Integrate as a Router or Aggregator

Context

This guide is for aggregators, routers, solvers, and quote APIs sourcing liquidity from DualPool pools. The headline: execution is a completely ordinary v4 swap; only quoting is different. A DualPool holds zero persistent v4 liquidity between swaps, so onchain pool depth is not a routing signal: getSlot0 shows a price, but getLiquidity is ~0. Capacity is discovered through the hook's view functions.

Detect a DualPool

Discover hooks through the AllowlistedFactory (deployments): index its Deployed events, or enumerate allDeployments onchain. Verify provenance in either direction with factory.isFromFactory(hook) or hook.factory(); a hook the factory vouches for is a bit-exact build of the audited bytecode. For each hook, its pools are the PoolCreated events it emits (equivalently, the PoolManager's Initialize events filtered on the hook address).

Once you have a candidate hook, confirm it implements the ALF view interface (IALFHook.sol) via ERC-165:

bool isAlf = IERC165(address(key.hooks)).supportsInterface(type(IALFHook).interfaceId);

A hook that passes carries the uniform IALFHook quote surface below, so you do not need to distinguish DualPool from other ALF strategies. DualPool-specific signals, if you want them, include livePools(poolId) and getDistribution(poolId).

The Quote Surface

All methods are view, intended to be called via staticcall:

Conventions:

• amountSpecified follows v4's convention: negative for exact input, positive for exact output. Exact-input quotes return the expected output; exact-output quotes return the required input.
• zeroForOne = true swaps currency0 -> currency1.
• hookData is ignored entirely; pass empty bytes. There are no attestations, signed curves, or per-swap discounts.
• The quote already composes the static LP fee (key.fee) with any v4 protocol fee. Do not re-apply either.

Size Fills Against Effective Liquidity

This is the one accounting subtlety that affects fill sizing:

• getReserves is what LPs own: vault.convertToAssets(shares) + claims + tracked ERC-20
• getEffectiveLiquidity is what the hook can withdraw and deploy this block: vault.previewRedeem(shares) + claims + tracked ERC-20

When the pool's ERC-4626 vault is paused, capped, or utilization-constrained, effective liquidity drops below reserves. The JIT cycle and quote path both size against effective liquidity, so plan fills against getEffectiveLiquidity, not getReserves. swapToPrice already does this internally, so prefer it for split planning.

Quote Fidelity

getIndicativeQuote and swapToPrice are a compact, single-step simulation: they sum the liquidity of the distribution buckets in range at the current tick and run one SwapMath.computeSwapStep against that constant liquidity. Implications:

• Accurate for swaps that stay within the current in-range bucket set, the common small and medium swap near the peg
• No tick-walking across bucket boundaries: a large swap that crosses into or out of bucket ranges sees liquidity change mid-swap that the single-step quote does not capture
• The output leg is capped at the effective output reserve, so a quote can never exceed what the pool can deliver

Recommendations:

1. Use getIndicativeQuote for ranking
2. Use swapToPrice with a real sqrtPriceLimitX96 for split planning and tighter fills, so the simulation is bounded the same way execution will be
3. Track persistent quote-vs-fill divergence per pool and feed it into your routing reputation model; the design expects routers to deprioritize on sustained divergence

Failure Modes

Execution

Nothing here is DualPool-specific: swap as you would against any v4 pool, via the PoolManager or the Universal Router, and enforce your own slippage. See Swap Against a DualPool.

Integration Checklist

• Confirm the hook via supportsInterface(type(IALFHook).interfaceId)
• Quote through getIndicativeQuote / swapToPrice, never pool liquidity
• Pass hookData = ""
• Read the fee from key.fee (static; never the dynamic-fee flag)
• Size fills against getEffectiveLiquidity, not getReserves
• Cap quote staticcall gas at maxGas()
• Treat a 0 quote as "skip"; pre-filter with livePools(poolId) for direct routing
• Enforce your own slippage on execution
• Track quote fidelity per pool

Where to Go Next

• See where the numbers behind getReserves and getEffectiveLiquidity come from
• Swap against a DualPool