credits

Overview Modern SaaS pricing has shifted from feature-gating to consumption-based models. This approach, popular in AI-driven tools, allows users to pay for specific usage—like tokens or credits—on top of a recurring fee. Implementing this in Laravel involves synchronizing local database records with Stripe subscription cycles to ensure users never exceed their allocated limits. Prerequisites To follow this guide, you should be comfortable with Laravel 10+, PHP 8.1+ features like Enums, and have a basic understanding of Stripe integration using Laravel Cashier. Key Libraries & Tools - **Laravel Cashier**: Manages subscriptions and webhooks. - **Stripe**: Handles the actual payment processing. - **Prism**: A package used here to interact with the Anthropic AI provider. - **PHP Enums**: Used to define static plan limits and pricing. Code Walkthrough 1. Database Schema Add fields to your `users` table to track the current balance and reset dates. ```php Schema::table('users', function (Blueprint $table) { $table->integer('credits_remaining')->default(100); $table->integer('credits_limit')->default(100); $table->timestamp('credits_reset_at')->nullable(); }); ``` 2. Credit Middleware Validate that a user has enough credits before they hit expensive API endpoints. ```php public function handle(Request $request, Closure $next) { if ($request->user()->credits_remaining < 1) { return back()->with('error', 'Insufficient credits.'); } return $next($request); } ``` 3. Deduction Logic Wrap the deduction in a service to keep your controllers clean and ensure transactions are logged. ```php public function deduct(User $user, int $amount) { $user->decrement('credits_remaining', $amount); $user->creditTransactions()->create([ 'amount' => $amount, 'type' => 'usage' ]); } ``` Syntax Notes This implementation uses **PHP Enums** to store plan details, making it easy to call `$plan->creditLimit()` anywhere in the app. It also relies on **Laravel Artisan Commands** to automate monthly resets by comparing the `credits_reset_at` timestamp with the current date. Practical Examples This system is ideal for **AI Content Generators** where each API call to models like Anthropic costs money. It also works for **Email Marketing Tools** that charge per 1,000 sent emails or **Image Processing** SaaS where high-resolution exports consume "points." Tips & Gotchas Avoid over-reliance on third-party wallet packages for simple credit needs; they can create dependency hell during Laravel upgrades. Always use **Stripe Webhooks** (specifically `invoice.payment_succeeded`) to trigger credit resets, ensuring users only get their new balance once payment clears.