Price synchronization with dropshipping supplier

Implementation of Price Synchronization with Dropshipping Supplier

Supplier prices change on schedule (new price list once a week) or in realtime (exchange-dependent goods, dynamic pricing). In both cases, store cannot work with outdated prices — either loses margin when supplier price rises, or charges excessive prices when it falls, losing to competitors.

Price Sources

• REST API — endpoint with current prices, can query frequently
• FTP/CSV price list — file updated once a day or less
• Webhook from supplier — push on every price change
• Website parsing — last resort without API (requires maintenance)

Storing Price History

Schema::create('dropship_price_log', function (Blueprint $table) {
    $table->id();
    $table->foreignId('dropship_product_id')->constrained();
    $table->decimal('prev_supplier_price', 10, 2);
    $table->decimal('new_supplier_price', 10, 2);
    $table->decimal('prev_retail_price', 10, 2)->nullable();
    $table->decimal('new_retail_price', 10, 2)->nullable();
    $table->decimal('margin_percent', 5, 2)->nullable();
    $table->string('source')->default('sync');
    $table->timestamp('recorded_at');

    $table->index(['dropship_product_id', 'recorded_at']);
});

Retail Price Calculator

Retail price is calculated from wholesale with margin rules applied. Rules can be global, supplier-level, category, or product-specific.

class PriceCalculator
{
    public function calculate(DropshipProduct $dp): float
    {
        $supplierPrice = $dp->supplier_price;
        $marginRule    = $this->resolveMarginRule($dp);

        return match($marginRule->type) {
            'percent' => round($supplierPrice * (1 + $marginRule->value / 100), 2),
            'fixed'   => round($supplierPrice + $marginRule->value, 2),
            'markup_table' => $this->applyMarkupTable($supplierPrice, $marginRule->table),
        };
    }

    private function resolveMarginRule(DropshipProduct $dp): MarginRule
    {
        // Priority: product > category > supplier > global
        return $dp->margin_rule
            ?? $dp->product?->category?->margin_rule
            ?? $dp->supplier->margin_rule
            ?? MarginRule::getDefault();
    }

    /**
     * Tiered markup: expensive items — lower %
     * [up to 1000 → +40%, 1000–5000 → +25%, 5000+ → +15%]
     */
    private function applyMarkupTable(float $price, array $table): float
    {
        foreach ($table as $tier) {
            if ($price <= $tier['max_price']) {
                return round($price * (1 + $tier['percent'] / 100), 2);
            }
        }

        // Last level without max limit
        $last = end($table);
        return round($price * (1 + $last['percent'] / 100), 2);
    }
}

Price Sync Job

class SyncSupplierPricesJob implements ShouldQueue
{
    public $tries = 3;
    public $backoff = [60, 300, 900];

    public function handle(
        SupplierConnectorFactory $factory,
        PriceCalculator $calculator,
    ): void {
        $connector  = $factory->make($this->supplier);
        $priceList  = $connector->getPriceList(); // array [sku => price]
        $updatedCount = 0;

        foreach ($priceList as $sku => $newSupplierPrice) {
            $dp = DropshipProduct::where([
                'supplier_id'  => $this->supplier->id,
                'supplier_sku' => $sku,
            ])->first();

            if (!$dp) continue;

            // Skip if price unchanged
            if (abs($dp->supplier_price - $newSupplierPrice) < 0.01) continue;

            $prevSupplierPrice = $dp->supplier_price;
            $prevRetailPrice   = $dp->product?->price;

            $dp->update(['supplier_price' => $newSupplierPrice]);

            // Recalculate retail price if not manually locked
            $newRetailPrice = null;
            if ($dp->product && !$dp->product->price_locked) {
                $newRetailPrice = $calculator->calculate($dp);
                $dp->product->update(['price' => $newRetailPrice]);
            }

            DropshipPriceLog::create([
                'dropship_product_id' => $dp->id,
                'prev_supplier_price' => $prevSupplierPrice,
                'new_supplier_price'  => $newSupplierPrice,
                'prev_retail_price'   => $prevRetailPrice,
                'new_retail_price'    => $newRetailPrice,
                'source'              => 'sync',
                'recorded_at'         => now(),
            ]);

            $updatedCount++;
        }

        Log::info('Price sync completed', [
            'supplier' => $this->supplier->slug,
            'updated'  => $updatedCount,
        ]);
    }
}

Protection from Drastic Price Changes

Sometimes supplier price list has errors (zero, very high, typo). Without protection, store shows incorrect retail price:

class PriceSanityChecker
{
    private const MAX_CHANGE_PERCENT = 50; // don't update if change > 50%

    public function isSafe(float $prevPrice, float $newPrice): bool
    {
        if ($newPrice <= 0) return false;

        if ($prevPrice <= 0) return true; // first price — accept any positive

        $changePercent = abs($newPrice - $prevPrice) / $prevPrice * 100;

        if ($changePercent > self::MAX_CHANGE_PERCENT) {
            // Log for manual review
            Log::warning('Suspicious price change detected', [
                'prev'    => $prevPrice,
                'new'     => $newPrice,
                'change%' => round($changePercent, 1),
            ]);
            return false;
        }

        return true;
    }
}

Products with suspicious price changes go to manual review queue — manager sees them in separate admin section.

Currency and Exchange Rate Conversions

If supplier sets prices in USD or EUR, but store works in RUB:

class CurrencyPriceConverter
{
    public function convert(float $price, string $fromCurrency, string $toCurrency): float
    {
        if ($fromCurrency === $toCurrency) return $price;

        $rate = Cache::remember(
            "exchange_rate_{$fromCurrency}_{$toCurrency}",
            3600, // cache 1 hour
            fn() => $this->fetchRate($fromCurrency, $toCurrency)
        );

        return round($price * $rate, 2);
    }

    private function fetchRate(string $from, string $to): float
    {
        // CBR RF: cbr.ru/scripts/XML_daily.asp
        // Or openexchangerates.org, fixer.io
        $response = Http::get('https://api.exchangerate-api.com/v4/latest/' . $from);
        return $response->json("rates.{$to}");
    }
}

Schedule

// Price sync every 6 hours
$schedule->job(SyncAllSupplierPricesJob::class)->everySixHours()->withoutOverlapping();

Timeline

Price sync with one supplier + margin calculator — 3–4 business days. Tiered markup, exchange rate conversion, change protection — another 1–2 days.