AirdropDistributor (VRF Winner Selection)

Overview

AirdropDistributor is a recurring airdrop contract. Addresses register themselves into a pool, and on a fixed schedule AutoLoop uses ECVRF to pick winnersPerDraw winners via a partial Fisher-Yates shuffle. Each winner receives prizePerWinner ETH minus a protocol fee.

Why AutoLoop + VRF Are Structurally Required

The trigger holder knows who wins before the call. With a deterministic or predictable RNG, whoever submits the draw transaction can compute all possible winners in advance and time the call to a favorable block. AutoLoop's ECVRF provides verifiable randomness with on-chain proof verification — the winner is only known after the transaction is mined.

Mechanics

• Register/Deregister: any address calls register() or deregister() to enter/leave the pool
• shouldProgressLoop: returns true when pool size ≥ winnersPerDraw and drawInterval has elapsed
• Winner selection: Fisher-Yates partial shuffle using VRF randomness picks winnersPerDraw non-repeating addresses
• Prize distribution: (totalPrize * PROTOCOL_FEE_BPS) / 10000 goes to protocol; remainder split equally among winners
• Pool preservation: the full pool remains registered for the next draw — winners aren't removed

Revenue Model

• 2% protocol fee on total prize per draw
• AutoLoop gas fee per draw tick

Deploy

forge create src/agents/AirdropDistributor.sol:AirdropDistributor \
  --constructor-args 604800 3 100000000000000000 \
  --rpc-url $RPC_URL --private-key $PRIVATE_KEY --broadcast

Args: drawInterval (seconds), winnersPerDraw, prizePerWinner (wei). Fund the contract with at least winnersPerDraw × prizePerWinner ETH before draws begin.

Dashboard

View AirdropDistributor on the AutoLoop Dashboard.