Laravel Billing (Cashier)

Agent Workflow (MANDATORY)

Before ANY implementation, use TeamCreate to spawn 3 agents:

1. fuse-ai-pilot:explore-codebase - Check existing billing setup, User model
2. fuse-ai-pilot:research-expert - Verify latest Cashier docs via Context7
3. mcp__context7__query-docs - Query specific patterns (Stripe/Paddle)

After implementation, run fuse-ai-pilot:sniper for validation.

---

Overview

Laravel Cashier provides subscription billing with Stripe or Paddle. Choose based on your needs:

Provider	Package	Best For
Stripe	laravel/cashier	Full control, high volume, complex billing
Paddle	laravel/cashier-paddle	Tax handling, compliance, global sales

Key Difference: MoR vs Payment Processor

Aspect	Stripe	Paddle
Type	Payment Processor	Merchant of Record
Taxes	You manage (or Stripe Tax)	Paddle manages automatically
Invoices	Your company name	Paddle + your name
Compliance	Your responsibility	Paddle handles
Fees	~2.9% + $0.30	~5% + $0.50 (all-inclusive)

---

Critical Rules

1. Use webhooks - Never rely on client-side confirmations
2. Handle grace periods - Allow access until subscription ends
3. Never store card details - Use payment tokens/methods
4. Test with test keys - Always before production
5. Verify webhook signatures - Prevent spoofing attacks
6. Handle incomplete payments - 3D Secure requires user action

---

Architecture

app/
├── Http/
│   ├── Controllers/
│   │   └── Billing/              ← Billing controllers
│   │       ├── SubscriptionController.php
│   │       ├── CheckoutController.php
│   │       └── InvoiceController.php
│   └── Middleware/
│       └── EnsureSubscribed.php  ← Subscription check
├── Models/
│   └── User.php                  ← Billable trait
├── Listeners/
│   └── StripeEventListener.php   ← Webhook handling
└── Services/
    └── BillingService.php        ← Business logic

config/
├── cashier.php                   ← Stripe/Paddle config
└── services.php                  ← API keys

routes/
└── web.php                       ← Webhook routes (excluded from CSRF)

---

FuseCore Integration

When working in a FuseCore project, billing follows the modular structure:

FuseCore/
├── Core/                         # Infrastructure (priority 0)
│   └── App/Contracts/
│       └── BillingServiceInterface.php  ← Billing contract
│
├── User/                         # Auth module (existing)
│   └── App/Models/User.php       ← Add Billable trait here
│
├── Billing/                      # Billing module (new)
│   ├── App/
│   │   ├── Http/
│   │   │   ├── Controllers/
│   │   │   │   ├── SubscriptionController.php
│   │   │   │   ├── CheckoutController.php
│   │   │   │   └── WebhookController.php
│   │   │   └── Middleware/
│   │   │       └── EnsureSubscribed.php
│   │   ├── Listeners/
│   │   │   └── HandleWebhookEvents.php
│   │   └── Services/
│   │       └── BillingService.php
│   ├── Config/
│   │   └── cashier.php           ← Module-level config
│   ├── Database/Migrations/
│   ├── Routes/
│   │   ├── web.php               ← Webhooks (no CSRF)
│   │   └── api.php               ← Subscription management
│   └── module.json               # dependencies: ["User"]

FuseCore Billing Checklist

• Billing code in /FuseCore/Billing/ module
• Billable trait on User model in /FuseCore/User/
• Webhook routes in /FuseCore/Billing/Routes/web.php
• Exclude webhook from CSRF in VerifyCsrfToken
• Declare "User" dependency in module.json

→ See fusecore skill for complete module patterns.

---

Decision Guide

Stripe vs Paddle

Selling to businesses (B2B)? → Stripe
├── Need OAuth for third-party apps? → Stripe Connect
└── Selling to consumers (B2C) globally?
    ├── Want to handle taxes yourself? → Stripe + Stripe Tax
    └── Want tax compliance handled? → Paddle

Subscription vs One-Time

Recurring revenue? → Subscription
├── Fixed plans? → Single-price subscription
└── Usage-based? → Metered billing (Stripe) or quantity-based
Single purchase? → One-time charge
├── Digital product? → Checkout session
└── Service fee? → Direct charge

---

Key Concepts

Concept	Description	Reference
Billable	Trait that enables billing on a model	stripe.md
Subscription	Recurring billing cycle	subscriptions.md
Price ID	Stripe/Paddle price identifier	stripe.md
Grace Period	Time after cancellation with access	subscriptions.md
Webhook	Server-to-server payment notifications	webhooks.md
Customer Portal	Self-service billing management	checkout.md

---

Reference Guide

Concepts (WHY & Architecture)

Topic	Reference	When to Consult
Stripe Cashier	stripe.md	Stripe setup, configuration
Paddle Cashier	paddle.md	Paddle setup, differences
Subscriptions	subscriptions.md	Create, cancel, swap, pause
Webhooks	webhooks.md	Webhook security, handling
Invoices	invoices.md	PDF generation, receipts
Payment Methods	payment-methods.md	Cards, wallets, updates
Checkout	checkout.md	Hosted checkout, portal
Testing	testing.md	Test cards, webhook testing

Advanced SaaS Features

Topic	Reference	When to Consult
Metered Billing	metered-billing.md	Usage-based pricing (API, storage)
Team Billing	team-billing.md	Organization billing, per-seat
Dunning	dunning.md	Failed payment recovery
Feature Flags	feature-flags.md	Plan-based feature access

Templates (Complete Code)

Template	When to Use
UserBillable.php.md	User model with Billable trait
SubscriptionController.php.md	CRUD subscription operations
WebhookController.php.md	Custom webhook handling
CheckoutController.php.md	Stripe Checkout + Portal
InvoiceController.php.md	Invoice download
BillingRoutes.php.md	Complete route definitions
SubscriptionTest.php.md	Pest tests for billing
MeteredBillingController.php.md	Usage tracking and reporting
TeamBillable.php.md	Team model with seat management
DunningService.php.md	Payment recovery automation
FeatureFlags.php.md	Laravel Pennant per-plan features

---

Quick Reference

Check Subscription Status

// Has active subscription?
$user->subscribed('default');

// Subscribed to specific price?
$user->subscribedToPrice('price_premium', 'default');

// On trial?
$user->onTrial('default');

// Cancelled but still active?
$user->subscription('default')->onGracePeriod();

Create Subscription

// Simple subscription
$user->newSubscription('default', 'price_monthly')
    ->create($paymentMethodId);

// With trial
$user->newSubscription('default', 'price_monthly')
    ->trialDays(14)
    ->create($paymentMethodId);

Manage Subscription

$subscription = $user->subscription('default');

// Change plan
$subscription->swap('price_yearly');

// Cancel at period end
$subscription->cancel();

// Cancel immediately
$subscription->cancelNow();

// Resume cancelled subscription
$subscription->resume();

Billing Portal

// Redirect to customer portal (Stripe)
return $user->redirectToBillingPortal(route('dashboard'));

// Get portal URL
$url = $user->billingPortalUrl(route('dashboard'));

---

Best Practices

DO

• Use webhooks for payment confirmation
• Implement grace periods for cancelled subscriptions
• Set up webhook signature verification
• Handle IncompletePayment exceptions
• Test with Stripe CLI locally
• Prune old data regularly

DON'T

• Trust client-side payment confirmations
• Store card numbers (PCI compliance)
• Skip webhook verification
• Ignore failed payment webhooks
• Forget to handle 3D Secure
• Hardcode prices (use env or config)