diff --git a/.github/workflows/pr_test_build.yml b/.github/workflows/pr_test_build.yml
index 282941365..ddc8869f0 100644
--- a/.github/workflows/pr_test_build.yml
+++ b/.github/workflows/pr_test_build.yml
@@ -143,7 +143,7 @@ jobs:
           echo "const chatwootWebsiteToken = '${{ secrets.CHATWOOT_WEBSITE_TOKEN }}';" >> lib/.secrets.g.dart
           echo "const exolixApiKey = '${{ secrets.EXOLIX_API_KEY }}';" >> lib/.secrets.g.dart
           echo "const robinhoodApplicationId = '${{ secrets.ROBINHOOD_APPLICATION_ID }}';" >> lib/.secrets.g.dart
-          echo "const robinhoodCIdApiSecret = '${{ secrets.ROBINHOOD_CID_CLIENT_SECRET }}';" >> lib/.secrets.g.dart
+          echo "const exchangeHelperApiKey = '${{ secrets.ROBINHOOD_CID_CLIENT_SECRET }}';" >> lib/.secrets.g.dart
           echo "const walletConnectProjectId = '${{ secrets.WALLET_CONNECT_PROJECT_ID }}';" >> lib/.secrets.g.dart
           echo "const moralisApiKey = '${{ secrets.MORALIS_API_KEY }}';" >> lib/.secrets.g.dart
           echo "const polygonScanApiKey = '${{ secrets.POLYGON_SCAN_API_KEY }}';" >> cw_evm/lib/.secrets.g.dart
diff --git a/cw_solana/lib/solana_wallet.dart b/cw_solana/lib/solana_wallet.dart
index 3476d76cd..de4d70674 100644
--- a/cw_solana/lib/solana_wallet.dart
+++ b/cw_solana/lib/solana_wallet.dart
@@ -1,6 +1,5 @@
 import 'dart:async';
 import 'dart:convert';
-import 'dart:developer';
 import 'dart:io';
 import 'package:cw_core/cake_hive.dart';
 import 'package:cw_core/crypto_currency.dart';
@@ -30,7 +29,6 @@ import 'package:mobx/mobx.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'package:solana/metaplex.dart' as metaplex;
 import 'package:solana/solana.dart';
-import 'package:web3dart/crypto.dart';
 
 part 'solana_wallet.g.dart';
 
@@ -134,7 +132,7 @@ abstract class SolanaWalletBase
     assert(mnemonic != null || privateKey != null);
 
     if (privateKey != null) {
-      final privateKeyBytes = hexToBytes(privateKey);
+      final privateKeyBytes = HEX.decode(privateKey);
       return await Wallet.fromPrivateKeyBytes(privateKey: privateKeyBytes);
     }
 
@@ -491,7 +489,7 @@ abstract class SolanaWalletBase
     final signature = await _walletKeyPair!.sign(messageBytes);
 
     // Convert the signature to a hexadecimal string
-    final hex = bytesToHex(signature.bytes);
+    final hex = HEX.encode(signature.bytes);
 
     return hex;
   }
diff --git a/cw_solana/pubspec.yaml b/cw_solana/pubspec.yaml
index c98b7492e..7e24983bf 100644
--- a/cw_solana/pubspec.yaml
+++ b/cw_solana/pubspec.yaml
@@ -19,7 +19,6 @@ dependencies:
   bip39: ^1.0.6
   mobx: ^2.3.0+1
   shared_preferences: ^2.0.15
-  web3dart: ^2.7.1
   bip32: ^2.0.0
   hex: ^0.2.0
 
@@ -34,4 +33,4 @@ dev_dependencies:
 flutter:
   # assets:
   #   - images/a_dot_burr.jpeg
-  #   - images/a_dot_ham.jpeg
\ No newline at end of file
+  #   - images/a_dot_ham.jpeg
diff --git a/lib/buy/moonpay/moonpay_provider.dart b/lib/buy/moonpay/moonpay_provider.dart
index 75ba45ce1..02bdedaec 100644
--- a/lib/buy/moonpay/moonpay_provider.dart
+++ b/lib/buy/moonpay/moonpay_provider.dart
@@ -1,4 +1,13 @@
 import 'dart:convert';
+
+import 'package:cake_wallet/.secrets.g.dart' as secrets;
+import 'package:cake_wallet/buy/buy_amount.dart';
+import 'package:cake_wallet/buy/buy_exception.dart';
+import 'package:cake_wallet/buy/buy_provider.dart';
+import 'package:cake_wallet/buy/buy_provider_description.dart';
+import 'package:cake_wallet/buy/order.dart';
+import 'package:cake_wallet/exchange/trade_state.dart';
+import 'package:cake_wallet/generated/i18n.dart';
 import 'package:cake_wallet/palette.dart';
 import 'package:cake_wallet/routes.dart';
 import 'package:cake_wallet/src/widgets/alert_with_one_action.dart';
@@ -6,19 +15,11 @@ import 'package:cake_wallet/store/settings_store.dart';
 import 'package:cake_wallet/themes/theme_base.dart';
 import 'package:cake_wallet/utils/device_info.dart';
 import 'package:crypto/crypto.dart';
-import 'package:cake_wallet/buy/buy_exception.dart';
-import 'package:cake_wallet/generated/i18n.dart';
-import 'package:flutter/material.dart';
-import 'package:http/http.dart';
-import 'package:cake_wallet/buy/buy_amount.dart';
-import 'package:cake_wallet/buy/buy_provider.dart';
-import 'package:cake_wallet/buy/buy_provider_description.dart';
-import 'package:cake_wallet/buy/order.dart';
+import 'package:cw_core/crypto_currency.dart';
 import 'package:cw_core/wallet_base.dart';
 import 'package:cw_core/wallet_type.dart';
-import 'package:cake_wallet/exchange/trade_state.dart';
-import 'package:cake_wallet/.secrets.g.dart' as secrets;
-import 'package:cw_core/crypto_currency.dart';
+import 'package:flutter/material.dart';
+import 'package:http/http.dart';
 import 'package:url_launcher/url_launcher.dart';
 
 class MoonPaySellProvider extends BuyProvider {
@@ -34,6 +35,7 @@ class MoonPaySellProvider extends BuyProvider {
 
   static const _baseTestUrl = 'sell-sandbox.moonpay.com';
   static const _baseProductUrl = 'sell.moonpay.com';
+  static const _cIdBaseUrl = 'exchange-helper.cakewallet.com';
 
   @override
   String get providerDescription =>
@@ -60,9 +62,29 @@ class MoonPaySellProvider extends BuyProvider {
 
   static String get _apiKey => secrets.moonPayApiKey;
 
-  static String get _secretKey => secrets.moonPaySecretKey;
+  static String get _exchangeHelperApiKey => secrets.exchangeHelperApiKey;
   final String baseUrl;
 
+  Future<String> getMoonpaySignature(String query) async {
+    final uri = Uri.https(_cIdBaseUrl, "/api/moonpay");
+
+    final response = await post(
+      uri,
+      headers: {
+        'Content-Type': 'application/json',
+        'x-api-key': _exchangeHelperApiKey,
+      },
+      body: json.encode({'query': query}),
+    );
+
+    if (response.statusCode == 200) {
+      return (jsonDecode(response.body) as Map<String, dynamic>)['signature'] as String;
+    } else {
+      throw Exception(
+          'Provider currently unavailable. Status: ${response.statusCode} ${response.body}');
+    }
+  }
+
   Future<Uri> requestMoonPayUrl({
     required CryptoCurrency currency,
     required String refundWalletAddress,
@@ -86,11 +108,7 @@ class MoonPaySellProvider extends BuyProvider {
       }..addAll(customParams),
     );
 
-    final messageBytes = utf8.encode('?${originalUri.query}');
-    final key = utf8.encode(_secretKey);
-    final hmac = Hmac(sha256, key);
-    final digest = hmac.convert(messageBytes);
-    final signature = base64.encode(digest.bytes);
+    final signature = await getMoonpaySignature('?${originalUri.query}');
 
     if (isTestEnvironment) {
       return originalUri;
diff --git a/lib/buy/robinhood/robinhood_buy_provider.dart b/lib/buy/robinhood/robinhood_buy_provider.dart
index 47c3ab1ea..7610e51f3 100644
--- a/lib/buy/robinhood/robinhood_buy_provider.dart
+++ b/lib/buy/robinhood/robinhood_buy_provider.dart
@@ -32,11 +32,12 @@ class RobinhoodBuyProvider extends BuyProvider {
 
   String get _applicationId => secrets.robinhoodApplicationId;
 
-  String get _apiSecret => secrets.robinhoodCIdApiSecret;
+  String get _apiSecret => secrets.exchangeHelperApiKey;
 
   String getSignature(String message) {
     switch (wallet.type) {
       case WalletType.ethereum:
+      case WalletType.polygon:
         return wallet.signMessage(message);
       case WalletType.litecoin:
       case WalletType.bitcoin:
diff --git a/lib/entities/provider_types.dart b/lib/entities/provider_types.dart
index b7336c2a7..f3993e129 100644
--- a/lib/entities/provider_types.dart
+++ b/lib/entities/provider_types.dart
@@ -55,6 +55,7 @@ class ProvidersHelper {
       case WalletType.monero:
         return [ProviderType.askEachTime, ProviderType.onramper, ProviderType.dfx];
       case WalletType.bitcoin:
+      case WalletType.polygon:
       case WalletType.ethereum:
         return [
           ProviderType.askEachTime,
@@ -65,8 +66,6 @@ class ProvidersHelper {
       case WalletType.litecoin:
       case WalletType.bitcoinCash:
         return [ProviderType.askEachTime, ProviderType.onramper, ProviderType.robinhood];
-      case WalletType.polygon:
-        return [ProviderType.askEachTime, ProviderType.onramper, ProviderType.dfx];
       case WalletType.solana:
         return [ProviderType.askEachTime, ProviderType.onramper, ProviderType.robinhood];
       case WalletType.none:
@@ -79,6 +78,7 @@ class ProvidersHelper {
     switch (walletType) {
       case WalletType.bitcoin:
       case WalletType.ethereum:
+      case WalletType.polygon:
         return [
           ProviderType.askEachTime,
           ProviderType.onramper,
@@ -88,13 +88,6 @@ class ProvidersHelper {
       case WalletType.litecoin:
       case WalletType.bitcoinCash:
         return [ProviderType.askEachTime, ProviderType.moonpaySell];
-      case WalletType.polygon:
-        return [
-          ProviderType.askEachTime,
-          ProviderType.onramper,
-          ProviderType.moonpaySell,
-          ProviderType.dfx,
-        ];
       case WalletType.solana:
         return [
           ProviderType.askEachTime,
diff --git a/tool/utils/secret_key.dart b/tool/utils/secret_key.dart
index 38b5129af..430de03b6 100644
--- a/tool/utils/secret_key.dart
+++ b/tool/utils/secret_key.dart
@@ -34,7 +34,7 @@ class SecretKey {
     SecretKey('chatwootWebsiteToken', () => ''),
     SecretKey('exolixApiKey', () => ''),
     SecretKey('robinhoodApplicationId', () => ''),
-    SecretKey('robinhoodCIdApiSecret', () => ''),
+    SecretKey('exchangeHelperApiKey', () => ''),
     SecretKey('walletConnectProjectId', () => ''),
     SecretKey('moralisApiKey', () => ''),
   ];