Laravel Billing (Cashier)

Agent Workflow (MANDATORY)

Before ANY implementation, launch in parallel:

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:

Key Difference: MoR vs Payment Processor

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

Reference Guide

Concepts (WHY & Architecture)

Advanced SaaS Features

Templates (Complete Code)

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)