// config/subscribd.php
'plans' => [
    'team' => [
        'name'           => 'Team',
        'rule'           => 'per_unit',
        'amount'         => 800,         // $8.00 per seat/month in cents
        'currency'       => 'USD',
        'interval'       => 'month',
        'interval_count' => 1,
        'features'       => [
            'seats'   => null,           // unlimited seats; quantity drives the price
            'support' => 'standard',
        ],
    ],
],

use Pixelworxio\Subscribd\Actions\CreateSubscription;
use Pixelworxio\Subscribd\Models\Plan;

$plan = Plan::query()->where('key', 'team')->firstOrFail();

app(CreateSubscription::class)->execute($team, $plan, [
    'plan_items' => ['seats' => $team->members()->count()],
]);

use Pixelworxio\Subscribd\Actions\UpdateQuantity;

// After a new member joins
app(UpdateQuantity::class)->execute($subscription->items->firstWhere('key', 'seats'), $newCount);

use Pixelworxio\Subscribd\Pricing\QuantityResolverRegistry;

app(QuantityResolverRegistry::class)->register(
    'team',
    fn ($team, $plan) => $team->members()->where('active', true)->count(),
);

'plan_items' => [
    [
        'key'           => 'seats',
        'cap_behaviour' => 'hard',    // reject over-limit additions
        'ceiling'       => 50,        // max 50 seats
        'included'      => 5,         // first 5 included in base price
        'overage_price' => 1500,      // $15.00 per seat above 5
    ],
],

use Pixelworxio\Subscribd\Facades\Entitlements;

$seatLimit = Entitlements::for($team)->limit('seats');
// Returns null (unlimited) or int

$seatsUsed = $team->members()->count();

if ($seatLimit !== null && $seatsUsed >= $seatLimit) {
    abort(403, 'Seat limit reached. Upgrade to add more members.');
}