RouletteSwap🎰

🎰 Introducing RouletteSwap — a Uniswap v4 Hook where every swap is a coin flip you opt into. Safe: flat 30 bps Risky: 5/6 of 5 bps · 1/6 of 155 bps Expected fee identical. LP economics neutral. Live on @XLayerOfficial testnet 🧵 #BuildX

🥉 3rd place @ @XLayerOfficial × @Uniswap × @flapdotsh "Hook the Future" 🙏 Huge thanks to the X Layer team for a well-run hackathon. What we shipped: • novel per-swap fee distribution primitive • 8/8 Foundry tests + 600-trial statistical invariant • live on X Layer testnet

24 Risky swaps on @RouletteSwap "Beat the House" mode. bust 2 · survive 22 (RNG was kind today) paid: 420 bps if all Safe: 720 bps → saved 300 bps LP economics unchanged. variance is a feature, not a bug. @XLayerOfficial #BuildX

why 5/6 odds, not 9/10 or 99/100? EV must equal 30 bps → bust fee is forced: 1/6 → 155 bps (5x baseline) 1/10 → 255 bps (8.5x) 1/100 → 2,500+ (degen-only) 5/6 = d6 intuition · cheap to compute · real variance · survivable bust @XLayerOfficial #BuildX

how to prove a "5/6 chance of 5 bps · 1/6 of 155" hook is actually EV-neutral? let Foundry do it. 600 trials. mean fee within ±20% of 3000 pips. bust frequency within ±35% of 1/6. if either bound trips, the contract ships broken. 8/8 tests green. @XLayerOfficial #BuildX

every v4 fee hook asks "what's the fee?" nobody asks "what's the fee DISTRIBUTION?" RouletteSwap: uint24 lpFee = roll() == BUST ? 15_500 : 500; 5 bps survive · 155 bust · 1/6 odds · LP-EV-neutral @XLayerOfficial #BuildX

@XLayerOfficial @Uniswap @flapdotsh The math: E[Safe] = 30 bps E[Risky] = (5/6)·5 + (1/6)·155 = 30 bps Identical EV — verified by a 600-trial Foundry invariant. LPs see zero EV impact. Strict Pareto improvement on AMM fee design. Hook: oklink.com/xlayer-test/ad…

@XLayerOfficial Built for the @XLayerOfficial × @Uniswap × @flapdotsh "Hook the Future" hackathon. One contract. ~110 LOC of business logic. No oracles. No admin keys. No token. Just per-swap risk election attached to a real v4 pool. Code: github.com/gdongxi/roulet…

🎰 Introducing RouletteSwap — a Uniswap v4 Hook where every swap is a coin flip you opt into. Safe: flat 30 bps Risky: 5/6 of 5 bps · 1/6 of 155 bps Expected fee identical. LP economics neutral. Live on @XLayerOfficial testnet 🧵 #BuildX