Get USDC balance

src/backend/backend.did

@@ -5,6 +5,7 @@ type Result_4 = variant { Ok : nat64; Err : text };
 
 service : {
   get_address : () -> (Result);
+  get_balance_usdc : (opt text) -> (Result);
   get_balance : (opt text) -> (Result);
   get_batch_balances : (vec text) -> (Result);
   get_latest_block : () -> (Result);

src/backend/src/service/get_balance_usdc.rs

@@ -0,0 +1,44 @@
+use alloy::{
+    network::TxSigner,
+    primitives::{address, Address},
+    providers::ProviderBuilder,
+    sol,
+    transports::icp::IcpConfig,
+};
+
+use crate::{create_icp_sepolia_signer, get_rpc_service_sepolia};
+
+// Codegen from ABI file to interact with the contract.
+sol!(
+    #[allow(missing_docs, clippy::too_many_arguments)]
+    #[sol(rpc)]
+    USDC,
+    "abi/USDC.json"
+);
+
+/// Request the balance of an ETH account.
+#[ic_cdk::update]
+async fn get_balance_usdc(address: Option<String>) -> Result<String, String> {
+    let address = match address {
+        Some(val) => val,
+        None => {
+            let signer = create_icp_sepolia_signer().await;
+            signer.address().to_string()
+        }
+    };
+    let address = address.parse::<Address>().map_err(|e| e.to_string())?;
+    let rpc_service = get_rpc_service_sepolia();
+    let config = IcpConfig::new(rpc_service);
+    let provider = ProviderBuilder::new().on_icp(config);
+
+    let contract = USDC::new(
+        address!("1c7d4b196cb0c7b01d743fbc6116a902379c7238"),
+        provider,
+    );
+
+    let result = contract.balanceOf(address).call().await;
+    match result {
+        Ok(balance) => Ok(balance._0.to_string()),
+        Err(e) => Err(e.to_string()),
+    }
+}

src/backend/src/service/mod.rs

@@ -1,5 +1,6 @@
 mod get_address;
 mod get_balance;
+mod get_balance_usdc;
 mod get_batch_balances;
 mod get_latest_block;
 mod send_eth;

src/backend/src/service/watch_usdc_transfer.rs

@@ -11,7 +11,6 @@ use alloy::{
     transports::icp::IcpConfig,
 };
 use ic_cdk_timers::TimerId;
-use USDC::Transfer;
 
 const POLL_LIMIT: usize = 3;
 
@@ -105,7 +104,7 @@ async fn watch_usdc_transfer_start() -> Result<String, String> {
         .address(usdt_token_address)
         // By specifying an `event` or `event_signature` we listen for a specific event of the
         // contract. In this case the `Transfer(address,address,uint256)` event.
-        .event(Transfer::SIGNATURE)
+        .event(USDC::Transfer::SIGNATURE)
         .from_block(BlockNumberOrTag::Latest);
 
     // Initialize the poller and start watching

src/frontend/routeTree.gen.ts

@@ -23,6 +23,7 @@ const SendethwithfillersLazyImport = createFileRoute('/send_eth_with_fillers')()
 const SendethLazyImport = createFileRoute('/send_eth')()
 const GetlatestblockLazyImport = createFileRoute('/get_latest_block')()
 const GetbatchbalancesLazyImport = createFileRoute('/get_batch_balances')()
+const GetbalanceusdcLazyImport = createFileRoute('/get_balance_usdc')()
 const GetbalanceLazyImport = createFileRoute('/get_balance')()
 const GetaddressLazyImport = createFileRoute('/get_address')()
 const IndexLazyImport = createFileRoute('/')()
@@ -72,6 +73,13 @@ const GetbatchbalancesLazyRoute = GetbatchbalancesLazyImport.update({
   import('./routes/get_batch_balances.lazy').then((d) => d.Route),
 )
 
+const GetbalanceusdcLazyRoute = GetbalanceusdcLazyImport.update({
+  path: '/get_balance_usdc',
+  getParentRoute: () => rootRoute,
+} as any).lazy(() =>
+  import('./routes/get_balance_usdc.lazy').then((d) => d.Route),
+)
+
 const GetbalanceLazyRoute = GetbalanceLazyImport.update({
   path: '/get_balance',
   getParentRoute: () => rootRoute,
@@ -112,6 +120,13 @@ declare module '@tanstack/react-router' {
       preLoaderRoute: typeof GetbalanceLazyImport
       parentRoute: typeof rootRoute
     }
+    '/get_balance_usdc': {
+      id: '/get_balance_usdc'
+      path: '/get_balance_usdc'
+      fullPath: '/get_balance_usdc'
+      preLoaderRoute: typeof GetbalanceusdcLazyImport
+      parentRoute: typeof rootRoute
+    }
     '/get_batch_balances': {
       id: '/get_batch_balances'
       path: '/get_batch_balances'
@@ -170,6 +185,7 @@ export interface FileRoutesByFullPath {
   '/': typeof IndexLazyRoute
   '/get_address': typeof GetaddressLazyRoute
   '/get_balance': typeof GetbalanceLazyRoute
+  '/get_balance_usdc': typeof GetbalanceusdcLazyRoute
   '/get_batch_balances': typeof GetbatchbalancesLazyRoute
   '/get_latest_block': typeof GetlatestblockLazyRoute
   '/send_eth': typeof SendethLazyRoute
@@ -183,6 +199,7 @@ export interface FileRoutesByTo {
   '/': typeof IndexLazyRoute
   '/get_address': typeof GetaddressLazyRoute
   '/get_balance': typeof GetbalanceLazyRoute
+  '/get_balance_usdc': typeof GetbalanceusdcLazyRoute
   '/get_batch_balances': typeof GetbatchbalancesLazyRoute
   '/get_latest_block': typeof GetlatestblockLazyRoute
   '/send_eth': typeof SendethLazyRoute
@@ -197,6 +214,7 @@ export interface FileRoutesById {
   '/': typeof IndexLazyRoute
   '/get_address': typeof GetaddressLazyRoute
   '/get_balance': typeof GetbalanceLazyRoute
+  '/get_balance_usdc': typeof GetbalanceusdcLazyRoute
   '/get_batch_balances': typeof GetbatchbalancesLazyRoute
   '/get_latest_block': typeof GetlatestblockLazyRoute
   '/send_eth': typeof SendethLazyRoute
@@ -212,6 +230,7 @@ export interface FileRouteTypes {
     | '/'
     | '/get_address'
     | '/get_balance'
+    | '/get_balance_usdc'
     | '/get_batch_balances'
     | '/get_latest_block'
     | '/send_eth'
@@ -224,6 +243,7 @@ export interface FileRouteTypes {
     | '/'
     | '/get_address'
     | '/get_balance'
+    | '/get_balance_usdc'
     | '/get_batch_balances'
     | '/get_latest_block'
     | '/send_eth'
@@ -236,6 +256,7 @@ export interface FileRouteTypes {
     | '/'
     | '/get_address'
     | '/get_balance'
+    | '/get_balance_usdc'
     | '/get_batch_balances'
     | '/get_latest_block'
     | '/send_eth'
@@ -250,6 +271,7 @@ export interface RootRouteChildren {
   IndexLazyRoute: typeof IndexLazyRoute
   GetaddressLazyRoute: typeof GetaddressLazyRoute
   GetbalanceLazyRoute: typeof GetbalanceLazyRoute
+  GetbalanceusdcLazyRoute: typeof GetbalanceusdcLazyRoute
   GetbatchbalancesLazyRoute: typeof GetbatchbalancesLazyRoute
   GetlatestblockLazyRoute: typeof GetlatestblockLazyRoute
   SendethLazyRoute: typeof SendethLazyRoute
@@ -263,6 +285,7 @@ const rootRouteChildren: RootRouteChildren = {
   IndexLazyRoute: IndexLazyRoute,
   GetaddressLazyRoute: GetaddressLazyRoute,
   GetbalanceLazyRoute: GetbalanceLazyRoute,
+  GetbalanceusdcLazyRoute: GetbalanceusdcLazyRoute,
   GetbatchbalancesLazyRoute: GetbatchbalancesLazyRoute,
   GetlatestblockLazyRoute: GetlatestblockLazyRoute,
   SendethLazyRoute: SendethLazyRoute,
@@ -287,6 +310,7 @@ export const routeTree = rootRoute
         "/",
         "/get_address",
         "/get_balance",
+        "/get_balance_usdc",
         "/get_batch_balances",
         "/get_latest_block",
         "/send_eth",
@@ -305,6 +329,9 @@ export const routeTree = rootRoute
     "/get_balance": {
       "filePath": "get_balance.lazy.tsx"
     },
+    "/get_balance_usdc": {
+      "filePath": "get_balance_usdc.lazy.tsx"
+    },
     "/get_batch_balances": {
       "filePath": "get_batch_balances.lazy.tsx"
     },

src/frontend/routes/get_balance_usdc.lazy.tsx

@@ -0,0 +1,49 @@
+import { Link, createLazyFileRoute } from "@tanstack/react-router";
+
+import { backend } from "../../backend/declarations";
+import { useQuery } from "@tanstack/react-query";
+import { useState } from "react";
+import Source from "../components/source";
+import Spinner from "../components/spinner";
+
+export const Route = createLazyFileRoute("/get_balance_usdc")({
+  component: Page,
+});
+
+function Page() {
+  const [ethAddress, setEthAddress] = useState<string>("");
+
+  const {
+    data: accountBalanceResult,
+    isFetching: isFetchingAccountBalance,
+    refetch: refetchAccountBalance,
+  } = useQuery({
+    queryKey: ["get_balance_usdc", ethAddress],
+    queryFn: () => backend.get_balance_usdc([ethAddress]),
+    enabled: false,
+  });
+
+  return (
+    <>
+      <Link to="/">
+        <button> Menu</button>
+      </Link>
+      <div className="card">
+        <p>Request the USDC balance of an ETH account.</p>
+        <input
+          type="text"
+          placeholder="ETH address"
+          onChange={(e) => setEthAddress(e.target.value)}
+          value={ethAddress}
+        />
+        <button disabled={isFetchingAccountBalance} onClick={() => void refetchAccountBalance()}>
+          {isFetchingAccountBalance ? <Spinner /> : "get_balance_usdc(ethAddress)"}
+        </button>
+        {accountBalanceResult && (
+          <pre>{JSON.stringify(accountBalanceResult, null, 2)}</pre>
+        )}
+        <Source file="get_balance_usdc.rs" />
+      </div>
+    </>
+  );
+}

src/frontend/routes/index.lazy.tsx

@@ -16,6 +16,9 @@ function Index() {
       <Link to="/get_balance">
         <button>get_balance(address)</button>
       </Link>
+      <Link to="/get_balance_usdc">
+        <button>get_balance_usdc(address)</button>
+      </Link>
       <Link to="/get_batch_balances">
         <button>get_batch_balances([address1, address2])</button>
       </Link>