feat(swap): default the "You receive" token to USDC

@shared/api/internal.ts

@@ -1178,11 +1178,16 @@ export const getAssetIcons = async ({
   networkDetails,
   assetsListsData,
   cachedIcons,
+  additionalAssetIds,
 }: {
   balances: Balances;
   networkDetails?: NetworkDetails;
   assetsListsData?: AssetListResponse[];
   cachedIcons: Record<string, string | null>;
+  // Canonicals to resolve alongside the held balances, even when the account
+  // doesn't hold them (e.g. the swap flow's default destination). Mirrors
+  // getTokenPrices' additionalAssetIds.
+  additionalAssetIds?: string[];
 }) => {
   const assetIcons = {} as { [code: string]: string | null };
   const skipLookup = !assetsListsData || !networkDetails;
@@ -1242,6 +1247,39 @@ export const getAssetIcons = async ({
     }
   }
 
+  // Unheld extras run the same cache -> token lists -> issuer-toml chain as
+  // the held balances above (toml via the shared domainsToFetch batch below).
+  for (const canonical of additionalAssetIds || []) {
+    const [code, key] = canonical.split(":");
+    if (!key || canonical in assetIcons) {
+      // native (no issuer segment) or already covered by a held balance
+      continue;
+    }
+
+    const cachedIcon = cachedIcons[canonical];
+    if (cachedIcon) {
+      assetIcons[canonical] = cachedIcon;
+      continue;
+    }
+    if (cachedIcon === null || skipLookup) {
+      continue;
+    }
+
+    const tokenListIcon = await getIconFromTokenLists({
+      issuerId: isContractId(key) ? undefined : key,
+      contractId: isContractId(key) ? key : undefined,
+      code,
+      assetsListsData,
+    });
+    if (tokenListIcon.icon) {
+      assetIcons[canonical] = tokenListIcon.icon;
+    } else if (!isContractId(key)) {
+      domainsToFetch.push({ key, code });
+    } else {
+      assetIcons[canonical] = null;
+    }
+  }
+
   if (domainsToFetch.length > 0 && networkDetails) {
     const assetDomains = await getAssetDomains({
       assetIssuerDomainsToFetch: domainsToFetch.map(({ key }) => key),

@shared/constants/stellar.ts

@@ -70,6 +70,15 @@ export const DEFAULT_NETWORKS: Array<NetworkDetails> = [
   TESTNET_NETWORK_DETAILS,
 ];
 
+// Default swap destination ("You receive") per network. Only networks listed
+// here get a default; on custom networks the picker starts empty.
+export const DEFAULT_SWAP_DEST_CANONICAL: Partial<Record<NETWORKS, string>> = {
+  [NETWORKS.PUBLIC]:
+    "USDC:GA5ZSEJYB37JRC5AVCIA5MOP4RHTM335X2KGX3IHOJAPP5RE34K4KZVN",
+  [NETWORKS.TESTNET]:
+    "USDC:GBBD47IF6LWK7P7MDEVSCWR7DPUWV3NY3DTQEVFL4NAT4AQH3ZLLFLA5",
+};
+
 export const BASE_RESERVE = 0.5 as const;
 export const BASE_RESERVE_MIN_COUNT = 2 as const;
 

extension/src/helpers/hooks/useGetAssetDomainsWithBalances.ts

@@ -37,6 +37,7 @@ export type AssetDomains = NeedsReRoute | ResolvedAssetDomains;
 export function useGetAssetDomainsWithBalances(getBalancesOptions: {
   showHidden: boolean;
   includeIcons: boolean;
+  additionalIconAssetIds?: string[];
 }) {
   const reduxDispatch = useDispatch<AppDispatch>();
   const isSwap = useIsSwap();

extension/src/helpers/hooks/useGetBalances.tsx

@@ -39,20 +39,28 @@ const formatBalances = async ({
   balances: NonNullable<BalanceMap>;
   showHidden: boolean;
 }) => {
+  const unfilteredBalances = sortBalances(balances);
   if (!showHidden) {
     const hiddenAssets = await getHiddenAssets({
       activePublicKey: publicKey,
     });
-    return sortBalances(
-      filterHiddenBalances(balances, hiddenAssets.hiddenAssets),
-    );
-  } else {
-    return sortBalances(balances);
+    return {
+      balances: sortBalances(
+        filterHiddenBalances(balances, hiddenAssets.hiddenAssets),
+      ),
+      unfilteredBalances,
+    };
   }
+  return { balances: unfilteredBalances, unfilteredBalances };
 };
 
 export interface AccountBalances {
   balances: AssetType[];
+  // `balances` with no visibility filtering. Hidden assets are a display
+  // preference; anything that feeds transaction construction (e.g. "does a
+  // trustline already exist?") must consult this list, or a hidden held asset
+  // reads as unheld.
+  unfilteredBalances?: AssetType[];
   isFunded: AccountBalancesInterface["isFunded"];
   subentryCount: AccountBalancesInterface["subentryCount"];
   error?: AccountBalancesInterface["error"];
@@ -62,6 +70,9 @@ export interface AccountBalances {
 function useGetBalances(options: {
   showHidden: boolean;
   includeIcons: boolean;
+  // Canonicals to resolve icons for alongside the held balances (e.g. the
+  // swap flow's default destination, which the account may not hold).
+  additionalIconAssetIds?: string[];
 }) {
   const reduxDispatch = useDispatch<AppDispatch>();
   const [state, dispatch] = useReducer(
@@ -96,15 +107,17 @@ function useGetBalances(options: {
               shouldSkipScan,
             );
 
+      const { balances, unfilteredBalances } = await formatBalances({
+        publicKey,
+        balances: accountBalances.balances as NonNullable<BalanceMap>,
+        showHidden: options.showHidden,
+      });
       const payload = {
         isFunded: accountBalances.isFunded,
         subentryCount: accountBalances.subentryCount,
         error: accountBalances.error,
-        balances: await formatBalances({
-          publicKey,
-          balances: accountBalances.balances as NonNullable<BalanceMap>,
-          showHidden: options.showHidden,
-        }),
+        balances,
+        unfilteredBalances,
       } as AccountBalances;
 
       if (options.includeIcons) {
@@ -129,6 +142,7 @@ function useGetBalances(options: {
           networkDetails,
           assetsListsData,
           cachedIcons: cachedIconsFromCache,
+          additionalAssetIds: options.additionalIconAssetIds,
         });
         payload.icons = icons;
         reduxDispatch(saveTokenLists(assetsListsData));

extension/src/popup/components/InternalTransaction/ReviewTransaction/__tests__/ReviewTx.trustlineBanner.test.tsx

@@ -76,6 +76,43 @@ describe("ReviewTx trustline banner", () => {
     ).toBeInTheDocument();
   });
 
+  it("renders the banner from the balances-derived flag when there is no pick-time snapshot (defaulted destination)", () => {
+    render(
+      <Wrapper state={{}} routes={["/"]}>
+        <ReviewTx
+          {...baseProps}
+          destinationTokenDetails={null}
+          requiresTrustline
+        />
+      </Wrapper>,
+    );
+    // Token code falls back to the destination canonical (AQUA).
+    const banner = screen.getByTestId("review-tx-trustline-banner");
+    expect(banner).toBeInTheDocument();
+    fireEvent.click(banner);
+    expect(screen.getByTestId("trustline-info-sheet")).toBeInTheDocument();
+  });
+
+  it("lets the balances-derived flag override a stale snapshot", () => {
+    render(
+      <Wrapper state={{}} routes={["/"]}>
+        <ReviewTx
+          {...baseProps}
+          destinationTokenDetails={{
+            tokenCode: "AQUA",
+            requiresTrustline: true,
+            decimals: 7,
+            issuer: "GBNZILSTVQZ4R7IKQDGHYGY2QXL5QOFJYQMXPKWRRM5PAV7Y4M67AQUA",
+          }}
+          requiresTrustline={false}
+        />
+      </Wrapper>,
+    );
+    expect(
+      screen.queryByTestId("review-tx-trustline-banner"),
+    ).not.toBeInTheDocument();
+  });
+
   it("does not render the banner when no trustline is required", () => {
     render(
       <Wrapper state={{}} routes={["/"]}>

extension/src/popup/components/InternalTransaction/ReviewTransaction/index.tsx

@@ -101,6 +101,11 @@ interface ReviewTxProps {
   // Friendly per-feature reasons from the source token scan, listed in the
   // expandable Blockaid pane alongside the transaction-scan reasons.
   sourceTokenSecurityWarnings?: BlockaidWarning[];
+  // Balances-derived "this swap adds a trustline" flag. The pick-time snapshot
+  // above is absent for defaulted/deep-linked destinations, so callers that
+  // derive the flag from holdings pass it here; when omitted, the snapshot's
+  // flag applies (legacy behavior).
+  requiresTrustline?: boolean;
 }
 
 export const ReviewTx = ({
@@ -119,6 +124,7 @@ export const ReviewTx = ({
   destinationTokenDetails,
   sourceTokenSecurityLevel,
   sourceTokenSecurityWarnings,
+  requiresTrustline: requiresTrustlineProp,
 }: ReviewTxProps) => {
   const { t } = useTranslation();
   const dispatch = useDispatch();
@@ -311,7 +317,13 @@ export const ReviewTx = ({
   const [isOnFeesPane, setIsOnFeesPane] = useState(false);
   const [isOnMemoPane, setIsOnMemoPane] = useState(false);
 
-  const requiresTrustline = !!destinationTokenDetails?.requiresTrustline;
+  const requiresTrustline =
+    requiresTrustlineProp ?? !!destinationTokenDetails?.requiresTrustline;
+  // A defaulted/deep-linked destination has no pick-time snapshot, so the
+  // banner/sheet token code falls back to the destination canonical.
+  const trustlineTokenCode =
+    destinationTokenDetails?.tokenCode ||
+    (dstAsset ? getAssetFromCanonical(dstAsset.canonical).code : "");
   const [isOnTrustlinePane, setIsOnTrustlinePane] = useState(false);
 
   // Extract contract ID for custom tokens or collectibles
@@ -470,7 +482,7 @@ export const ReviewTx = ({
         )}
         {requiresTrustline && (
           <TrustlineBanner
-            tokenCode={destinationTokenDetails!.tokenCode}
+            tokenCode={trustlineTokenCode}
             onClick={() => setIsOnTrustlinePane(true)}
           />
         )}
@@ -683,7 +695,7 @@ export const ReviewTx = ({
               modal and appear in place. */}
           {isOnTrustlinePane ? (
             <TrustlineInfoSheet
-              tokenCode={destinationTokenDetails?.tokenCode || ""}
+              tokenCode={trustlineTokenCode}
               onClose={() => setIsOnTrustlinePane(false)}
             />
           ) : isOnBlockaidSheet ? (

extension/src/popup/components/InternalTransaction/SubmitTransaction/hooks/useSubmitTxData.tsx

@@ -16,6 +16,7 @@ import { NetworkDetails } from "@shared/constants/stellar";
 import { emitMetric } from "helpers/metrics";
 import { METRIC_NAMES } from "popup/constants/metricsNames";
 import { getAssetFromCanonical, isMainnet } from "helpers/stellar";
+import { getSdk } from "@shared/helpers/stellar";
 import { AssetIcons } from "@shared/api/types";
 import { allAccountsSelector } from "popup/ducks/accountServices";
 
@@ -57,7 +58,6 @@ function useSubmitTxData({
       destination,
       federationAddress,
       destinationAsset,
-      destinationTokenDetails,
       isCollectible,
       collectibleData,
     },
@@ -110,11 +110,24 @@ function useSubmitTxData({
             to_asset_code: getAssetFromCanonical(destinationAsset).code,
           });
           // Trustline added only once the combined changeTrust +
-          // pathPaymentStrictSend transaction confirmed it.
-          if (destinationTokenDetails?.requiresTrustline) {
+          // pathPaymentStrictSend transaction confirmed it. Gate on the
+          // submitted transaction itself rather than the pick-time snapshot —
+          // a defaulted/deep-linked destination has no snapshot, but the
+          // changeTrust op it confirmed is right there in the XDR.
+          const Sdk = getSdk(networkDetails.networkPassphrase);
+          const submittedTx = Sdk.TransactionBuilder.fromXDR(
+            signedXDR,
+            networkDetails.networkPassphrase,
+          );
+          const changeTrustOp =
+            "operations" in submittedTx
+              ? submittedTx.operations.find((op) => op.type === "changeTrust")
+              : undefined;
+          if (changeTrustOp && "line" in changeTrustOp) {
+            const { line } = changeTrustOp;
             emitMetric(METRIC_NAMES.swapTrustlineAdded, {
-              asset_code: destinationTokenDetails.tokenCode,
-              asset_issuer: destinationTokenDetails.issuer,
+              asset_code: "code" in line ? line.code : undefined,
+              asset_issuer: "issuer" in line ? line.issuer : undefined,
             });
           }
         } else {

extension/src/popup/components/amount/AmountCard/index.tsx

@@ -256,9 +256,6 @@ export const AmountCard = ({
             </>
           ) : (
             <>
-              <span className="AmountCard__select-icon">
-                <Icon.Plus />
-              </span>
               <span className="AmountCard__asset-code">{t("Select")}</span>
               <Icon.ChevronDown />
             </>

extension/src/popup/components/amount/AmountCard/styles.scss

@@ -113,11 +113,16 @@
     margin-bottom: 0;
     border: 0;
     color: var(--sds-clr-gray-12);
+    min-height: pxToRem(36px);
 
     &:hover {
       background-color: var(--sds-clr-gray-06);
     }
 
+    &--empty {
+      padding: pxToRem(4px) pxToRem(8px) pxToRem(4px) pxToRem(10px);
+    }
+
     .AccountAssets__asset--logo {
       width: pxToRem(20px) !important;
       height: pxToRem(20px) !important;
@@ -151,28 +156,6 @@
     }
   }
 
-  // Empty "+ Select" state (e.g. the swap receive card before a token is
-  // picked): a circular badge the same footprint (20px + 4px margin) as the
-  // asset logo, with a small plus on a slightly lighter background.
-  &__select-icon {
-    display: inline-flex;
-    align-items: center;
-    justify-content: center;
-    flex-shrink: 0;
-    width: pxToRem(20px);
-    height: pxToRem(20px);
-    margin: pxToRem(4px);
-    border-radius: 50%;
-    background-color: var(--sds-clr-gray-04);
-    // Muted plus, matching the "You receive" label color.
-    color: var(--sds-clr-gray-11);
-
-    svg {
-      width: pxToRem(14px);
-      height: pxToRem(14px);
-    }
-  }
-
   &__asset-code {
     font-size: pxToRem(14px);
     font-weight: var(--font-weight-medium);

extension/src/popup/components/swap/SwapAmount/helpers/getSwapDerivedData.ts

@@ -52,6 +52,11 @@ interface GetSwapDerivedDataParams {
   networkDetails: NetworkDetails;
   inputType: InputType;
   isLiveQuoteLoading: boolean;
+  // Balances-derived "this swap adds a trustline", checked against the
+  // UNFILTERED balances (a hidden held asset needs no new trustline). Drives
+  // the reserve math; distinct from destinationIsNonHeld below, which is a
+  // display-list concept for the direction toggle.
+  destRequiresTrustline: boolean;
 }
 
 /**
@@ -74,6 +79,7 @@ export const getSwapDerivedData = ({
   networkDetails,
   inputType,
   isLiveQuoteLoading,
+  destRequiresTrustline,
 }: GetSwapDerivedDataParams) => {
   const sendData = data;
   const assetIcon = sendData.icons[asset];
@@ -124,7 +130,9 @@ export const getSwapDerivedData = ({
   const availableBalance = deductNewTrustlineReserve({
     spendable: baseAvailableBalance,
     sourceIsXlm: asset === "native",
-    requiresTrustline: destinationTokenDetails?.requiresTrustline ?? false,
+    // The unfiltered-balances flag, NOT destinationIsNonHeld: a hidden held
+    // destination builds no changeTrust, so no reserve should be withheld.
+    requiresTrustline: destRequiresTrustline,
   });
   const displayTotal = `${formatAmount(availableBalance)}`;