diff --git a/hathor/transaction/base_transaction.py b/hathor/transaction/base_transaction.py
index 79104f3d5..68d94ead2 100644
--- a/hathor/transaction/base_transaction.py
+++ b/hathor/transaction/base_transaction.py
@@ -820,6 +820,13 @@ def serialize_output(tx: BaseTransaction, tx_out: TxOutput) -> dict[str, Any]:
             'parents': [],
         }
 
+        # A nano contract tx must be confirmed by one block at least
+        # to be considered "executed"
+        if meta.first_block is not None:
+            ret['first_block'] = meta.first_block.hex()
+        else:
+            ret['first_block'] = None
+
         for parent in self.parents:
             ret['parents'].append(parent.hex())
 
diff --git a/hathor/transaction/resources/dashboard.py b/hathor/transaction/resources/dashboard.py
index 47f366a8e..07add5d21 100644
--- a/hathor/transaction/resources/dashboard.py
+++ b/hathor/transaction/resources/dashboard.py
@@ -152,7 +152,8 @@ def render_GET(self, request):
                                                 ],
                                                 'inputs': [],
                                                 'outputs': [],
-                                                'tokens': []
+                                                'tokens': [],
+                                                'first_block': None,
                                             },
                                             {
                                                 'tx_id': ('00002b3be4e3876e67b5e090d76dcd71'
@@ -166,7 +167,9 @@ def render_GET(self, request):
                                                 ],
                                                 'inputs': [],
                                                 'outputs': [],
-                                                'tokens': []
+                                                'tokens': [],
+                                                'first_block': ('000005af290a55b079014a0be3246479'
+                                                                'e84eeb635f02010dbf3e5f3414a85bbb')
                                             }
                                         ],
                                         'blocks': [
@@ -189,7 +192,9 @@ def render_GET(self, request):
                                                         'script': 'dqkUixvdsajkV6vO+9Jjgjbaheqn016IrA=='
                                                     }
                                                 ],
-                                                'tokens': []
+                                                'tokens': [],
+                                                'first_block': ('000005af290a55b079014a0be3246479'
+                                                                'e84eeb635f02010dbf3e5f3414a85bbb')
                                             },
                                             {
                                                 'tx_id': ('00035e46a20d0ecbda0dc6fdcaa243e9'
@@ -210,7 +215,9 @@ def render_GET(self, request):
                                                         'script': 'dqkUdNQbj29Md1xsAYinK+RsDJCCB7eIrA=='
                                                     }
                                                 ],
-                                                'tokens': []
+                                                'tokens': [],
+                                                'first_block': ('000005af290a55b079014a0be3246479'
+                                                                'e84eeb635f02010dbf3e5f3414a85bbb')
                                             },
                                             {
                                                 'tx_id': ('000133cc80b625b1babbd454edc3474e'
@@ -231,7 +238,8 @@ def render_GET(self, request):
                                                         'script': 'dqkU0AoLEAX+1b36s+VyaMc9bkj/5byIrA=='
                                                     }
                                                 ],
-                                                'tokens': []
+                                                'tokens': [],
+                                                'first_block': None
                                             }
                                         ]
                                     }
diff --git a/hathor/transaction/resources/transaction.py b/hathor/transaction/resources/transaction.py
index 796030c0d..816185438 100644
--- a/hathor/transaction/resources/transaction.py
+++ b/hathor/transaction/resources/transaction.py
@@ -465,6 +465,7 @@ def get_list_tx(self, request):
                                                 ],
                                                 'tokens': [],
                                                 'height': 12345,
+                                                'first_block': None
                                             },
                                             {
                                                 'tx_id': ('00000b8792cb13e8adb51cc7d866541f'
@@ -496,7 +497,9 @@ def get_list_tx(self, request):
                                                         'script': 'dqkUjjPg+zwG6JDe901I0ybQxcAPrAuIrA=='
                                                     }
                                                 ],
-                                                'tokens': []
+                                                'tokens': [],
+                                                'first_block': ('000005af290a55b079014a0be3246479'
+                                                                'e84eeb635f02010dbf3e5f3414a85bbb')
                                             }
                                         ],
                                         'has_more': True
diff --git a/hathor/wallet/resources/thin_wallet/address_history.py b/hathor/wallet/resources/thin_wallet/address_history.py
index 044494bb0..e7e231e71 100644
--- a/hathor/wallet/resources/thin_wallet/address_history.py
+++ b/hathor/wallet/resources/thin_wallet/address_history.py
@@ -321,8 +321,10 @@ def get_address_history(self, addresses: list[str], ref_hash: Optional[str]) ->
                                                             },
                                                         "token": "00"
                                                         }
-                                                    ]
-                                                }
+                                                    ],
+                                                "first_block": ("000005af290a55b079014a0be3246479"
+                                                                "e84eeb635f02010dbf3e5f3414a85bbb")
+                                            }
                                         ]
                                     }
                                 },
diff --git a/hathor/wallet/resources/thin_wallet/token_history.py b/hathor/wallet/resources/thin_wallet/token_history.py
index a68cf4077..603a6c7f6 100644
--- a/hathor/wallet/resources/thin_wallet/token_history.py
+++ b/hathor/wallet/resources/thin_wallet/token_history.py
@@ -243,7 +243,8 @@ def render_GET(self, request: Request) -> bytes:
                                                         'script': 'dqkUjjPg+zwG6JDe901I0ybQxcAPrAuIrA=='
                                                     }
                                                 ],
-                                                'tokens': []
+                                                'tokens': [],
+                                                'first_block': None
                                             },
                                             {
                                                 'tx_id': ('00000b8792cb13e8adb51cc7d866541f'
@@ -276,7 +277,9 @@ def render_GET(self, request: Request) -> bytes:
                                                         'script': 'dqkUjjPg+zwG6JDe901I0ybQxcAPrAuIrA=='
                                                     }
                                                 ],
-                                                'tokens': []
+                                                'tokens': [],
+                                                'first_block': ('000005af290a55b079014a0be3246479'
+                                                                'e84eeb635f02010dbf3e5f3414a85bbb')
                                             }
                                         ],
                                         'has_more': True