FlashBid

FlashBid is a gasless, high-speed auction system powered entirely by ERC-7824 state channels, implemented using Yellow’s Nitrolite SDK. The core innovation is that all bidding occurs off-chain through signed messages, drastically reducing gas costs and latency. Once the auction ends, the winning bid is settled on-chain through a single trusted submission, preserving transparency and finality.

This system allows for real-time, low-latency auction experiences—ideal for NFT drops, token launches, or in-game assets—without the gas wars or frontrunning typical of on-chain auctions.

How it works: Auction Initialization: An auction is created with a predefined duration and reserve price.

Off-Chain Bidding via Nitrolite: Bidders submit signed messages representing their bid amounts using the Nitrolite SDK. These are processed off-chain and updated locally in real-time.

Trustless Finalization: Once the timer expires, the seller submits the highest signed bid (from their off-chain state) to the on-chain smart contract. The bid includes the bidder’s address, bid amount, and a signature.

State Channel Design: All interactions follow the ERC-7824 standard, ensuring secure, replay-protected state updates. The implementation uses Yellow’s TypeScript SDK for message formatting, signing, and channel handling.

Why this matters: Traditional blockchain auctions are slow, gas-intensive, and vulnerable to bots. FlashBid eliminates these problems by moving the high-frequency logic off-chain while preserving trust. It uses ERC-7824 for portable state channel messaging and keeps final settlement on-chain and verifiable.

What’s built: A functional frontend (React + Wagmi) Integrated Nitrolite SDK for off-chain state management

Future use cases: NFT marketplaces with real-time auctions Private token sales with gasless bidding DAO auctions for treasury assets Game marketplaces (e.g., weapons or skins)

This project targets Yellow’s bounty exclusively. It demonstrates a practical use of ERC-7824 state channels via the Nitrolite SDK. All code is open-source.

Frontend: The UI was built with React and TypeScript using the Ethers library for wallet connection. The app displays live auction state, lets users submit bids, and handles the finalization flow. All bids are entered client-side and signed by the user using their wallet.

State Channels (Nitrolite): The core of the project uses the @erc7824/nitrolite SDK to manage off-chain state updates for each bid. Each signed bid message contains the bid amount, a nonce, and the bidder’s address. These are signed and passed between participants to simulate the channel-based logic.