# How it works Vexy consists of [Listings](/listings.md) and [Offers](/offers.md). In both cases, users retain custody of their NFTs and fungible tokens until a sale is consummated. Buyers and sellers simply grant allowances to the Vexy marketplace contract when creating listings and offers. Security is ensured by only allowing a small number of whitelisted currencies and NFTs to be traded. Currently, purchases can be made using USDC, WETH, and the underlying escrowed token (AERO or VELO). We look forward to supporting additional tokens in the future as the market grows. Prices are denominated in the token chosen by the seller and this same token must be used by the buyer. For example, a seller may choose to list veAERO for some amount of USDC. This will cause the discount rate to fluctuate with AERO/USDC volatility. But a buyer will be required to pay the same amount of USDC specified in the listing. Pro tip: it's much simpler if we all just buy and sell using AERO. --- # 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://docs.vexy.fi/how-it-works.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.