• Write results into outputMap via putAll() or individual put() calls; do not return the envelope from invokeMethod
• Return true for success, false for unsupported or failed actions
• Use the same internal private methods as the Callable (same inputMap and options parameters); only the entry point differs
• Populate outputMap with the same envelope shape (success, data, errors) for consistency

Both Callable and Open Interface accept the same inputs (inputMap, options) and delegate to identical private method signatures for shared logic.

Phase 4: Testing & Validation

Minimum tests:

• Positive: Supported action executes successfully
• Negative: Unsupported action throws expected exception
• Contract: Missing/invalid inputs return error envelope
• Bulk: Handles list inputs without hitting limits

Read `assets/pattern_test_class.cls` — complete test class skeleton (positive, negative, contract, bulk, and null-args cases) before generating tests.

Migration: VlocityOpenInterface to System.Callable

When modernizing Industries extensions, move VlocityOpenInterface or VlocityOpenInterface2 implementations to System.Callable and keep the action contract stable.

Guidance:

• Preserve action names (methodName) as action strings in call()
• Pass inputMap and options as keys in args: { 'inputMap' => inputMap, 'options' => options }
• Return a consistent response envelope instead of mutating outMap
• Keep call() thin; delegate to the same internal methods with (inputMap, options) signature
• Add tests for each action and unsupported action

Read `assets/pattern_migration.cls` — annotated before/after migration example (VlocityOpenInterface2 → System.Callable) before starting migration work.

Best Practices (120-Point Scoring)