Login As Customer (LAC) Decoupling Report¶

Modules Scanned (10 modules, 95 PHP files total)¶

Module	Files	Role
`LoginAsCustomerApi`	17	API interfaces + service contracts (only depends on Framework)
`LoginAsCustomer`	20	Core logic — authentication, admin login action
`LoginAsCustomerAdminUi`	8	Admin UI — buttons, columns in customer/order grid
`LoginAsCustomerAssistance`	18	Shopping assistance consent + admin notices
`LoginAsCustomerFrontendUi`	6	Frontend UI — confirmation popup, notifications
`LoginAsCustomerGraphQl`	5	GraphQL resolvers for LAC
`LoginAsCustomerLog`	14	Login logging + admin log grid
`LoginAsCustomerPageCache`	2	Page cache context handling for LAC sessions
`LoginAsCustomerQuote`	2	Quote cleanup on LAC session start
`LoginAsCustomerSales`	3	Order notes — marks orders placed during LAC

Can It Be Removed Entirely? YES — trivially¶

Only 1 external module has any dependency on LAC. Zero PHP imports exist outside the LAC family.

External Coupling¶

Persistent Module — 1 plugin, 1 PHP import, 1 composer dep¶

Type	Detail
`Persistent/composer.json`	`"magento/module-login-as-customer-api": "*"` (hard require)
`Persistent/etc/frontend/di.xml:61`	Plugin on `LoginAsCustomerApi\Api\AuthenticateCustomerBySecretInterface`
`Persistent/Model/Plugin/LoginAsCustomerCleanUp.php`	`use Magento\LoginAsCustomerApi\Api\AuthenticateCustomerBySecretInterface`

What it does: When an admin logs in as a customer, Persistent clears the persistent cookie to prevent session confusion.

Fix: Move this plugin from Persistent into one of the LAC modules (e.g., LoginAsCustomer or a new LoginAsCustomerPersistent bridge). The plugin is about LAC behavior, not Persistent behavior — it belongs in the LAC module family. Persistent then drops its LAC dependency.

That's it. No other external module references LAC in any way.

Internal Architecture (Already Well-Designed)¶

The 10 modules follow a clean layered pattern:

LoginAsCustomerApi (pure interfaces — depends only on Framework)
    ↑
    │ All other LAC modules depend on Api
    │
LoginAsCustomer (core logic)
    ↑
    ├── LoginAsCustomerAdminUi (admin buttons/grid columns)
    ├── LoginAsCustomerAssistance (consent management)
    ├── LoginAsCustomerFrontendUi (frontend popup/notifications)
    ├── LoginAsCustomerGraphQl (GraphQL layer)
    ├── LoginAsCustomerLog (audit logging)
    ├── LoginAsCustomerPageCache (cache context)
    ├── LoginAsCustomerQuote (quote cleanup)
    └── LoginAsCustomerSales (order annotation)

Key design decisions done right: - LoginAsCustomerApi has zero module dependencies (only Framework) — the perfect API module - Each sub-module is single-responsibility (PageCache handles caching, Quote handles quotes, Sales handles orders) - Sub-modules only depend on LoginAsCustomerApi (interface layer), not on each other (except AdminUi→FrontendUi and Assistance→AdminUi) - Every sub-module can be disabled independently

Dependencies on Core Modules¶

LAC Module	Core Module Dependencies
Api	Framework only
Core	Backend, Customer, User, Authorization
AdminUi	Backend, Customer, Sales, Store
Assistance	Authorization, Backend, Customer, Store
FrontendUi	Customer, Store, Checkout
GraphQl	Integration, Store, Customer
Log	Backend, Customer, Ui, User
PageCache	Store, PageCache
Quote	Checkout, Customer, Quote
Sales	Backend, User, Sales

All core dependencies are appropriate — each LAC module depends on exactly the modules it interacts with.

Decoupling Plan¶

Phase 1: Move Persistent Plugin to LAC (only change needed)¶

Move FROM Persistent/ TO LoginAsCustomer/ (or LoginAsCustomerApi/):

Current	New
`Persistent/Model/Plugin/LoginAsCustomerCleanUp.php`	`LoginAsCustomer/Plugin/Persistent/CleanUp.php`
`Persistent/etc/frontend/di.xml` (plugin registration)	`LoginAsCustomer/etc/frontend/di.xml`

Add magento/module-persistent to LoginAsCustomer/composer.json as suggest (plugin only activates when Persistent is installed).

Remove magento/module-login-as-customer-api from Persistent/composer.json.

Phase 2: Verify Clean Removal¶

After Phase 1, disabling all 10 LAC modules means: - No "Login as Customer" button in admin customer/order grids - No shopping assistance consent - No LAC session handling or logging - Persistent, Customer, Sales, Quote, Checkout — zero impact - All 10 modules can be removed via composer with zero side effects

Difficulty Assessment¶

Phase	Effort	Risk
Move 1 plugin + 1 DI registration	Trivial	Zero
Overall	Trivial	LAC is already near-perfect

Verdict¶

LoginAsCustomer is the second-best-designed module family in Magento (after ApplicationPerformanceMonitor). Clean API separation, single-responsibility sub-modules, minimal external coupling (1 plugin in 1 module). The only fix is a single plugin relocation.

This should be the reference architecture for how to build optional Magento feature modules.