Aggregator Hooks make liquidity from external decentralized exchanges appear as native Uniswap v4 pools to trading routers

From the articleDeFi Giant Uniswap Taps 7 Rival Liquidity Sources to Burn UNI TokensAlso in Uniswap's aggregator hooks go live on Ethereum, Base and Robinhood Chain, Uniswap Turns v4 Into an Aggregator, Sending Fees From Outside Liquidity to UNI Burn - Unchained, Uniswap v4 Is Now an Aggregator, Uniswap adds seven trading sources as 0x disputes its protection from malicious hooks