> For the complete documentation index, see [llms.txt](https://docs.extrafi.io/extrafi-xlend/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.extrafi.io/extrafi-xlend/borrow-lend/price-feed.md). # Price Feed ## Oracle Chainlink is the primary Oracle used in XLend. Chainlink oracles provide highly reliable, decentralized price data for various assets. These price feeds aggregate data from multiple sources, minimizing the risk of manipulation or outages. XLend uses Chainlink Oracle as a price feed within the protocol for calculating collateral value, debt value, and liquidation thresholds. {% embed url="" %} ## Oracle Sentinel Oracle Sentinel validates whether operations are allowed based on the Oracle's health status. This feature introduces a grace period for liquidations and disables borrowing under specific circumstances. It has been designed specifically for L2s to handle potential sequencer downtime. After an Oracle outage or downtime, users can improve their positions' health during a grace period. The Oracle is considered healthy once fully operational and the grace period has elapsed. ## Oracle Usage We've implemented a monitoring system to detect Oracle manipulation and abnormal price feeds, to protect the protocol from malicious behaviors, including: * Flash loan activity detection * Abnormal price movement detection Once the risk team confirms that the Oracle is been manipulated, necessary actions will be taken to mitigate the impact including a liquidation pause. --- # 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.extrafi.io/extrafi-xlend/borrow-lend/price-feed.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.