web3
Boostr
LiveOn-chain engagement marketplace for Farcaster.
Problem
Farcaster creators wanted ways to amplify their casts, but the only options were bots or trust-based services with no payment guarantees. There was no trustless way for real users to monetise their reactions, or for buyers to pay only for engagement that actually landed.
Approach
Built Boostr, a Farcaster Mini App that connects advertisers with Farcaster users through a two-sided engagement marketplace. Buyers fund campaigns using USDC, with support for one-click batched transactions (EIP-5792) and a sequential approve-and-pay fallback for wallet compatibility. Campaign funds are managed by a UUPS-upgradeable smart contract deployed on Arbitrum. Users can delegate a Farcaster signer once and earn USDC by completing engagement tasks such as likes, recasts, and quote casts, which are executed automatically by the backend on their behalf. The platform uses EIP-712 signed cumulative claims for earnings and refunds, preventing replay attacks while allowing the payout signing key to be rotated securely on-chain.
Outcome
Live on Arbitrum mainnet, open inside Farcaster as @boostr. Real USDC settlement on every purchase, with sub-second push notifications to amplifiers the moment their reactions earn.