> For the complete documentation index, see [llms.txt](https://docs.commercelayer.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.commercelayer.io/rules-engine/use-cases.md). # Use cases - [Promotions](https://docs.commercelayer.io/rules-engine/use-cases/promotions.md): A list of the most common application scenarios of Commerce Layer Rules Engine to the flex promotion resource - [Discount line items based on item's price](https://docs.commercelayer.io/rules-engine/use-cases/promotions/get-fixed-amount-off-price-gteq.md): Rule breakdown, resource payload analysis, and outcomes explanation - [Get a discount when paying by credit card](https://docs.commercelayer.io/rules-engine/use-cases/promotions/get-percentage-discount-credit-card.md): Rule breakdown, resource payload analysis, and outcomes explanation - [Discount an order based on promo item and total number of items](https://docs.commercelayer.io/rules-engine/use-cases/promotions/get-percentage-discount-promo-item-number-of-items-gteq.md): Rule breakdown, resource payload analysis, and outcomes explanation - [Offer a specific shipping method for free in a specific country](https://docs.commercelayer.io/rules-engine/use-cases/promotions/free-shipping-method-by-country.md): Rule breakdown, resource payload analysis, and outcomes explanation - [Discount items with large stock availability](https://docs.commercelayer.io/rules-engine/use-cases/promotions/get-percentage-discount-quantity-gteq.md): Rule breakdown, resource payload analysis, and outcomes explanation - [Discount all the SKU in an order based on the shipping country](https://docs.commercelayer.io/rules-engine/use-cases/promotions/get-percentage-discount-by-shipping-country.md): Rule breakdown, resource payload analysis, and outcomes explanation - [Discount all the SKU in an order based on the customer email domain](https://docs.commercelayer.io/rules-engine/use-cases/promotions/get-percentage-discount-by-email.md): Rule breakdown, resource payload analysis, and outcomes explanation - [Price lists](https://docs.commercelayer.io/rules-engine/use-cases/price-lists.md): A list of the most common application scenarios of Commerce Layer Rules Engine to the price list resource - [Discount all prices greater than or equal to a specific value](https://docs.commercelayer.io/rules-engine/use-cases/price-lists/discount-prices-gteq.md): Rule breakdown, resource payload analysis, and outcomes explanation - [Discount specific SKUs for new clients](https://docs.commercelayer.io/rules-engine/use-cases/price-lists/discount-specific-skus-for-new-clients.md): Rule breakdown, resource payload analysis, and outcomes explanation - [Change strike-through price based on customer email domain](https://docs.commercelayer.io/rules-engine/use-cases/price-lists/update-compare-at-price-by-email.md): Rule breakdown, resource payload analysis, and outcomes explanation --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.commercelayer.io/rules-engine/use-cases.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.