> For the complete documentation index, see [llms.txt](https://base-tech.gitbook.io/base/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://base-tech.gitbook.io/base/10.-building-a-marketplace.md). # 10. Building a marketplace We have all the necessary tools to create our first full-fledged project. Given the current state of the cryptocurrency industry, an NFT marketplace would be an ideal choice. Marketplaces are highly sought after as they provide equal access to digital collectibles such as art, in-game items, virtual vouchers, and more. Blockchains offer open membership ledgers, and marketplaces provide a platform to trade assets on these ledgers freely. The following are some of the features: Tiny Market is a minimal implementation that enables people to trustlessly list NFTs for sale. An NFT offering includes the NFT for sale, the block height at which the listing expires, the payment asset, the NFT price in the payment asset, and an optional intended taker. If set, only the principal mentioned will be able to fulfill the listing. This feature is useful if someone has found a buyer outside of the platform and wants to conduct a trade with just that person in a trustless manner. The listing process does not involve any bidding or other complications. To create a listing, call the marketplace contract with the above information, and the contract will transfer the NFT and hold it in escrow for the duration of the listing. The seller has the option to cancel the listing and retrieve the NFT at any time. If a buyer decides to purchase the NFT, the marketplace will automatically process the payment and transfer the NFT. After a listing has expired, only the seller can retrieve the NFT from the marketplace. --- # 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://base-tech.gitbook.io/base/10.-building-a-marketplace.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.