Microbid

Microbid is a platform for provably fair, fully onchain, penny auctions. The platform allows for auctioning real world assets as well as digital assets, like NFTs.

Users must create a Proof of Personhood with Worldcoin World ID in order to bid on auctions. Each bid costs $0.10 and can be bought with USDC. When a bid is placed, the price of the auction increases by $0.01 and if placed within the last ~20 seconds more time is added to the auction. When the timer runs out, the last bidder can then purchase the item at the final cost.

The main issue with existing penny auction sites is the lack of credibility and transparency. In Microbid you can be sure that ever bid placed is by a real person, and all transactions are onchain and independently verifiable.

This project uses multiple smart contracts deployed to Base L2. World ID is used to create a Proof of Personhood. Once the proof is verified onchain, an attestation is created on the Ethereum Attestation Service. This allows for quick verified bidding without the need to create further proofs. Alchemy Account Kit is used extensively to enable Smart Accounts, requiring only an email address to sign up. All transactions performed by the embedded accounts are sponsored, allowing for signless bidding and usage.