diff --git a/force_bdss/api.py b/force_bdss/api.py
index ff4094d31bcc913cd3971369a9f76fd2db89502a..165dd9bdc1869e369d2f0e80a2669224947941d4 100644
--- a/force_bdss/api.py
+++ b/force_bdss/api.py
@@ -5,12 +5,25 @@ from .core.data_value import DataValue  # noqa
 from .core.workflow import Workflow  # noqa
 from .core.slot import Slot  # noqa
 from .core.i_factory import IFactory  # noqa
+from .core.input_slot_info import InputSlotInfo  # noqa
+from .core.output_slot_info import OutputSlotInfo  # noqa
+from .core.kpi_specification import KPISpecification  # noqa
+from .core.execution_layer import ExecutionLayer  # noqa
+from .core.verifier import verify_workflow  # noqa
+from .core.verifier import VerifierError  # noqa
 
 from .data_sources.base_data_source_model import BaseDataSourceModel  # noqa
 from .data_sources.base_data_source import BaseDataSource  # noqa
 from .data_sources.base_data_source_factory import BaseDataSourceFactory  # noqa
 from .data_sources.i_data_source_factory import IDataSourceFactory  # noqa
 
+from .factory_registry_plugin import IFactoryRegistryPlugin  # noqa
+from .factory_registry_plugin import FactoryRegistryPlugin  # noqa
+
+from .io.workflow_reader import WorkflowReader  # noqa
+from .io.workflow_reader import InvalidFileException  # noqa
+from .io.workflow_writer import WorkflowWriter  # noqa
+
 from .mco.base_mco_model import BaseMCOModel  # noqa
 from .mco.base_mco_communicator import BaseMCOCommunicator  # noqa
 from .mco.base_mco import BaseMCO  # noqa
diff --git a/force_bdss/io/tests/test_workflow_writer.py b/force_bdss/io/tests/test_workflow_writer.py
index d2a9d297039661d38b4ca71311ed5a2d062add1f..379af5a686bc03f3988ac56bf43aa857bfa02193 100644
--- a/force_bdss/io/tests/test_workflow_writer.py
+++ b/force_bdss/io/tests/test_workflow_writer.py
@@ -13,8 +13,10 @@ from force_bdss.io.workflow_reader import WorkflowReader
 from force_bdss.tests.dummy_classes.factory_registry_plugin import \
     DummyFactoryRegistryPlugin
 
-from force_bdss.io.workflow_writer import WorkflowWriter, traits_to_dict
+from force_bdss.io.workflow_writer import WorkflowWriter, traits_to_dict,\
+    pop_recursive
 from force_bdss.core.workflow import Workflow
+from force_bdss.core.input_slot_info import InputSlotInfo
 
 
 class TestWorkflowWriter(unittest.TestCase):
@@ -87,3 +89,29 @@ class TestWorkflowWriter(unittest.TestCase):
         mock_traits.__getstate__ = mock.Mock(return_value={"foo": "bar"})
 
         self.assertEqual(traits_to_dict(mock_traits), {"foo": "bar"})
+
+    def test_traits_to_dict(self):
+
+        wfwriter = WorkflowWriter()
+        wf = self._create_workflow()
+        exec_layer = wf.execution_layers[0]
+        exec_layer.data_sources[0].input_slot_info = [InputSlotInfo()]
+        slotdata = exec_layer.data_sources[0].input_slot_info[0].__getstate__()
+        self.assertTrue("__traits_version__" in slotdata)
+        # Calls traits_to_dict for each data source
+        datastore_list = wfwriter._execution_layer_data(exec_layer)
+        new_slotdata = datastore_list[0]['model_data']['input_slot_info']
+        self.assertTrue("__traits_version__" not in new_slotdata)
+
+        test_dictionary = {'K1': {'K1': 'V1', 'K2': 'V2', 'K3': 'V3'},
+                           'K2': ['V1', 'V2', {'K1': 'V1', 'K2': 'V2',
+                                               'K3': 'V3'}],
+                           'K3': 'V3',
+                           'K4': ('V1', {'K3': 'V3'},)}
+
+        result_dictionary = {'K1': {'K1': 'V1', 'K2': 'V2', },
+                             'K2': ['V1', 'V2', {'K1': 'V1', 'K2': 'V2', }],
+                             'K4': ('V1', {},)}
+
+        test_result_dictionary = pop_recursive(test_dictionary, 'K3')
+        self.assertEqual(test_result_dictionary, result_dictionary)
diff --git a/force_bdss/io/workflow_writer.py b/force_bdss/io/workflow_writer.py
index aadd19d2156dc98ca3ea2aff5db5fad7e5e40d0b..ddd90ef4ef5979267aa0c5033d838655cb65b2e9 100644
--- a/force_bdss/io/workflow_writer.py
+++ b/force_bdss/io/workflow_writer.py
@@ -91,10 +91,31 @@ class WorkflowWriter(HasStrictTraits):
 def traits_to_dict(traits_obj):
     """Converts a traits class into a dict, removing the pesky
     traits version."""
+
     state = traits_obj.__getstate__()
+
+    state = pop_recursive(state, '__traits_version__')
+
+    return state
+
+
+def pop_recursive(dictionary, remove_key):
+    """Recursively remove a named key from dictionary and any contained
+    dictionaries."""
     try:
-        state.pop("__traits_version__")
+        dictionary.pop(remove_key)
     except KeyError:
         pass
 
-    return state
+    for key, value in dictionary.items():
+        # If remove_key is in the dict, remove it
+        if isinstance(value, dict):
+            pop_recursive(value, remove_key)
+        # If we have a non-dict iterable which contains a dict,
+        # call pop.(remove_key) from that as well
+        elif isinstance(value, (tuple, list)):
+            for element in value:
+                if isinstance(element, dict):
+                    pop_recursive(element, remove_key)
+
+    return dictionary