# Data Consistency Data consistency is critical in the checkout flow. The system applies the following principles: * **Cascading Invalidation**: When a change is made in a critical step (for example, address change), subsequent steps affected by this change are automatically reset. * **Precondition Checks**: Before accessing any step, it is verified whether previous steps have been completed. * **Session-based Storage**: Checkout information is stored temporarily until the order is completed and is automatically cleared when the session expires. --- # Agent Instructions: 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: ``` GET https://apidocs.akinon.com/commerce-openapis/checkout/checkout-overview/data-consistency.md?ask= ``` The question should be specific, self-contained, and written in natural language. 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.