Setting up dynamic pricing in 1C-Bitrix

Configuration of Dynamic Pricing in 1C-Bitrix

Dynamic pricing is when price changes automatically per rules: depending on demand, inventory, competitors, time of day or user behavior. Unlike discounts and promotions, here price in b_catalog_price can change multiple times per day. Implementation requires understanding how Bitrix applies prices and clear rule architecture.

How Bitrix calculates final price

Calculation chain: base price (b_catalog_price) → catalog discounts (b_catalog_discount) → cart rules (b_sale_discount) → total. Dynamic pricing works at first level — changes base price, or intercepts via OnGetOptimalPrice event and returns different value.

Second option (via event) is preferable: doesn't pollute price history in b_catalog_price, doesn't affect price indexing, easier to rollback.

Dynamic pricing rules

Rules stored in custom table bl_dynamic_pricing_rules:

Event handler

AddEventHandler('catalog', 'OnGetOptimalPrice', function(&$fields) {
    $productId = $fields['PRODUCT_ID'];
    $basePrice = $fields['PRICE']['PRICE'] ?? null;

    if (!$basePrice) return;

    $modifier = DynamicPricingEngine::getModifier($productId);
    if ($modifier && $modifier != 1.0) {
        $fields['PRICE']['PRICE']      = round($basePrice * $modifier, 2);
        $fields['PRICE']['BASE_PRICE'] = $basePrice; // original for discount display
    }
});

DynamicPricingEngine::getModifier() loads applicable rules from cache (\Bitrix\Main\Data\Cache, TTL 300 sec) and calculates result coefficient. With multiple rules — multiply or take minimum/maximum depending on business logic.

Stock-based rule

If product stock falls below threshold — raise price (encourage early purchase or limit rush). Get inventory from b_catalog_store_product via \Bitrix\Catalog\StoreProductTable:

$stock = \Bitrix\Catalog\StoreProductTable::getList([
    'filter'  => ['PRODUCT_ID' => $productId],
    'select'  => ['AMOUNT'],
    'runtime' => [new \Bitrix\Main\ORM\Fields\ExpressionField('TOTAL', 'SUM(%s)', 'AMOUNT')],
])->fetch()['TOTAL'] ?? 0;

if ($stock < 5) return 1.2;   // +20% at stock < 5 units
if ($stock < 20) return 1.1;  // +10% at stock < 20 units
return 1.0;

Caching and performance

Event OnGetOptimalPrice is called on every price render — in catalog, on detail page, in cart. Without cache one catalog page with 48 products makes 48 DB calls. Cache modifier by PRODUCT_ID with TTL 5 minutes. When inventory or rules change — clear cache by tag dynamic_price_{productId}.

What to configure

• bl_dynamic_pricing_rules table with rule set
• DynamicPricingEngine class with caching and rule application logic
• OnGetOptimalPrice event handler in init.php or module
• Admin interface for rule management
• Price change logging in bl_dynamic_pricing_log for audit