⛓️ Blockchain & Web3 · C4 Architecture · Pro
NFT Marketplace
How an NFT marketplace works: listings signed off-chain, metadata on IPFS, and sales settled by a marketplace smart contract.
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Drawing diagram…
What this diagram shows
- Listings are signed messages, so listing costs no gas
- Artwork and metadata live on IPFS, not the marketplace's servers
- The smart contract pays the seller and creator royalty in one step
Prompt used
NFT marketplace: users connect wallets (MetaMask) to a web app. Creators mint NFTs through a minting contract with metadata and images pinned on IPFS. Sellers sign listings off-chain, stored in the marketplace API. Buyers call the marketplace smart contract, which checks the signature, transfers the NFT, pays the seller and the creator royalty. An indexer reads blockchain events into PostgreSQL for search.
Mermaid code
C4Container
title NFT Marketplace
Person(user, "Collector / Creator", "Buys, sells, mints")
System_Boundary(mp, "Marketplace") {
Container(web, "Web App", "Next.js", "Browse, list, buy")
Container(api, "Marketplace API", "Node.js", "Signed listings, search")
Container(idx, "Chain Indexer", "Go", "Reads contract events")
ContainerDb(db, "Market DB", "PostgreSQL", "Listings, sales, collections")
}
System_Ext(wallet, "Wallet", "MetaMask")
System_Ext(chain, "Ethereum", "Marketplace and NFT contracts")
System_Ext(ipfs, "IPFS", "Images and metadata")
Rel(user, web, "Uses")
Rel(web, wallet, "Signs listings and transactions")
Rel(web, api, "Listings and search")
Rel(wallet, chain, "Sends transactions")
Rel(web, ipfs, "Uploads artwork")
Rel(idx, chain, "Reads events")
Rel(idx, db, "Writes sales")
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