Cashier Paddle Laravel Package

Technical Evaluation

Architecture Fit

• Seamless Laravel Integration: Designed as a Cashier extension, it inherits Laravel’s Eloquent-based billing patterns, ensuring consistency with existing Laravel applications (e.g., User model subscriptions via hasOne relationships).
• Paddle Abstraction: Encapsulates Paddle’s API complexity (webhooks, subscriptions, invoices) behind a fluent interface, reducing custom integration effort.
• Event-Driven Hooks: Leverages Laravel’s event system (e.g., SubscriptionCreated, InvoicePaid) for extensibility, aligning with modern Laravel architectures.
• Database Agnostic: Works with Laravel’s query builder, supporting all supported databases (MySQL, PostgreSQL, SQLite).

Integration Feasibility

• Low-Coupling Design: Minimal invasive changes required; integrates via Cashier facade or service provider binding.
• Webhook Handling: Requires Paddle webhook endpoint setup (Laravel routes + middleware) but provides a PaddleWebhookHandler trait for validation.
• Testing Support: Includes Laravel’s testing helpers (e.g., actingAs, assertPaid) and mockable HTTP clients for CI/CD pipelines.
• Multi-Tenant Ready: Supports scoping subscriptions to tenants via Laravel’s globalScope or package-specific middleware.

Technical Risk

• Paddle API Dependencies: Risk of breaking changes if Paddle alters its API (e.g., deprecated endpoints, new auth requirements). Mitigate via:
  • Semantic versioning adherence (package follows Laravel’s release cadence).
  • Community-driven updates (264 stars, active maintainers).
• Webhook Reliability: Misconfigured webhooks or rate limits may disrupt billing flows. Requires:
  • Idempotency testing for webhook retries.
  • Monitoring (e.g., Laravel Horizon for failed job tracking).
• Legacy System Gaps: May not cover niche Paddle features (e.g., custom tax rules). Requires:
  • Direct Paddle API fallback for unsupported use cases.
  • Feature gap documentation in the README.

Key Questions

1. Subscription Model: Does the app use Eloquent models for subscriptions, or is a custom table preferred? (Cashier assumes users table with stripe_id; Paddle uses paddle_customer_id.)
2. Webhook Security: How will Paddle webhook signatures be validated? (Package provides PaddleWebhookHandler but requires HMAC setup.)
3. Multi-Currency: Does the app need multi-currency support? (Paddle handles this natively; package may need extension.)
4. Offline Payments: Are there manual payment methods (e.g., bank transfers) requiring custom flows?
5. Audit Logging: Are there compliance requirements for subscription changes? (Package lacks built-in audit trails; may need Laravel logging middleware.)
6. Performance: Will high subscription volumes stress the database? (Cashier’s subscriptions table may need indexing for user_id + status.)

Integration Approach

Stack Fit

• Laravel Ecosystem: Optimized for Laravel 10+ (PHP 8.1+), leveraging:
  • Eloquent: Subscription models inherit Billable trait.
  • Queues: Async webhook processing via Laravel queues.
  • Testing: Pest/PHPUnit support with Cashier assertions.
• Paddle Compatibility: Requires:
  • Paddle merchant account (sandbox/testing recommended pre-launch).
  • Paddle API keys (stored in .env or Laravel vault).
• Third-Party Tools:
  • Stripe Alternative: Direct replacement for laravel/cashier-stripe if migrating from Stripe.
  • Payment Gateways: Works alongside other Cashier drivers (e.g., cashier-mollie) via Laravel’s service container.

Migration Path

1. Preparation:
   • Add Paddle merchant account and API keys to .env.
   • Install package: composer require laravel/cashier-paddle.
   • Publish config: php artisan vendor:publish --provider="Laravel\CashierPaddle\CashierPaddleServiceProvider".
2. Model Integration:
   • Add use Laravel\CashierPaddle\Billable; to user model.
   • Migrate stripe_id column to paddle_customer_id (or add new column).
3. Webhooks:
   • Route Paddle webhooks to PaddleWebhookHandler (e.g., POST /paddle/webhook).
   • Configure Paddle dashboard with your webhook URL.
4. Testing:
   • Use Paddle sandbox for integration tests.
   • Test edge cases: failed payments, subscription swaps, cancellations.
5. Go-Live:
   • Switch from sandbox to live Paddle API.
   • Monitor webhook delivery and subscription statuses.

Compatibility

• Laravel Versions: Tested on Laravel 10+ (PHP 8.1+). May require polyfills for older versions.
• Database: Supports all Laravel-supported databases but assumes subscriptions table exists (created via php artisan migrate if using Cashier).
• PHP Extensions: Requires cURL and OpenSSL for API calls.
• Caching: Leverages Laravel’s cache for rate-limiting (configurable in config/cashier.php).

Sequencing

1. Phase 1: Core Subscriptions
   • Implement newSubscription() and subscription() methods.
   • Test basic flows: create, pause, cancel, resume.
2. Phase 2: Webhooks
   • Set up webhook routes and handlers.
   • Validate signature and process events (e.g., subscription_canceled).
3. Phase 3: Advanced Features
   • Add coupon/pricing logic via Paddle\Paddle facade.
   • Implement custom invoice PDFs or dunning management.
4. Phase 4: Monitoring
   • Log webhook failures to Sentry/Laravel logs.
   • Set up alerts for high cancellation rates.

Operational Impact

Maintenance

• Updates: Follow Laravel’s release schedule (package aligns with Cashier updates).
  • Minor updates: Composer auto-update.
  • Major updates: Test Paddle API compatibility (e.g., breaking changes in v2026).
• Dependency Management:
  • Monitor laravel/cashier and paddle/sdk-php for breaking changes.
  • Use composer why-not to audit dependency conflicts.
• Documentation:
  • Maintain internal runbooks for:
    • Webhook troubleshooting (e.g., retry logic).
    • Paddle API rate limits (e.g., 60 requests/minute).

Support

• Debugging Tools:
  • Enable Paddle debug mode (config/cashier.php['debug'] = true).
  • Use Paddle::debug() to log API requests/responses.
• Common Issues:
  • Webhook Failures: Retry logic via Laravel queues; monitor failed_jobs table.
  • Subscription Sync: Run php artisan cashier:sync to reconcile database with Paddle.
  • Payment Retries: Configure Paddle’s retry settings (e.g., 3 attempts).
• Vendor Lock-In: Mitigate by:
  • Abstracting Paddle-specific logic behind interfaces.
  • Documenting custom Paddle features for future migrations.

Scaling

• Database:
  • Index subscriptions table on user_id, status, and trial_ends_at.
  • Consider read replicas for high-traffic subscription queries.
• Webhooks:
  • Use Laravel Horizon for queue-based processing.
  • Scale horizontally if webhook volume exceeds PHP-FPM limits.
• API Rate Limits:
  • Cache Paddle API responses (e.g., customer data) with Cache::remember.
  • Implement exponential backoff for retries.
• Multi-Region:
  • Deploy Paddle webhook handlers in the same region as Paddle’s API endpoints (e.g., EU for GDPR compliance).

Failure Modes

Ramp-Up

• Onboarding Time: 2–5 days for basic integration (longer for custom features).
  • Team Skills: Requires familiarity with Laravel Eloquent, queues, and webhooks.
  • Training:
    • Walkthrough of CashierPaddle facade methods (