Circle

Auto-Replenishing Cross-Chain USDC Pools

• After a swap, this hook checks if USDC reserves in a Uniswap v4 pool have dropped below a threshold. If so, it triggers a CCTP v2 bridge transfer to replenish liquidity from a Circle Wallet on another chain.
• Keeps USDC liquidity deep and responsive, especially for high-throughput cross-chain DeFi protocols. Ideal for maintaining minimum liquidity guarantees in dollar-backed pools.

Pay-Per-Swap with USDC Using Circle Paymaster

• This hook enables users to pay for gas in USDC during swaps, making Uniswap more accessible to users who don't hold ETH or other native tokens. It integrates with Circle Paymaster to automatically deduct gas fees in USDC from the user's wallet.
• Enables truly gasless UX for USDC holders, useful in consumer apps or fiat-like trading platforms.

Streaming USDC Rewards for Liquidity Providers

• Implements a liquidity mining mechanism using afterAddLiquidity and afterRemoveLiquidity to track time-weighted LP participation.Rewards are distributed in USDC over time from a Circle Wallet vault, encouraging sustained liquidity provision.
• Supports more sustainable yield farming than emission-based token rewards.

Real-Time FX Swap Pools Using CCTP

• Enables on-demand FX swaps between USDC and other stablecoins across chains by triggering a CCTP v2 transfer in beforeSwap. Users can perform cross-chain stablecoin swaps (e.g., USDC ↔ EURC) with real-time settlement into a Uniswap pool.
• Ideal for cross-border payments, decentralized neobanks, and global payroll platforms.

Compliance-Aware Swap Limits Using Smart Wallets

• Adds a compliance layer with Compliance Engine to beforeSwap, allowing only verified or smart account users to interact with USDC pools. Optionally enforces spend limits, ensuring that liquidity is accessible within regulatory constraints.
• Can integrate World ID or programmable identity with Circle Wallets.