Service Layer

Service Layer

Services are the only place business logic lives. They are framework-agnostic.

1. Responsibility

Services MUST:

• contain business logic
• coordinate models
• enforce domain rules
• return models or DTOs

Services MUST NOT:

• accept or return HTTP request/response objects
• contain UI logic
• use app() or resolve() internally

2. Dependency Rule

Constructor injection only:

public function __construct(
    private InvoiceRepository $repository
) {}

3. DTO Rule

DTOs are not required when the source is a validated FormRequest::validated() array. Arrays are fine there.

Use DTOs when:

• crossing system boundaries (API, queues, external integrations)
• multiple services share a contract
• the payload must be stable across refactors

Skip DTOs when:

• input comes from a single controller action's validated request
• the data is short-lived and not reused

4. Standard Shape

app/Services/{Domain}/{Model}Service.php

e.g. app/Services/Task/TaskService.php, app/Services/Offer/OfferService.php.

Standard method names: create, update, delete, findByExternalId. Prefer one service class per domain holding both create/update (see TaskService) over splitting into separate per-action service classes.