Uniswap v4 hooks bring outside liquidity to three chains

Uniswap Labs launched Aggregator Hooks on Ethereum, Base and Robinhood Chain on October 22, bringing outside liquidity into routes on Uniswap v4 and charging protocol fees on swaps that use it. The feature is available in the Uniswap Web App and API, according to Uniswap Labs’ launch announcement.

How do the hooks connect outside liquidity?

An Aggregator Hook wraps an external liquidity source in a Uniswap v4 hook. That makes the source appear to a router as a Uniswap pool. The router pulls fresh quotes from connected sources every block, then compares them with quotes from Uniswap pools to build a route for the swap. It settles the route in one transaction, with no new approval required.

The hook works like an adapter: it gives the router a common way to see liquidity held elsewhere. Fluid, Curve and PancakeSwap are among the sources available at launch, The Block reported. Uniswap Labs says seven sources are live, covering more than 90% of DEX activity across the three chains.

Where can users access Aggregator Hooks?

Swaps on the Uniswap Web App include external sources automatically. Developers can also route trades through the Uniswap API on Ethereum mainnet, Base and Robinhood Chain. The router handles the comparison and settlement, so users do not need to select or approve each outside venue separately.

The launch extends v4’s routing across pools operated outside Uniswap. A swap may draw on Uniswap liquidity, an external source, or a route combining both, depending on the quotes the router sees. Uniswap says the complete route settles as a single transaction.

What happens to fees from outside liquidity?

Swaps routed through external sources pay Uniswap protocol fees, which contribute to UNI burns, according to the launch announcement. That means the new routes also bring fee-generating activity into the protocol when a trade uses outside liquidity.

Uniswap says more than $4.5 trillion has been swapped through its protocol. The company’s stated rationale for Aggregator Hooks is that liquidity can form beyond Uniswap’s own pools, and v4 can now include those sources in its routes. The launch announcement says more chains and sources are planned, without giving a timetable.

Sources and documents

• Uniswap Labs’ launch announcement — blog.uniswap.org
• The Block reported — theblock.co