Apex Class

Generate well-structured, production-ready Apex classes for Salesforce development.

Scope

Generates:

• Service classes (business logic layer)
• Selector / query classes (SOQL encapsulation)
• Domain classes (SObject-specific logic)
• Batch Apex classes (Database.Batchable)
• Queueable Apex classes (Queueable, optionally Finalizer)
• Schedulable Apex classes (Schedulable)
• DTO / wrapper / request-response classes
• Utility / helper classes
• Custom exception classes
• Interfaces and abstract classes

Does NOT generate:

• Triggers (use a trigger framework skill)
• Unit tests (use a test writer skill)
• Aura controllers
• LWC JavaScript controllers

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Gathering Requirements

Before generating code, gather these inputs from the user (ask if not provided):

1. Class type — Service, Selector, Batch, Queueable, Schedulable, Domain, DTO, Utility, Interface, Abstract, Exception
2. Class name — or enough context to derive a meaningful name
3. SObject(s) involved — if applicable
4. Business requirements — plain-language description of what the class should do
5. Optional preferences:
   • Sharing model (with sharing, without sharing, inherited sharing)
   • Access modifier (public or global)
   • API version (default: 62.0)
   • Whether to include ApexDoc comments (default: yes)

If the user provides a clear, complete request, generate immediately without unnecessary back-and-forth.

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Code Standards — ALWAYS Follow These

Separation of Concerns

• Service classes contain business logic. They call Selectors for data and may call Domain classes for SObject-specific behavior.
• Selector classes encapsulate all SOQL queries. Services never contain inline SOQL.
• Domain classes encapsulate SObject-specific logic (field defaults, validation, transformation).
• Keep classes focused on a single responsibility.

Bulkification

• All methods must operate on collections (List, Set, Map) by default.
• Never accept a single SObject when a List<SObject> is appropriate.
• Provide convenience overloads for single-record callers only when it makes the API cleaner, and have them delegate to the bulk method.

Governor Limit Safety

• No SOQL or DML inside loops. Ever.
• Collect IDs/records first, query/DML once outside the loop.
• Use Limits class checks in batch/bulk operations where appropriate.
• Prefer Database.insert(records, false) with error handling in batch contexts.

Sharing Model

• Default to with sharing unless the user specifies otherwise.
• If without sharing or inherited sharing is used, add an ApexDoc @description comment explaining WHY.

Naming Conventions

Class Type	Pattern	Example
Service	{SObject}Service	AccountService
Selector	{SObject}Selector	AccountSelector
Domain	{SObject}Domain	OpportunityDomain
Batch	{Descriptive}Batch	AccountDeduplicationBatch
Queueable	{Descriptive}Queueable	ExternalSyncQueueable
Schedulable	{Descriptive}Schedulable	DailyCleanupSchedulable
DTO	{Descriptive}DTO	AccountMergeRequestDTO
Wrapper	{Descriptive}Wrapper	OpportunityLineWrapper
Utility	{Descriptive}Util	StringUtil, DateUtil
Interface	I{Descriptive}	INotificationService
Abstract	Abstract{Descriptive}	AbstractIntegrationService
Exception	{Descriptive}Exception	AccountServiceException

ApexDoc Comments

Include ApexDoc on every public and global method and on the class itself:

/**
 * @description Brief description of what the class does
 * @author Generated by Apex Class Writer Skill
 */

/**
 * @description Brief description of what the method does
 * @param paramName Description of the parameter
 * @return Description of the return value
 * @example
 * List<Account> results = AccountService.deduplicateAccounts(accountIds);
 */

Null Safety

• Use guard clauses at the top of methods for null/empty inputs.
• Use safe navigation (?.) where appropriate.
• Return empty collections rather than null.

Constants

• No magic strings or numbers in logic.
• Use private static final constants or a dedicated constants class.
• Use Label. custom labels for user-facing strings when appropriate.

Custom Exceptions

• Each service class should define or reference a corresponding custom exception.
• Inner exception classes are preferred for simple cases: public class AccountServiceException extends Exception {}
• Include meaningful error messages with context.

Error Handling

• Catch specific exceptions, not generic Exception unless re-throwing.
• Log errors meaningfully (assume a logging utility exists or stub one).
• In batch contexts, use Database.SaveResult / Database.UpsertResult with partial success.

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Output Format

For every class, produce TWO files:

1. {ClassName}.cls — The Apex class source code
2. {ClassName}.cls-meta.xml — The metadata file

Meta XML Template

<?xml version="1.0" encoding="UTF-8"?>
<ApexClass xmlns="http://soap.sforce.com/2006/04/metadata">
    <apiVersion>{API_VERSION}</apiVersion>
    <status>Active</status>
</ApexClass>

Default apiVersion is 62.0 unless the user specifies otherwise.

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Class Type–Specific Instructions

Service Classes

• Read and follow: templates/service.cls
• Stateless — no instance variables holding mutable state
• All public methods should be static unless there's a compelling reason for instance methods
• Delegate queries to a Selector class
• Wrap business logic errors in a custom exception

Selector Classes

• Read and follow: templates/selector.cls
• One Selector per SObject (or per logical query domain)
• Return List<SObject> or Map<Id, SObject>
• Accept filter criteria as method parameters, not hardcoded
• Include a private method that returns the base field list to keep DRY

Domain Classes

• Read and follow: templates/domain.cls
• Encapsulate field-level defaults, derivations, and validations
• Operate on List<SObject> — designed to be called from triggers or services
• No SOQL or DML — only in-memory SObject manipulation

Batch Classes

• Read and follow: templates/batch.cls
• Implement Database.Batchable<SObject> and optionally Database.Stateful
• Use Database.QueryLocator in start() for large datasets
• Handle partial failures in execute() using Database.SaveResult
• Implement meaningful finish() — at minimum, log completion

Queueable Classes

• Read and follow: templates/queueable.cls
• Implement Queueable and optionally Database.AllowsCallouts
• Accept data through the constructor — queueables are stateful
• For chaining, include guard logic to prevent infinite chains
• Optionally implement Finalizer for error recovery

Schedulable Classes

• Read and follow: templates/schedulable.cls
• Implement Schedulable
• Keep execute() lightweight — delegate to a Batch or Queueable
• Include a static method that returns a CRON expression for convenience
• Document the expected schedule in ApexDoc

DTO / Wrapper Classes

• Read and follow: templates/dto.cls
• Use public properties — no getters/setters unless validation is needed
• Include a no-arg constructor and optionally a parameterized constructor
• Implement Comparable if sorting is needed
• Keep them serialization-friendly (no transient state unless intentional)

Utility Classes

• Read and follow: templates/utility.cls
• All methods public static
• Class should be public with sharing with a private constructor to prevent instantiation
• Group related utilities (e.g., StringUtil, DateUtil, CollectionUtil)
• Every method must be side-effect-free (no DML, no SOQL)

Interfaces

• Read and follow: templates/interface.cls
• Define the contract clearly with ApexDoc on every method signature
• Use meaningful names that describe the capability: INotificationService, IRetryable

Abstract Classes

• Read and follow: templates/abstract.cls
• Provide default implementations for common behavior
• Mark extension points as protected virtual or protected abstract
• Include a concrete example in the ApexDoc showing how to extend

Custom Exceptions

• Read and follow: templates/exception.cls
• Extend Exception
• Keep them simple — Apex exceptions don't support custom constructors well
• Name them descriptively: AccountServiceException, IntegrationTimeoutException

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Generation Workflow

1. Determine the class type from the user's request
2. Read the corresponding template from templates/
3. Read relevant examples from examples/ if the class type has one
4. Apply the user's requirements to the template pattern
5. Generate the .cls file with full ApexDoc
6. Generate the .cls-meta.xml file
7. Present both files to the user
8. Include a brief note on design decisions if any non-obvious choices were made

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Anti-Patterns to Avoid

• ❌ SOQL or DML inside loops
• ❌ Hardcoded IDs or record type names (use Schema.SObjectType or Custom Metadata)
• ❌ God classes that mix query + logic + DML
• ❌ public fields on service classes
• ❌ Returning null from methods that should return collections
• ❌ Generic catch (Exception e) without re-throwing or meaningful handling
• ❌ Business logic in Batch start() methods
• ❌ Tight coupling between classes — use interfaces for extensibility
• ❌ Magic strings or numbers
• ❌ Methods longer than ~40 lines — break them into private helpers