> For the complete documentation index, see [llms.txt](https://sandcastle.gitbook.io/sand-castle-finance/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sandcastle.gitbook.io/sand-castle-finance/introduction/what-is-sandcastle.md). # What is SandCastle? [**Sand Castle**](https://sandcastle.finance/) offers permission-less lending and cross margin between ERC-20 tokens, flash loans, and all types of leveraged V3 positions. Our mission is to revolutionize the DeFi landscape by offering innovative solutions that maximize profitability and minimize risk. Through SandCastle, you can lend any token, create a leveraged Uniswap v3 position, borrow any type of token, or execute flash loans. All of the control is in your hands. **No limitations**. Click next to join us in revolutionizing DeFi. --- # 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://sandcastle.gitbook.io/sand-castle-finance/introduction/what-is-sandcastle.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.