feat: handle app fees #1677

ashwinrava · 2025-07-23T18:37:00Z

Add 2 query params appFeePercent and appFeeRecipient
Add function calculateAppFee which returns the the fee amount and action to be used by the multicall handler
Use new function in cross-swap-service for different swap scenarios to apply the app fee
Create final JSON with USD amounts for each fee and converted base unit values

Tested and documented scenario outputs here: https://docs.google.com/document/d/1YawQNsNY-7I8OXqLImtveve6Y306WTD-cJYmeme7lA8

Closes ACX-4225

Closes ACX-4224

vercel · 2025-07-23T18:37:05Z

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
app-frontend-v3	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Aug 1, 2025 5:14pm
sepolia-frontend-v3	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Aug 1, 2025 5:14pm

api/swap/_utils.ts

dohaki

I think the overall approach makes sense to me! There are still some open questions on my side that came up while reviewing. Some might be more of a product question but would be interesting to get your view on it.

api/_dexes/utils.ts

api/_dexes/cross-swap-service.ts

dohaki · 2025-07-25T07:47:57Z

api/_dexes/cross-swap-service.ts

+      crossSwap.type === AMOUNT_TYPE.EXACT_INPUT
+        ? destinationSwapQuote.minAmountOut


This should never be the case because we are inside getCrossSwapQuotesForOutputB2A which only handles output-amount based flows

dohaki · 2025-07-25T07:51:21Z

api/_dexes/cross-swap-service.ts

@@ -1073,6 +1136,7 @@ export async function getCrossSwapQuotesForOutputByRouteA2A(
          prioritizedDestinationStrategy.result.bridgeableOutputToken,
        routerAddress:
          prioritizedDestinationStrategy.result.destinationRouter.address,
+        destinationOutputAmount: crossSwap.amount,


We are inside getCrossSwapQuotesForExactInputByRouteA2A so this needs to be

Suggested change

destinationOutputAmount: crossSwap.amount,

destinationOutputAmount: prioritizedDestinationStrategy.indicativeDestinationSwapQuote.minAmountOut,

appFee is missing here?

Discussed offline about appFee - We only need to include it in the final bridgeQuote.message override.

dohaki · 2025-07-25T07:52:25Z

api/_dexes/cross-swap-service.ts

@@ -1159,6 +1223,7 @@ export async function getCrossSwapQuotesForOutputByRouteA2A(
              prioritizedDestinationStrategy.indicativeDestinationSwapQuote,
            bridgeableOutputToken,
            routerAddress: destinationRouter.address,
+            destinationOutputAmount: crossSwap.amount,


We are inside getCrossSwapQuotesForExactInputByRouteA2A so this needs to be

Suggested change

destinationOutputAmount: crossSwap.amount,

destinationOutputAmount: prioritizedDestinationStrategy.indicativeDestinationSwapQuote.minAmountOut,

appFee is missing here?

api/_dexes/utils.ts

dohaki · 2025-07-25T08:03:53Z

api/swap/_utils.ts

+  // Get USD prices for all tokens and native tokens
+  const [
+    inputTokenPriceUsd,
+    outputTokenPriceUsd,
+    originNativePriceUsd,
+    destinationNativePriceUsd,
+  ] = await Promise.all([


From a perf perspective it would be nice if we can pass all prices in as args. So that we do a Promise.all from within ./approval/_service.ts alongside one of the async methods so improve latency

dohaki · 2025-07-25T08:07:43Z

api/swap/_utils.ts

+      utils.formatUnits(bridgeFees.totalRelayFee.total, outputToken.decimals)
+    ) * outputTokenPriceUsd;
+
+  const totalFeeUsd = relayerTotalUsd + appFeeUsd;


We also need to price in the "swap impact". So basically

swapImpactUsd = inputAmountUsd - outputAmountUsd - relayerTotalUsd - appFeeUsd`

dohaki · 2025-07-25T08:09:35Z

api/swap/_utils.ts

+      pct: getNormalizedPercentage(
+        originGasUsd,
+        params.inputAmount,
+        inputToken.decimals,
+        inputTokenPriceUsd
+      ),


If I think about this one, the pct doesn't really make sense to me 🤔 Because the origin gas is not priced into the total fees (at least for gasful flows)

dohaki · 2025-07-25T08:10:54Z

api/swap/_utils.ts

+    destinationGas: {
+      amount: destinationGas.total,
+      amountUsd: destinationGasUsd,
+      pct: destinationGas.pct,
+    },
+    relayerCapital: {
+      amount: relayerCapital.total,
+      amountUsd: relayerCapitalUsd,
+      pct: relayerCapital.pct,
+    },
+    relayerTotal: {
+      amount: bridgeFees.totalRelayFee.total,
+      amountUsd: relayerTotalUsd,
+      pct: bridgeFees.totalRelayFee.pct,


I don't think we can directly reuse the pct values here from the bridge quote. Because in case of origin and/or destination swaps, the swap impact is not priced into the total

Yeah I removed pct from these for now. I am a little unclear what the percentage is meant to reflect. Is it always w.r.t input amount?

dohaki

Nice this looks awesome! I could also send some tx with app fees 💪 There are still some open questions I left on the response format of the fees. We can sync on that offline as well

dohaki · 2025-07-31T05:35:14Z

api/swap/_utils.ts

+      amountUsd: totalFeeUsd,
+      pct: totalFeeUsd / inputAmountUsd,
+    },
+    originGas: {


In the PRD it was specified to also include the respective token information for the components. We can also add this as a fast-follow if you think the required work is a bit too much

So originGas would include the respective gas tokens of the chain. relayerCapital, destinationGas and relayerTotal in the bridged output token? And app in the output token

dohaki · 2025-07-31T05:37:59Z

api/swap/_utils.ts

+
+  const bridgeFees = bridgeQuote.suggestedFees;
+  const relayerCapital = bridgeFees.relayerCapitalFee;
+  const destinationGas = bridgeFees.relayerGasFee;


I think we are missing lpFee

dohaki · 2025-07-31T05:39:03Z

api/swap/_utils.ts

+  return {
+    total: {
+      amount: totalFeeUsd,
+      amountUsd: totalFeeUsd,


We should probably return them as strings? 🤔 To avoid scientific notation but not sure what the best practice is here

dohaki · 2025-07-31T05:40:09Z

api/swap/_utils.ts

+
+  return {
+    total: {
+      amount: totalFeeUsd,


Hmm this should probably be in the inputToken?

melisaguevara · 2025-07-31T17:18:56Z

api/_dexes/cross-swap-service.ts

+  if (appFee.feeAmount.gt(0)) {
+    bridgeQuote.message = buildExactInputBridgeTokenMessage(
+      crossSwap,
+      bridgeQuote.outputAmount,
+      appFee
+    );
+  }


Isn't this needed even if appFee.feeAmount is 0? So that the output is updated from crossSwap.amount to bridgeQuote.amount?

Yeah good point. Will amend.

api/_dexes/cross-swap-service.ts

linear · 2025-08-01T17:00:00Z

ACX-4225 Handle `appFees` provided by caller

ACX-4224 Add `fees` field to `/swap`response

vercel bot deployed to Preview – sepolia-frontend-v3 July 23, 2025 18:40 View deployment

vercel bot deployed to Preview – app-frontend-v3 July 23, 2025 18:51 View deployment

melisaguevara reviewed Jul 23, 2025

View reviewed changes

api/swap/_utils.ts Show resolved Hide resolved

ashwinrava force-pushed the app-fee-destination-swap branch from 41229ef to 4f0cf1f Compare July 23, 2025 19:04

vercel bot deployed to Preview – sepolia-frontend-v3 July 23, 2025 19:15 View deployment

vercel bot deployed to Preview – app-frontend-v3 July 23, 2025 19:24 View deployment

ashwinrava force-pushed the app-fee-destination-swap branch from 4f0cf1f to bd3d6ef Compare July 23, 2025 19:48

vercel bot deployed to Preview – sepolia-frontend-v3 July 23, 2025 19:58 View deployment

vercel bot deployed to Preview – app-frontend-v3 July 23, 2025 20:08 View deployment

vercel bot deployed to Preview – app-frontend-v3 July 24, 2025 20:44 View deployment

vercel bot deployed to Preview – sepolia-frontend-v3 July 24, 2025 20:54 View deployment

dohaki reviewed Jul 25, 2025

View reviewed changes

vercel bot deployed to Preview – sepolia-frontend-v3 July 25, 2025 19:19 View deployment

vercel bot deployed to Preview – app-frontend-v3 July 25, 2025 19:29 View deployment

vercel bot deployed to Preview – sepolia-frontend-v3 July 25, 2025 20:06 View deployment

vercel bot deployed to Preview – app-frontend-v3 July 25, 2025 20:16 View deployment

ashwinrava force-pushed the app-fee-destination-swap branch from 41c8881 to c6ea809 Compare July 29, 2025 00:54

vercel bot had a problem deploying to Preview – sepolia-frontend-v3 July 29, 2025 00:55 Failure

vercel bot deployed to Preview – app-frontend-v3 July 29, 2025 01:05 View deployment

ashwinrava changed the title ~~feat: handle app fees for destination swap~~ feat: handle app fees Jul 29, 2025

melisaguevara force-pushed the EPIC-swap-actions branch from 454a4f6 to c9327be Compare July 29, 2025 18:21

ashwinrava force-pushed the app-fee-destination-swap branch from c6ea809 to a1d9510 Compare July 29, 2025 19:52

vercel bot deployed to Preview – app-frontend-v3 July 29, 2025 20:03 View deployment

vercel bot had a problem deploying to Preview – sepolia-frontend-v3 July 29, 2025 20:03 Failure

ashwinrava force-pushed the app-fee-destination-swap branch 2 times, most recently from cf87020 to af01b7f Compare July 30, 2025 22:43

vercel bot deployed to Preview – app-frontend-v3 July 30, 2025 22:55 View deployment

vercel bot deployed to Preview – sepolia-frontend-v3 July 30, 2025 23:06 View deployment

ashwinrava force-pushed the app-fee-destination-swap branch from af01b7f to 02a8289 Compare July 30, 2025 23:59

vercel bot deployed to Preview – sepolia-frontend-v3 July 31, 2025 00:09 View deployment

vercel bot deployed to Preview – app-frontend-v3 July 31, 2025 00:20 View deployment

ashwinrava force-pushed the app-fee-destination-swap branch from 02a8289 to 649934c Compare July 31, 2025 01:25

vercel bot deployed to Preview – app-frontend-v3 July 31, 2025 01:36 View deployment

vercel bot deployed to Preview – sepolia-frontend-v3 July 31, 2025 01:46 View deployment

dohaki reviewed Jul 31, 2025

View reviewed changes

melisaguevara reviewed Jul 31, 2025

View reviewed changes

api/_dexes/cross-swap-service.ts Show resolved Hide resolved

ashwinrava force-pushed the app-fee-destination-swap branch from 649934c to 96236f4 Compare August 1, 2025 16:03

vercel bot deployed to Preview – sepolia-frontend-v3 August 1, 2025 16:13 View deployment

vercel bot deployed to Preview – app-frontend-v3 August 1, 2025 16:24 View deployment

Handle app fees

d705281

ashwinrava force-pushed the app-fee-destination-swap branch from 96236f4 to d705281 Compare August 1, 2025 16:52

ashwinrava changed the base branch from EPIC-swap-actions to master August 1, 2025 16:53

ashwinrava marked this pull request as ready for review August 1, 2025 17:00

ashwinrava requested review from mrice32, nicholaspai, james-a-morris, pxrl and amateima as code owners August 1, 2025 17:00

vercel bot deployed to Preview – sepolia-frontend-v3 August 1, 2025 17:03 View deployment

vercel bot deployed to Preview – app-frontend-v3 August 1, 2025 17:14 View deployment

		crossSwap.type === AMOUNT_TYPE.EXACT_INPUT
		? destinationSwapQuote.minAmountOut

	destinationOutputAmount: crossSwap.amount,
	destinationOutputAmount: prioritizedDestinationStrategy.indicativeDestinationSwapQuote.minAmountOut,

feat: handle app fees #1677

Are you sure you want to change the base?

feat: handle app fees #1677

Conversation

ashwinrava commented Jul 23, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

vercel bot commented Jul 23, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Uh oh!

dohaki left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

dohaki left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

melisaguevara Jul 31, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

linear bot commented Aug 1, 2025

Uh oh!

Uh oh!

ashwinrava commented Jul 23, 2025 •

edited

Loading

vercel bot commented Jul 23, 2025 •

edited

Loading

melisaguevara Jul 31, 2025 •

edited

Loading