Fixed bug when defining shots as int64

qiskit_ibm_runtime/utils/json.py

@@ -207,6 +207,8 @@ def default(self, obj: Any) -> Any:  # pylint: disable=arguments-differ
                 return {"__type__": "ndarray", "__value__": obj.tolist()}
             value = _serialize_and_encode(obj, np.save, allow_pickle=False)
             return {"__type__": "ndarray", "__value__": value}
+        if isinstance(obj, np.int64):
+            return obj.item()
         if isinstance(obj, set):
             return {"__type__": "set", "__value__": list(obj)}
         if isinstance(obj, Result):

releasenotes/notes/fix_np_int64-864b605a88f57419.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Fixed a bug where ``shots`` passed in as a numpy type were not being
+    serialized correctly.

test/unit/test_data_serialization.py

@@ -186,6 +186,13 @@ def test_encoder_instruction(self):
             decoded = json.loads(encoded, cls=RuntimeDecoder)
             self.assertEqual(decoded, obj)
 
+    def test_encoder_np_number(self):
+        """Test encoding and decoding instructions"""
+        encoded = json.dumps(np.int64(100), cls=RuntimeEncoder)
+        self.assertIsInstance(encoded, str)
+        decoded = json.loads(encoded, cls=RuntimeDecoder)
+        self.assertEqual(decoded, 100)
+
     def test_encoder_callable(self):
         """Test encoding a callable."""
         with warnings.catch_warnings(record=True) as warn_cm: