diff --git a/CHANGELOG.md b/CHANGELOG.md
index c4df90d..673b797 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 ## 4.0.1
 
 - Resolve issues with TRON model deserialization on the web.
+- Add amount to `ADATransactionOutput` model #9
 
 
 ## 4.0.0
diff --git a/example/lib/a.dart b/example/lib/a.dart
new file mode 100644
index 0000000..e7d3ab9
--- /dev/null
+++ b/example/lib/a.dart
@@ -0,0 +1,16 @@
+// tag 32 4 0
+// decodeLength0 5 10002220000} start e087b7a12530013806400148e0bc8bc3983250e0f4a4ec9832a2010e4d5254205445535420544f4b454eaa011d68747470733a2f2f6769746875622e636f6d2f6d72746e6574776f726b
+// tag 48 6 0
+// decodeLength0 1 1} start 013806400148e0bc8bc3983250e0f4a4ec9832a2010e4d5254205445535420544f4b454eaa011d68747470733a2f2f6769746875622e636f6d2f6d72746e6574776f726b
+// tag 56 7 0
+// decodeLength0 1 6} start 06400148e0bc8bc3983250e0f4a4ec9832a2010e4d5254205445535420544f4b454eaa011d68747470733a2f2f6769746875622e636f6d2f6d72746e6574776f726b
+// tag 64 8 0
+// decodeLength0 1 1} start 0148e0bc8bc3983250e0f4a4ec9832a2010e4d5254205445535420544f4b454eaa011d68747470733a2f2f6769746875622e636f6d2f6d72746e6574776f726b
+// tag 72 9 0
+// decodeLength0 6 1724570066528} start e0bc8bc3983250e0f4a4ec9832a2010e4d5254205445535420544f4b454eaa011d68747470733a2f2f6769746875622e636f6d2f6d72746e6574776f726b
+// tag 80 10 0
+// decodeLength0 6 1724656466528} start e0f4a4ec9832a2010e4d5254205445535420544f4b454eaa011d68747470733a2f2f6769746875622e636f6d2f6d72746e6574776f726b
+// tag 162 20 2
+// decodeLength2 1 0e4d5254205445535420544f4b45 0e4d5254205445535420544f4b454eaa011d68747470733a2f2f6769746875622e636f6d2f6d72746e6574776f726b
+// tag 170 21 2
+// decodeLength2 1 1d68747470733a2f2f6769746875622e636f6d2f6d72746e6574776f72 1d68747470733a2f2f6769746875622e636f6d2f6d72746e6574776f726b
diff --git a/lib/ada/src/provider/blockfrost/models/models/transaction_utxos.dart b/lib/ada/src/provider/blockfrost/models/models/transaction_utxos.dart
index 7e15839..97e89f8 100644
--- a/lib/ada/src/provider/blockfrost/models/models/transaction_utxos.dart
+++ b/lib/ada/src/provider/blockfrost/models/models/transaction_utxos.dart
@@ -8,7 +8,7 @@ class ADATransactionUTXOSResponse {
   /// List of outputs
   final List<ADATransactionOutput> outputs;
 
-  ADATransactionUTXOSResponse({
+  const ADATransactionUTXOSResponse({
     required this.hash,
     required this.inputs,
     required this.outputs,
@@ -16,12 +16,11 @@ class ADATransactionUTXOSResponse {
 
   factory ADATransactionUTXOSResponse.fromJson(Map<String, dynamic> json) {
     return ADATransactionUTXOSResponse(
-      hash: json['hash'],
-      inputs: List<ADATransactionInput>.from((json['inputs'] as List)
-          .map((inputJson) => ADATransactionInput.fromJson(inputJson))),
-      outputs: List<ADATransactionOutput>.from((json['outputs'] as List)
-          .map((outputJson) => ADATransactionOutput.fromJson(outputJson))),
-    );
+        hash: json['hash'],
+        inputs: List<ADATransactionInput>.from((json['inputs'] as List)
+            .map((inputJson) => ADATransactionInput.fromJson(inputJson))),
+        outputs: List<ADATransactionOutput>.from((json['outputs'] as List)
+            .map((outputJson) => ADATransactionOutput.fromJson(outputJson))));
   }
 
   Map<String, dynamic> toJson() {
@@ -63,10 +62,14 @@ class ADATransactionInput {
   /// Whether the input is a reference transaction input
   final bool reference;
 
+  /// inputs amounts
+  final List<ADATransactionAmount> amount;
+
   ADATransactionInput({
     required this.address,
     required this.txHash,
     required this.outputIndex,
+    required this.amount,
     this.dataHash,
     this.inlineDatum,
     this.referenceScriptHash,
@@ -84,6 +87,10 @@ class ADATransactionInput {
       referenceScriptHash: json['reference_script_hash'],
       collateral: json['collateral'],
       reference: json['reference'],
+      amount: (json['amount'] as List?)
+              ?.map((e) => ADATransactionAmount.fromJson(e))
+              .toList() ??
+          [],
     );
   }
 
@@ -97,6 +104,7 @@ class ADATransactionInput {
       'reference_script_hash': referenceScriptHash,
       'collateral': collateral,
       'reference': reference,
+      'amount': amount.map((e) => e.toJson()).toList()
     };
   }
 
@@ -125,9 +133,13 @@ class ADATransactionOutput {
   /// The hash of the reference script of the output
   final String? referenceScriptHash;
 
+  /// output amounts
+  final List<ADATransactionAmount> amount;
+
   ADATransactionOutput({
     required this.address,
     required this.outputIndex,
+    required this.amount,
     this.dataHash,
     this.inlineDatum,
     required this.collateral,
@@ -142,6 +154,10 @@ class ADATransactionOutput {
       inlineDatum: json['inline_datum'],
       collateral: json['collateral'],
       referenceScriptHash: json['reference_script_hash'],
+      amount: (json['amount'] as List?)
+              ?.map((e) => ADATransactionAmount.fromJson(e))
+              .toList() ??
+          [],
     );
   }
 
@@ -153,6 +169,7 @@ class ADATransactionOutput {
       'inline_datum': inlineDatum,
       'collateral': collateral,
       'reference_script_hash': referenceScriptHash,
+      'amount': amount.map((e) => e.toJson()).toList()
     };
   }
 
@@ -161,3 +178,15 @@ class ADATransactionOutput {
     return "ADATransactionOutput${toJson()}";
   }
 }
+
+class ADATransactionAmount {
+  final String unit;
+  final String quantity;
+  const ADATransactionAmount({required this.unit, required this.quantity});
+  factory ADATransactionAmount.fromJson(Map<String, dynamic> json) {
+    return ADATransactionAmount(unit: json["unit"], quantity: json["quantity"]);
+  }
+  Map<String, dynamic> toJson() {
+    return {"unit": unit, "quantity": quantity};
+  }
+}
diff --git a/lib/tron/src/protbuf/decoder.dart b/lib/tron/src/protbuf/decoder.dart
index 2c73775..03e0291 100644
--- a/lib/tron/src/protbuf/decoder.dart
+++ b/lib/tron/src/protbuf/decoder.dart
@@ -70,7 +70,7 @@ class ProtocolBufferDecoder {
 
   static _Result _decodeInt(List<int> data) {
     final index = data.indexWhere((element) => (element & 0x80) == 0);
-    if (index <= 4) {
+    if (index < 4) {
       return _decodeVarint(data);
     }
     return _decodeBigVarint(data);
@@ -176,6 +176,8 @@ extension QuickProtocolBufferResult on ProtocolBufferDecoderResult {
         }
         return (value == 1 ? true : false) as T;
       }
+    } else if (value is BigInt && 0 is T) {
+      return (value as BigInt).toInt() as T;
     }
     throw TronPluginException("Invalid type.",
         details: {"type": "$T", "Excepted": value.runtimeType.toString()});
diff --git a/test/tron/json_buff_serialization_test.dart b/test/tron/json_buff_serialization_test.dart
index 1e9732a..a300e08 100644
--- a/test/tron/json_buff_serialization_test.dart
+++ b/test/tron/json_buff_serialization_test.dart
@@ -1,3 +1,4 @@
+import 'package:blockchain_utils/blockchain_utils.dart';
 import 'package:on_chain/tron/tron.dart';
 import 'package:test/test.dart';
 
@@ -83,7 +84,8 @@ void issueTrc10() {
     final transaction = Transaction.fromJson(issueJson);
     expect(transaction.rawData.txID,
         "f8c7adadffe7b5baed4169287eaa9088739a66bec193855265e84d3f4ce29d4c");
-    final decBuffer = Transaction.deserialize(transaction.toBuffer());
+    final decBuffer = Transaction.deserialize(BytesUtils.fromHexString(
+        "0aca010a02f5b722086b94058b90a9d3894098958fc398325aab01080612a6010a2f747970652e676f6f676c65617069732e636f6d2f70726f746f636f6c2e41737365744973737565436f6e747261637412730a1541084937b3f86ea7bbca86f2809809a65ed8a7ada9120a4d52544e4554574f524b1a034d525420e087b7a12530013806400148e0bc8bc3983250e0f4a4ec9832a2010e4d5254205445535420544f4b454eaa011d68747470733a2f2f6769746875622e636f6d2f6d72746e6574776f726b70b8c08bc39832"));
     expect(transaction.rawData.txID, decBuffer.rawData.txID);
     final decodeJson = Transaction.fromJson(decBuffer.toJson());
     expect(transaction.rawData.txID, decodeJson.rawData.txID);