Add STABLECOIN_PAYOUT_FIXED_FEE_CENTS to stablecoinFundingAmount (dubinc#3716)

Author: steven-tey

apps/web/app/(ee)/api/cron/payouts/charge-succeeded/route.ts

@@ -1,5 +1,8 @@
 import { handleAndReturnErrorResponse } from "@/lib/api/errors";
-import { MIN_WITHDRAWAL_AMOUNT_CENTS } from "@/lib/constants/payouts";
+import {
+  MIN_WITHDRAWAL_AMOUNT_CENTS,
+  STABLECOIN_PAYOUT_FIXED_FEE_CENTS,
+} from "@/lib/constants/payouts";
 import { verifyQstashSignature } from "@/lib/cron/verify-qstash";
 import { fundFinancialAccount } from "@/lib/stripe/fund-financial-account";
 import { prisma } from "@dub/prisma";
@@ -66,8 +69,9 @@ export async function POST(req: Request) {
     `;
 
     // Fund the total stablecoin payout amount for this invoice
-    const { _sum } = await prisma.payout.aggregate({
+    const { _sum, _count } = await prisma.payout.aggregate({
       _sum: { amount: true },
+      _count: { id: true },
       where: {
         invoiceId: invoice.id,
         method: "stablecoin",
@@ -81,7 +85,10 @@ export async function POST(req: Request) {
     });
 
     let skipStablecoinPayouts = false;
-    const stablecoinFundingAmount = _sum.amount ?? 0;
+    // we need to add the STABLECOIN_PAYOUT_FIXED_FEE_CENTS for each payout to the total funding amount
+    // to make sure that `createStablecoinPayout` later has enough funds to cover Stripe's fees
+    const stablecoinFundingAmount =
+      (_sum.amount ?? 0) + _count.id * STABLECOIN_PAYOUT_FIXED_FEE_CENTS;
 
     // Send money to Financial Account to handle stablecoin payouts
     if (stablecoinFundingAmount > 0) {

apps/web/lib/constants/payouts.ts

@@ -10,6 +10,7 @@ export const ELIGIBLE_PAYOUTS_MAX_PAGE_SIZE = 500;
 export const CUTOFF_PERIOD_MAX_PAYOUTS = 1000;
 
 export const STABLECOIN_PAYOUT_FEE_RATE = 0.005; // 0.5%
+export const STABLECOIN_PAYOUT_FIXED_FEE_CENTS = 50; // $0.50
 export const FAST_ACH_FEE_CENTS = 2500; // $25
 export const PAYOUT_FAILURE_FEE_CENTS = 1000; // 10 USD
 export const FOREX_MARKUP_RATE = 0.005; // 0.5%