> For the complete documentation index, see [llms.txt](https://ethereals-blockchain.gitbook.io/ethereal-chain-documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ethereals-blockchain.gitbook.io/ethereal-chain-documentation/industry-use-cases/nft-marketplaces.md). # NFT Marketplaces Build a marketplace for digital collectibles that customers can buy, trade, and share on a carbon-neutral blockchain with 0 gas fees. Non-Fungible Tokens (NFTs) have captured the imagination of the Web3 community. While the most powerful NFT use cases might still be to come, this technology is already transforming digital ownership, identity, creative expression, and community membership. Because NFTs are digital assets that can be bought, sold, or traded, NFT marketplaces play an important role in holding inventory and connecting buyers and sellers. In this blog, we are going to build the “backend” of an NFT marketplace using Solidity. We’ll go through the process for building the smart contracts that hold the business logic for our NFT marketplace step-by-step. In practice, this means creating a single `NftMarketplace.sol` smart contract and a sample ERC721-compliant token (NFT) contract which we can use to list on our 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://ethereals-blockchain.gitbook.io/ethereal-chain-documentation/industry-use-cases/nft-marketplaces.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.