# Catalog Promo
There is a table which hold all product after promo rule
> catalogrule_product_price
The table look like this
| product_id | rule_price |
| -------- | --------- |
|604|287.1|
It is a observer of CatalogRule module to get apply the promo price to product data *final_price*
> Magento\CatalogRule\Observer\ProcessFrontFinalPriceObserver
it hooks on the event
> catalog_product_get_final_price
## Indexer
the builder which reponse for read/write ***catalogrule_product_price***
> Magento\CatalogRule\Model\Indexer::applyAllRules