Liquidswap fees must be separated from gas and price impact

Cost entries for a like-for-like comparison

A like-for-like comparison uses the same transaction shape, fixed amount, asset identifiers, contract family and observation time. It also separates charges from exchange-rate effects and execution limits. Adding every visible field together would count some items twice because fee allocations divide an existing charge rather than create another one.

The trader pays the pool fee through the swap calculation. Liquidity providers and the treasury receive configured portions, so neither allocation belongs beside the full fee as another trader charge. V1 narrows provider earnings to liquidity in bins used by the swap.

Price impact also reduces economic value without producing a separate transfer labeled as a fee. Slippage tolerance is different again: it defines acceptable movement between quote and execution. A borrowing rate, bridge charge or exchange withdrawal fee belongs outside the Liquidswap pool comparison unless another service introduced it.

What turns a quoted output into a final amount?

For an exact-input swap, the pool state at execution decides the final token output, provided it satisfies the transaction’s encoded limit. A quote estimates the output from the state read before submission. It does not reserve liquidity or freeze V1 fee variables while the wallet request remains unsigned or pending.

Amounts to keep separate

Expected output

The expected output is the estimate returned for the specified input under the selected pool’s reserves, price bins and fee parameters. It normally reflects the pool calculation, including its swap fee. It does not absorb the separate Aptos gas charge because gas uses the network’s accounting rather than the output-token calculation.

Minimum accepted output

The minimum output is the lowest result the signed transaction authorizes. Liquidswap routers use this value as a slippage check and abort the swap when execution would return less. The distance between expected and minimum output is therefore tolerance for state movement, not an amount automatically paid to another party.

An exact-output transaction reverses the constraint. The desired output stays fixed while a maximum input caps what the router may spend, and any unused input returns to the account. Comparing exact-input with exact-output activity requires matching the accepted constraint as well as the displayed amounts.

V0.5 and V1 use different fee logic

The selected contract family determines which fee model applies. Treating every Liquidswap pool as one fee tier can produce a false comparison even when the input and output asset labels look identical.

V0.5 pool configuration

V0.5 supports separate stable and uncorrelated curves. Its pool fees are configurable, as is the division between liquidity providers and the treasury. The applicable values must come from the selected pool’s configuration rather than a remembered default. That preserves differences between pools without presenting an old setting as permanent.

V1 dynamic calculation

Liquidswap V1 calculates its base fee by multiplying the pool’s base factor by its bin step.

The total V1 swap fee adds a variable component to that base. A volatility accumulator responds to factors including bins crossed and elapsed time between transactions. The parameter set also imposes a maximum fee. Since these inputs belong to a particular pool, another bin-step pool for the same pair can produce a different cost structure.

Liquidity providers earn from bins the swap actually uses, while a configured protocol portion goes to the treasury. Provider fees accumulate with the position and can be collected when liquidity is withdrawn. The treasury component remains a configured allocation rather than another volatility-driven charge.

Aptos gas belongs beside the swap quote

Every Aptos transaction carries a gas unit price specified in the network’s native token. The settled network charge follows actual gas use and the gas unit price, while the maximum gas amount is an execution cap rather than the final bill. Record gas in APT separately from token output and note the transaction’s fee payer. Converting both into one currency requires a clearly chosen market price and timestamp, which are comparison inputs rather than Liquidswap protocol facts.

Why can two similar swaps settle at different costs?

Two swaps diverge when the pool, fee parameters, liquidity state, input size or network gas changes. Matching token symbols and a similar displayed amount do not establish a like-for-like comparison.

Pool liquidity can move between the quote and execution. In V1, crossing a different set of bins can also affect the variable fee calculation. The later transaction may therefore receive a different output even when its sender chooses the same nominal input and slippage setting.

Trade size changes price impact because the swap consumes available liquidity along its pricing path. This effect belongs in the realized exchange rate, not in the fee column. A benchmark price can reveal the difference, but both observations need the same time basis and compatible asset units.

Asset symbols alone cannot identify an Aptos asset or Liquidswap pool. A sound record keeps the full asset types, contract version and pool identity. For V1, it also keeps the bin step. That prevents a comparison from joining transactions governed by different contracts or fee settings.

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A reproducible quote-to-settlement record

A reproducible comparison pairs the pre-submission quote with the confirmed transaction rather than relying on screenshots taken at unrelated times. For an exact-input swap, the quote side needs the exact input, expected output, minimum output, asset identities, pool identity, contract version and observation time. For an exact-output swap, record the desired output and maximum input instead.

The settlement side needs transaction status, actual token balance changes, gas used and gas unit price. For an exact-input record, compare the output received with the expected output first. For an exact-output record, compare the actual input spent with the expected input. Keep the gas record separate until both values can be converted with the same valuation method and timestamp.

For an exact-input swap, quote deviation can be expressed as expected output minus received output, divided by expected output. Effective exchange cost needs a separate benchmark and identical decimal handling. Neither formula should add the treasury and provider portions after the full pool fee, since those portions divide the same charge.

This record shows the difference between the quote and pool execution, whether the result met the acceptance boundary and the Aptos gas charge. It also keeps unrelated bridge, borrowing and exchange charges from being mislabeled as Liquidswap fees.