diff --git a/compass/db/api/adapter_holder.py b/compass/db/api/adapter_holder.py
index 185eeb74..ebd4b666 100644
--- a/compass/db/api/adapter_holder.py
+++ b/compass/db/api/adapter_holder.py
@@ -95,7 +95,7 @@ def _filter_adapters(adapter_config, filter_name, filter_value):
     roles=RESP_ROLES_FIELDS,
     flavors=RESP_FLAVORS_FIELDS
 )
-def list_adapters(session, lister, **filters):
+def list_adapters(lister, session=None, **filters):
     """list adapters."""
     if not ADAPTER_MAPPING:
         load_adapters_internal(session)
@@ -125,6 +125,6 @@ def get_adapter_internal(session, adapter_id):
     roles=RESP_ROLES_FIELDS,
     flavors=RESP_FLAVORS_FIELDS
 )
-def get_adapter(session, getter, adapter_id, **kwargs):
+def get_adapter(getter, adapter_id, session=None, **kwargs):
     """get adapter."""
     return get_adapter_internal(session, adapter_id)
diff --git a/compass/db/api/cluster.py b/compass/db/api/cluster.py
index dadce049..8b8fff33 100644
--- a/compass/db/api/cluster.py
+++ b/compass/db/api/cluster.py
@@ -154,7 +154,7 @@ UPDATED_CLUSTERHOST_LOG_FIELDS = [
     permission.PERMISSION_LIST_CLUSTERS
 )
 @utils.wrap_to_dict(RESP_FIELDS)
-def list_clusters(session, lister, **filters):
+def list_clusters(lister, session=None, **filters):
     """List clusters."""
     return utils.list_db_objects(
         session, models.Cluster, **filters
@@ -168,8 +168,8 @@ def list_clusters(session, lister, **filters):
 )
 @utils.wrap_to_dict(RESP_FIELDS)
 def get_cluster(
-    session, getter, cluster_id,
-    exception_when_missing=True, **kwargs
+    getter, cluster_id,
+    exception_when_missing=True, session=None, **kwargs
 ):
     """Get cluster info."""
     return utils.get_db_object(
@@ -243,9 +243,9 @@ def is_cluster_editable(
 )
 @utils.wrap_to_dict(RESP_FIELDS)
 def add_cluster(
-    session, creator,
+    creator,
     exception_when_existing=True,
-    name=None, **kwargs
+    name=None, session=None, **kwargs
 ):
     """Create a cluster."""
     return utils.add_db_object(
@@ -265,7 +265,7 @@ def add_cluster(
     permission.PERMISSION_ADD_CLUSTER
 )
 @utils.wrap_to_dict(RESP_FIELDS)
-def update_cluster(session, updater, cluster_id, **kwargs):
+def update_cluster(updater, cluster_id, session=None, **kwargs):
     """Update a cluster."""
     cluster = utils.get_db_object(
         session, models.Cluster, id=cluster_id
@@ -301,9 +301,9 @@ def update_cluster(session, updater, cluster_id, **kwargs):
     hosts=RESP_CLUSTERHOST_FIELDS
 )
 def del_cluster(
-    session, deleter, cluster_id,
+    deleter, cluster_id,
     force=False, from_database_only=False,
-    delete_underlying_host=False, **kwargs
+    delete_underlying_host=False, session=None, **kwargs
 ):
     """Delete a cluster."""
     cluster = utils.get_db_object(
@@ -371,7 +371,7 @@ def del_cluster(
     permission.PERMISSION_LIST_CLUSTER_CONFIG
 )
 @utils.wrap_to_dict(RESP_CONFIG_FIELDS)
-def get_cluster_config(session, getter, cluster_id, **kwargs):
+def get_cluster_config(getter, cluster_id, session=None, **kwargs):
     """Get cluster config."""
     return utils.get_db_object(
         session, models.Cluster, id=cluster_id
@@ -384,7 +384,7 @@ def get_cluster_config(session, getter, cluster_id, **kwargs):
     permission.PERMISSION_LIST_CLUSTER_CONFIG
 )
 @utils.wrap_to_dict(RESP_DEPLOYED_CONFIG_FIELDS)
-def get_cluster_deployed_config(session, getter, cluster_id, **kwargs):
+def get_cluster_deployed_config(getter, cluster_id, session=None, **kwargs):
     """Get cluster deployed config."""
     return utils.get_db_object(
         session, models.Cluster, id=cluster_id
@@ -397,7 +397,7 @@ def get_cluster_deployed_config(session, getter, cluster_id, **kwargs):
     permission.PERMISSION_LIST_METADATAS
 )
 @utils.wrap_to_dict(RESP_METADATA_FIELDS)
-def get_cluster_metadata(session, getter, cluster_id, **kwargs):
+def get_cluster_metadata(getter, cluster_id, session=None, **kwargs):
     """Get cluster metadata."""
     cluster = utils.get_db_object(
         session, models.Cluster, id=cluster_id
@@ -418,9 +418,6 @@ def get_cluster_metadata(session, getter, cluster_id, **kwargs):
     return metadatas
 
 
-@user_api.check_user_permission_in_session(
-    permission.PERMISSION_ADD_CLUSTER_CONFIG
-)
 @utils.wrap_to_dict(RESP_CONFIG_FIELDS)
 def _update_cluster_config(session, updater, cluster, **kwargs):
     """Update a cluster config."""
@@ -444,7 +441,7 @@ def _update_cluster_config(session, updater, cluster, **kwargs):
 )
 @utils.wrap_to_dict(RESP_DEPLOYED_CONFIG_FIELDS)
 def update_cluster_deployed_config(
-    session, updater, cluster_id, **kwargs
+    updater, cluster_id, session=None, **kwargs
 ):
     """Update cluster deployed config."""
     cluster = utils.get_db_object(
@@ -466,7 +463,10 @@ def update_cluster_deployed_config(
     ignore_support_keys=IGNORE_FIELDS
 )
 @database.run_in_session()
-def update_cluster_config(session, updater, cluster_id, **kwargs):
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_ADD_CLUSTER_CONFIG
+)
+def update_cluster_config(updater, cluster_id, session=None, **kwargs):
     """Update cluster config."""
     cluster = utils.get_db_object(
         session, models.Cluster, id=cluster_id
@@ -507,7 +507,10 @@ def update_cluster_config(session, updater, cluster_id, **kwargs):
     ignore_support_keys=IGNORE_FIELDS
 )
 @database.run_in_session()
-def patch_cluster_config(session, updater, cluster_id, **kwargs):
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_ADD_CLUSTER_CONFIG
+)
+def patch_cluster_config(updater, cluster_id, session=None, **kwargs):
     """patch cluster config."""
     cluster = utils.get_db_object(
         session, models.Cluster, id=cluster_id
@@ -543,7 +546,7 @@ def patch_cluster_config(session, updater, cluster_id, **kwargs):
     permission.PERMISSION_DEL_CLUSTER_CONFIG
 )
 @utils.wrap_to_dict(RESP_CONFIG_FIELDS)
-def del_cluster_config(session, deleter, cluster_id):
+def del_cluster_config(deleter, cluster_id, session=None):
     """Delete a cluster config."""
     cluster = utils.get_db_object(
         session, models.Cluster, id=cluster_id
@@ -669,7 +672,7 @@ def _set_clusterhosts(session, cluster, machines):
     permission.PERMISSION_LIST_CLUSTERHOSTS
 )
 @utils.wrap_to_dict(RESP_CLUSTERHOST_FIELDS)
-def list_cluster_hosts(session, lister, cluster_id, **filters):
+def list_cluster_hosts(lister, cluster_id, session=None, **filters):
     """Get cluster host info."""
     return utils.list_db_objects(
         session, models.ClusterHost, cluster_id=cluster_id,
@@ -683,7 +686,7 @@ def list_cluster_hosts(session, lister, cluster_id, **filters):
     permission.PERMISSION_LIST_CLUSTERHOSTS
 )
 @utils.wrap_to_dict(RESP_CLUSTERHOST_FIELDS)
-def list_clusterhosts(session, lister, **filters):
+def list_clusterhosts(lister, session=None, **filters):
     """Get cluster host info."""
     return utils.list_db_objects(
         session, models.ClusterHost, **filters
@@ -697,8 +700,8 @@ def list_clusterhosts(session, lister, **filters):
 )
 @utils.wrap_to_dict(RESP_CLUSTERHOST_FIELDS)
 def get_cluster_host(
-    session, getter, cluster_id, host_id,
-    exception_when_missing=True, **kwargs
+    getter, cluster_id, host_id,
+    exception_when_missing=True, session=None, **kwargs
 ):
     """Get clusterhost info."""
     return utils.get_db_object(
@@ -715,8 +718,8 @@ def get_cluster_host(
 )
 @utils.wrap_to_dict(RESP_CLUSTERHOST_FIELDS)
 def get_clusterhost(
-    session, getter, clusterhost_id,
-    exception_when_missing=True, **kwargs
+    getter, clusterhost_id,
+    exception_when_missing=True, session=None, **kwargs
 ):
     """Get clusterhost info."""
     return utils.get_db_object(
@@ -732,8 +735,8 @@ def get_clusterhost(
 )
 @utils.wrap_to_dict(RESP_CLUSTERHOST_FIELDS)
 def add_cluster_host(
-    session, creator, cluster_id,
-    exception_when_existing=True, **kwargs
+    creator, cluster_id,
+    exception_when_existing=True, session=None, **kwargs
 ):
     """Add cluster host."""
     cluster = utils.get_db_object(
@@ -746,9 +749,6 @@ def add_cluster_host(
     )
 
 
-@user_api.check_user_permission_in_session(
-    permission.PERMISSION_UPDATE_CLUSTER_HOSTS
-)
 @utils.wrap_to_dict(RESP_CLUSTERHOST_FIELDS)
 def _update_clusterhost(session, updater, clusterhost, **kwargs):
     clusterhost_dict = {}
@@ -835,9 +835,12 @@ def _update_clusterhost(session, updater, clusterhost, **kwargs):
     ignore_support_keys=IGNORE_FIELDS
 )
 @database.run_in_session()
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_UPDATE_CLUSTER_HOSTS
+)
 def update_cluster_host(
-    session, updater, cluster_id, host_id,
-    **kwargs
+    updater, cluster_id, host_id,
+    session=None, **kwargs
 ):
     """Update cluster host."""
     clusterhost = utils.get_db_object(
@@ -851,9 +854,12 @@ def update_cluster_host(
     ignore_support_keys=IGNORE_FIELDS
 )
 @database.run_in_session()
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_UPDATE_CLUSTER_HOSTS
+)
 def update_clusterhost(
-    session, updater, clusterhost_id,
-    **kwargs
+    updater, clusterhost_id,
+    session=None, **kwargs
 ):
     """Update cluster host."""
     clusterhost = utils.get_db_object(
@@ -870,8 +876,11 @@ def update_clusterhost(
     ignore_support_keys=IGNORE_FIELDS
 )
 @database.run_in_session()
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_UPDATE_CLUSTER_HOSTS
+)
 def patch_cluster_host(
-    session, updater, cluster_id, host_id,
+    updater, cluster_id, host_id, session=None,
     **kwargs
 ):
     """Update cluster host."""
@@ -889,8 +898,11 @@ def patch_cluster_host(
     ignore_support_keys=IGNORE_FIELDS
 )
 @database.run_in_session()
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_UPDATE_CLUSTER_HOSTS
+)
 def patch_clusterhost(
-    session, updater, clusterhost_id,
+    updater, clusterhost_id, session=None,
     **kwargs
 ):
     """Update cluster host."""
@@ -910,10 +922,10 @@ def patch_clusterhost(
     host=RESP_CLUSTERHOST_FIELDS
 )
 def del_cluster_host(
-    session, deleter, cluster_id, host_id,
+    deleter, cluster_id, host_id,
     force=False, from_database_only=False,
     delete_underlying_host=False,
-    **kwargs
+    session=None, **kwargs
 ):
     """Delete cluster host."""
     clusterhost = utils.get_db_object(
@@ -978,10 +990,10 @@ def del_cluster_host(
     host=RESP_CLUSTERHOST_FIELDS
 )
 def del_clusterhost(
-    session, deleter, clusterhost_id,
+    deleter, clusterhost_id,
     force=False, from_database_only=False,
     delete_underlying_host=False,
-    **kwargs
+    session=None, **kwargs
 ):
     """Delete cluster host."""
     clusterhost = utils.get_db_object(
@@ -1039,7 +1051,10 @@ def del_clusterhost(
     permission.PERMISSION_LIST_CLUSTERHOST_CONFIG
 )
 @utils.wrap_to_dict(RESP_CLUSTERHOST_CONFIG_FIELDS)
-def get_cluster_host_config(session, getter, cluster_id, host_id, **kwargs):
+def get_cluster_host_config(
+        getter, cluster_id,
+        host_id, session=None, **kwargs
+):
     """Get clusterhost config."""
     return utils.get_db_object(
         session, models.ClusterHost,
@@ -1054,7 +1069,7 @@ def get_cluster_host_config(session, getter, cluster_id, host_id, **kwargs):
 )
 @utils.wrap_to_dict(RESP_CLUSTERHOST_DEPLOYED_CONFIG_FIELDS)
 def get_cluster_host_deployed_config(
-    session, getter, cluster_id, host_id, **kwargs
+    getter, cluster_id, host_id, session=None, **kwargs
 ):
     """Get clusterhost deployed config."""
     return utils.get_db_object(
@@ -1069,7 +1084,7 @@ def get_cluster_host_deployed_config(
     permission.PERMISSION_LIST_CLUSTERHOST_CONFIG
 )
 @utils.wrap_to_dict(RESP_CLUSTERHOST_CONFIG_FIELDS)
-def get_clusterhost_config(session, getter, clusterhost_id, **kwargs):
+def get_clusterhost_config(getter, clusterhost_id, session=None, **kwargs):
     """Get clusterhost config."""
     return utils.get_db_object(
         session, models.ClusterHost, clusterhost_id=clusterhost_id
@@ -1082,16 +1097,16 @@ def get_clusterhost_config(session, getter, clusterhost_id, **kwargs):
     permission.PERMISSION_LIST_CLUSTERHOST_CONFIG
 )
 @utils.wrap_to_dict(RESP_CLUSTERHOST_DEPLOYED_CONFIG_FIELDS)
-def get_clusterhost_deployed_config(session, getter, clusterhost_id, **kwargs):
+def get_clusterhost_deployed_config(
+    getter, clusterhost_id,
+    session=None, **kwargs
+):
     """Get clusterhost deployed config."""
     return utils.get_db_object(
         session, models.ClusterHost, clusterhost_id=clusterhost_id
     )
 
 
-@user_api.check_user_permission_in_session(
-    permission.PERMISSION_ADD_CLUSTERHOST_CONFIG
-)
 @utils.wrap_to_dict(RESP_CLUSTERHOST_CONFIG_FIELDS)
 def _update_clusterhost_config(session, updater, clusterhost, **kwargs):
     from compass.db.api import host as host_api
@@ -1132,9 +1147,6 @@ def _update_clusterhost_config(session, updater, clusterhost, **kwargs):
     )
 
 
-@user_api.check_user_permission_in_session(
-    permission.PERMISSION_ADD_CLUSTERHOST_CONFIG
-)
 @utils.wrap_to_dict(RESP_CLUSTERHOST_DEPLOYED_CONFIG_FIELDS)
 def _update_clusterhost_deployed_config(
     session, updater, clusterhost, **kwargs
@@ -1179,8 +1191,11 @@ def _update_clusterhost_deployed_config(
     package_config='put_package_config'
 )
 @database.run_in_session()
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_ADD_CLUSTERHOST_CONFIG
+)
 def update_cluster_host_config(
-    session, updater, cluster_id, host_id, **kwargs
+    updater, cluster_id, host_id, session=None, **kwargs
 ):
     """Update clusterhost config."""
     clusterhost = utils.get_db_object(
@@ -1197,8 +1212,11 @@ def update_cluster_host_config(
     package_config='deployed_package_config'
 )
 @database.run_in_session()
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_ADD_CLUSTERHOST_CONFIG
+)
 def update_cluster_host_deployed_config(
-    session, updater, cluster_id, host_id, **kwargs
+    updater, cluster_id, host_id, session=None, **kwargs
 ):
     """Update clusterhost deployed config."""
     clusterhost = utils.get_db_object(
@@ -1215,8 +1233,11 @@ def update_cluster_host_deployed_config(
     package_config='put_package_config'
 )
 @database.run_in_session()
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_ADD_CLUSTERHOST_CONFIG
+)
 def update_clusterhost_config(
-    session, updater, clusterhost_id, **kwargs
+    updater, clusterhost_id, session=None, **kwargs
 ):
     """Update clusterhost config."""
     clusterhost = utils.get_db_object(
@@ -1232,8 +1253,11 @@ def update_clusterhost_config(
     package_config='deployed_package_config'
 )
 @database.run_in_session()
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_ADD_CLUSTERHOST_CONFIG
+)
 def update_clusterhost_deployed_config(
-    session, updater, clusterhost_id, **kwargs
+    updater, clusterhost_id, session=None, **kwargs
 ):
     """Update clusterhost deployed config."""
     clusterhost = utils.get_db_object(
@@ -1244,9 +1268,6 @@ def update_clusterhost_deployed_config(
     )
 
 
-@user_api.check_user_permission_in_session(
-    permission.PERMISSION_ADD_CLUSTERHOST_CONFIG
-)
 @utils.wrap_to_dict(RESP_CLUSTERHOST_CONFIG_FIELDS)
 def _patch_clusterhost_config(session, updater, clusterhost, **kwargs):
     from compass.db.api import host as host_api
@@ -1291,8 +1312,11 @@ def _patch_clusterhost_config(session, updater, clusterhost, **kwargs):
     package_config='patched_package_config'
 )
 @database.run_in_session()
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_ADD_CLUSTERHOST_CONFIG
+)
 def patch_cluster_host_config(
-    session, updater, cluster_id, host_id, **kwargs
+    updater, cluster_id, host_id, session=None, **kwargs
 ):
     """patch clusterhost config."""
     clusterhost = utils.get_db_object(
@@ -1309,8 +1333,11 @@ def patch_cluster_host_config(
     package_config='patched_package_config'
 )
 @database.run_in_session()
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_ADD_CLUSTERHOST_CONFIG
+)
 def patch_clusterhost_config(
-    session, updater, clusterhost_id, **kwargs
+    updater, clusterhost_id, session=None, **kwargs
 ):
     """patch clusterhost config."""
     clusterhost = utils.get_db_object(
@@ -1321,9 +1348,6 @@ def patch_clusterhost_config(
     )
 
 
-@user_api.check_user_permission_in_session(
-    permission.PERMISSION_DEL_CLUSTERHOST_CONFIG
-)
 @utils.wrap_to_dict(RESP_CLUSTERHOST_CONFIG_FIELDS)
 def _delete_clusterhost_config(
     session, deleter, clusterhost
@@ -1360,8 +1384,11 @@ def _delete_clusterhost_config(
 
 @utils.supported_filters([])
 @database.run_in_session()
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_DEL_CLUSTERHOST_CONFIG
+)
 def delete_cluster_host_config(
-    session, deleter, cluster_id, host_id
+    deleter, cluster_id, host_id, session=None
 ):
     """Delete a clusterhost config."""
     clusterhost = utils.get_db_object(
@@ -1379,7 +1406,7 @@ def delete_cluster_host_config(
     permission.PERMISSION_DEL_CLUSTERHOST_CONFIG
 )
 @utils.wrap_to_dict(RESP_CLUSTERHOST_CONFIG_FIELDS)
-def delete_clusterhost_config(session, deleter, clusterhost_id):
+def delete_clusterhost_config(deleter, clusterhost_id, session=None):
     """Delet a clusterhost config."""
     clusterhost = utils.get_db_object(
         session, models.ClusterHost, clusterhost_id=clusterhost_id
@@ -1401,8 +1428,8 @@ def delete_clusterhost_config(session, deleter, clusterhost_id):
     hosts=RESP_CLUSTERHOST_FIELDS
 )
 def update_cluster_hosts(
-    session, updater, cluster_id, add_hosts={}, set_hosts=None,
-    remove_hosts={}
+    updater, cluster_id, add_hosts={}, set_hosts=None,
+    remove_hosts={}, session=None
 ):
     """Update cluster hosts."""
     cluster = utils.get_db_object(
@@ -1487,7 +1514,7 @@ def validate_cluster(session, cluster):
     cluster=RESP_CONFIG_FIELDS,
     hosts=RESP_CLUSTERHOST_CONFIG_FIELDS
 )
-def review_cluster(session, reviewer, cluster_id, review={}, **kwargs):
+def review_cluster(reviewer, cluster_id, review={}, session=None, **kwargs):
     """review cluster."""
     from compass.db.api import host as host_api
     cluster = utils.get_db_object(
@@ -1589,7 +1616,7 @@ def review_cluster(session, reviewer, cluster_id, review={}, **kwargs):
     hosts=RESP_CLUSTERHOST_FIELDS
 )
 def deploy_cluster(
-    session, deployer, cluster_id, deploy={}, **kwargs
+    deployer, cluster_id, deploy={}, session=None, **kwargs
 ):
     """deploy cluster."""
     from compass.db.api import host as host_api
@@ -1645,7 +1672,7 @@ def deploy_cluster(
     permission.PERMISSION_GET_CLUSTER_STATE
 )
 @utils.wrap_to_dict(RESP_STATE_FIELDS)
-def get_cluster_state(session, getter, cluster_id, **kwargs):
+def get_cluster_state(getter, cluster_id, session=None, **kwargs):
     """Get cluster state info."""
     return utils.get_db_object(
         session, models.Cluster, id=cluster_id
@@ -1659,7 +1686,7 @@ def get_cluster_state(session, getter, cluster_id, **kwargs):
 )
 @utils.wrap_to_dict(RESP_CLUSTERHOST_STATE_FIELDS)
 def get_cluster_host_state(
-    session, getter, cluster_id, host_id, **kwargs
+    getter, cluster_id, host_id, session=None, **kwargs
 ):
     """Get clusterhost state info."""
     return utils.get_db_object(
@@ -1675,7 +1702,7 @@ def get_cluster_host_state(
 )
 @utils.wrap_to_dict(RESP_CLUSTERHOST_STATE_FIELDS)
 def get_cluster_host_self_state(
-    session, getter, cluster_id, host_id, **kwargs
+    getter, cluster_id, host_id, session=None, **kwargs
 ):
     """Get clusterhost state info."""
     clusterhost = utils.get_db_object(
@@ -1695,7 +1722,7 @@ def get_cluster_host_self_state(
 )
 @utils.wrap_to_dict(RESP_CLUSTERHOST_STATE_FIELDS)
 def get_clusterhost_state(
-    session, getter, clusterhost_id, **kwargs
+    getter, clusterhost_id, session=None, **kwargs
 ):
     """Get clusterhost state info."""
     return utils.get_db_object(
@@ -1711,7 +1738,7 @@ def get_clusterhost_state(
 )
 @utils.wrap_to_dict(RESP_CLUSTERHOST_STATE_FIELDS)
 def get_clusterhost_self_state(
-    session, getter, clusterhost_id, **kwargs
+    getter, clusterhost_id, session=None, **kwargs
 ):
     """Get clusterhost state info."""
     return utils.get_db_object(
@@ -1730,7 +1757,7 @@ def get_clusterhost_self_state(
 )
 @utils.wrap_to_dict(RESP_CLUSTERHOST_STATE_FIELDS)
 def update_cluster_host_state(
-    session, updater, cluster_id, host_id, **kwargs
+    updater, cluster_id, host_id, session=None, **kwargs
 ):
     """Update a clusterhost state."""
     clusterhost = utils.get_db_object(
@@ -1751,7 +1778,7 @@ def update_cluster_host_state(
 )
 @utils.wrap_to_dict(RESP_CLUSTERHOST_STATE_FIELDS)
 def update_clusterhost_state(
-    session, updater, clusterhost_id, **kwargs
+    updater, clusterhost_id, session=None, **kwargs
 ):
     """Update a clusterhost state."""
     clusterhost = utils.get_db_object(
@@ -1772,7 +1799,7 @@ def update_clusterhost_state(
 )
 @utils.wrap_to_dict(RESP_STATE_FIELDS)
 def update_cluster_state(
-    session, updater, cluster_id, **kwargs
+    updater, cluster_id, session=None, **kwargs
 ):
     """Update a cluster state."""
     cluster = utils.get_db_object(
@@ -1786,7 +1813,7 @@ def update_cluster_state(
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_CLUSTERHOST_LOG_FIELDS)
 def get_cluster_host_log_histories(
-    session, getter, cluster_id, host_id, **kwargs
+    getter, cluster_id, host_id, session=None, **kwargs
 ):
     """Get clusterhost log history."""
     return utils.list_db_objects(
@@ -1798,7 +1825,10 @@ def get_cluster_host_log_histories(
 @utils.supported_filters([])
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_CLUSTERHOST_LOG_FIELDS)
-def get_clusterhost_log_histories(session, getter, clusterhost_id, **kwargs):
+def get_clusterhost_log_histories(
+    getter, clusterhost_id,
+    session=None, **kwargs
+):
     """Get clusterhost log history."""
     return utils.list_db_objects(
         session, models.ClusterHostLogHistory, clusterhost_id=clusterhost_id
@@ -1809,7 +1839,7 @@ def get_clusterhost_log_histories(session, getter, clusterhost_id, **kwargs):
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_CLUSTERHOST_LOG_FIELDS)
 def get_cluster_host_log_history(
-    session, getter, cluster_id, host_id, filename, **kwargs
+    getter, cluster_id, host_id, filename, session=None, **kwargs
 ):
     """Get clusterhost log history."""
     return utils.get_db_object(
@@ -1822,7 +1852,7 @@ def get_cluster_host_log_history(
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_CLUSTERHOST_LOG_FIELDS)
 def get_clusterhost_log_history(
-    session, getter, clusterhost_id, filename, **kwargs
+    getter, clusterhost_id, filename, session=None, **kwargs
 ):
     """Get host log history."""
     return utils.get_db_object(
@@ -1838,7 +1868,7 @@ def get_clusterhost_log_history(
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_CLUSTERHOST_LOG_FIELDS)
 def update_cluster_host_log_history(
-    session, updater, cluster_id, host_id, filename, **kwargs
+    updater, cluster_id, host_id, filename, session=None, **kwargs
 ):
     """Update a host log history."""
     cluster_host_log_history = utils.get_db_object(
@@ -1855,7 +1885,7 @@ def update_cluster_host_log_history(
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_CLUSTERHOST_LOG_FIELDS)
 def update_clusterhost_log_history(
-    session, updater, clusterhost_id, filename, **kwargs
+    updater, clusterhost_id, filename, session=None, **kwargs
 ):
     """Update a host log history."""
     clusterhost_log_history = utils.get_db_object(
@@ -1873,8 +1903,8 @@ def update_clusterhost_log_history(
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_CLUSTERHOST_LOG_FIELDS)
 def add_clusterhost_log_history(
-    session, creator, clusterhost_id, exception_when_existing=False,
-    filename=None, **kwargs
+    creator, clusterhost_id, exception_when_existing=False,
+    filename=None, session=None, **kwargs
 ):
     """add a host log history."""
     return utils.add_db_object(
@@ -1891,8 +1921,8 @@ def add_clusterhost_log_history(
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_CLUSTERHOST_LOG_FIELDS)
 def add_cluster_host_log_history(
-    session, creator, cluster_id, host_id, exception_when_existing=False,
-    filename=None, **kwargs
+    creator, cluster_id, host_id, exception_when_existing=False,
+    filename=None, session=None, **kwargs
 ):
     """add a host log history."""
     clusterhost = utils.get_db_object(
diff --git a/compass/db/api/database.py b/compass/db/api/database.py
index fbc9ca2b..fa8ad294 100644
--- a/compass/db/api/database.py
+++ b/compass/db/api/database.py
@@ -149,8 +149,14 @@ def run_in_session():
     def decorator(func):
         @functools.wraps(func)
         def wrapper(*args, **kwargs):
-            with session() as my_session:
-                return func(my_session, *args, **kwargs)
+            if args is not () and 'session' in str(args[-1]):
+                    return func(*args, **kwargs)
+            elif 'session' in kwargs.keys():
+                return func(*args, **kwargs)
+            else:
+                with session() as my_session:
+                    kwargs['session'] = my_session
+                    return func(*args, **kwargs)
         return wrapper
     return decorator
 
@@ -289,24 +295,24 @@ def _update_others(other_session):
 
 
 @run_in_session()
-def create_db(my_session):
+def create_db(session):
     """Create database."""
     models.BASE.metadata.create_all(bind=ENGINE)
-    _setup_permission_table(my_session)
-    _setup_user_table(my_session)
-    _setup_switch_table(my_session)
-    _setup_os_installers(my_session)
-    _setup_package_installers(my_session)
-    _setup_oses(my_session)
-    _setup_distributed_systems(my_session)
-    _setup_adapters(my_session)
-    _setup_adapter_roles(my_session)
-    _setup_adapter_flavors(my_session)
-    _setup_os_fields(my_session)
-    _setup_package_fields(my_session)
-    _setup_os_metadatas(my_session)
-    _setup_package_metadatas(my_session)
-    _update_others(my_session)
+    _setup_permission_table(session)
+    _setup_user_table(session)
+    _setup_switch_table(session)
+    _setup_os_installers(session)
+    _setup_package_installers(session)
+    _setup_oses(session)
+    _setup_distributed_systems(session)
+    _setup_adapters(session)
+    _setup_adapter_roles(session)
+    _setup_adapter_flavors(session)
+    _setup_os_fields(session)
+    _setup_package_fields(session)
+    _setup_os_metadatas(session)
+    _setup_package_metadatas(session)
+    _update_others(session)
 
 
 def drop_db():
diff --git a/compass/db/api/host.py b/compass/db/api/host.py
index 19c43cab..b5b8d543 100644
--- a/compass/db/api/host.py
+++ b/compass/db/api/host.py
@@ -107,7 +107,7 @@ UPDATED_LOG_FIELDS = [
     permission.PERMISSION_LIST_HOSTS
 )
 @utils.wrap_to_dict(RESP_FIELDS)
-def list_hosts(session, lister, **filters):
+def list_hosts(lister, session=None, **filters):
     """List hosts."""
     return utils.list_db_objects(
         session, models.Host, **filters
@@ -128,7 +128,7 @@ def list_hosts(session, lister, **filters):
     os_id=utils.general_filter_callback
 )
 @utils.wrap_to_dict(RESP_FIELDS)
-def list_machines_or_hosts(session, lister, **filters):
+def list_machines_or_hosts(lister, session=None, **filters):
     """List hosts."""
     machines = utils.list_db_objects(
         session, models.Machine, **filters
@@ -150,8 +150,8 @@ def list_machines_or_hosts(session, lister, **filters):
 )
 @utils.wrap_to_dict(RESP_FIELDS)
 def get_host(
-    session, getter, host_id,
-    exception_when_missing=True, **kwargs
+    getter, host_id,
+    exception_when_missing=True, session=None, **kwargs
 ):
     """get host info."""
     return utils.get_db_object(
@@ -167,8 +167,8 @@ def get_host(
 )
 @utils.wrap_to_dict(RESP_FIELDS)
 def get_machine_or_host(
-    session, getter, host_id,
-    exception_when_missing=True, **kwargs
+    getter, host_id,
+    exception_when_missing=True, session=None, **kwargs
 ):
     """get host info."""
     machine = utils.get_db_object(
@@ -190,7 +190,7 @@ def get_machine_or_host(
     permission.PERMISSION_LIST_HOST_CLUSTERS
 )
 @utils.wrap_to_dict(RESP_CLUSTER_FIELDS)
-def get_host_clusters(session, getter, host_id, **kwargs):
+def get_host_clusters(getter, host_id, session=None, **kwargs):
     """get host clusters."""
     host = utils.get_db_object(
         session, models.Host, id=host_id
@@ -303,7 +303,7 @@ def _update_host(session, updater, host_id, **kwargs):
 @user_api.check_user_permission_in_session(
     permission.PERMISSION_UPDATE_HOST
 )
-def update_host(session, updater, host_id, **kwargs):
+def update_host(updater, host_id, session=None, **kwargs):
     """Update a host."""
     return _update_host(session, updater, host_id=host_id, **kwargs)
 
@@ -312,7 +312,7 @@ def update_host(session, updater, host_id, **kwargs):
 @user_api.check_user_permission_in_session(
     permission.PERMISSION_UPDATE_HOST
 )
-def update_hosts(session, updater, data=[]):
+def update_hosts(updater, data=[], session=None):
     hosts = []
     for host_data in data:
         hosts.append(_update_host(session, updater, **host_data))
@@ -329,8 +329,8 @@ def update_hosts(session, updater, data=[]):
     host=RESP_FIELDS
 )
 def del_host(
-    session, deleter, host_id,
-    force=False, from_database_only=False, **kwargs
+    deleter, host_id,
+    force=False, from_database_only=False, session=None, **kwargs
 ):
     """Delete a host."""
     from compass.db.api import cluster as cluster_api
@@ -378,7 +378,7 @@ def del_host(
     permission.PERMISSION_LIST_HOST_CONFIG
 )
 @utils.wrap_to_dict(RESP_CONFIG_FIELDS)
-def get_host_config(session, getter, host_id, **kwargs):
+def get_host_config(getter, host_id, session=None, **kwargs):
     """Get host config."""
     return utils.get_db_object(
         session, models.Host, id=host_id
@@ -391,7 +391,7 @@ def get_host_config(session, getter, host_id, **kwargs):
     permission.PERMISSION_LIST_HOST_CONFIG
 )
 @utils.wrap_to_dict(RESP_DEPLOYED_CONFIG_FIELDS)
-def get_host_deployed_config(session, getter, host_id, **kwargs):
+def get_host_deployed_config(getter, host_id, session=None, **kwargs):
     """Get host deployed config."""
     return utils.get_db_object(
         session, models.Host, id=host_id
@@ -410,7 +410,7 @@ def get_host_deployed_config(session, getter, host_id, **kwargs):
     permission.PERMISSION_ADD_HOST_CONFIG
 )
 @utils.wrap_to_dict(RESP_CONFIG_FIELDS)
-def update_host_deployed_config(session, updater, host_id, **kwargs):
+def update_host_deployed_config(updater, host_id, session=None, **kwargs):
     """Update host deployed config."""
     host = utils.get_db_object(
         session, models.Host, id=host_id
@@ -420,9 +420,6 @@ def update_host_deployed_config(session, updater, host_id, **kwargs):
     return utils.update_db_object(session, host, **kwargs)
 
 
-@user_api.check_user_permission_in_session(
-    permission.PERMISSION_ADD_HOST_CONFIG
-)
 @utils.wrap_to_dict(RESP_CONFIG_FIELDS)
 def _update_host_config(session, updater, host, **kwargs):
     """Update host config."""
@@ -438,7 +435,10 @@ def _update_host_config(session, updater, host, **kwargs):
     ignore_support_keys=IGNORE_FIELDS
 )
 @database.run_in_session()
-def update_host_config(session, updater, host_id, **kwargs):
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_ADD_HOST_CONFIG
+)
+def update_host_config(updater, host_id, session=None, **kwargs):
     host = utils.get_db_object(
         session, models.Host, id=host_id
     )
@@ -469,7 +469,10 @@ def update_host_config(session, updater, host_id, **kwargs):
     ignore_support_keys=IGNORE_FIELDS
 )
 @database.run_in_session()
-def patch_host_config(session, updater, host_id, **kwargs):
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_ADD_HOST_CONFIG
+)
+def patch_host_config(updater, host_id, session=None, **kwargs):
     host = utils.get_db_object(
         session, models.Host, id=host_id
     )
@@ -498,7 +501,7 @@ def patch_host_config(session, updater, host_id, **kwargs):
     permission.PERMISSION_DEL_HOST_CONFIG
 )
 @utils.wrap_to_dict(RESP_CONFIG_FIELDS)
-def del_host_config(session, deleter, host_id):
+def del_host_config(deleter, host_id, session=None):
     """delete a host config."""
     host = utils.get_db_object(
         session, models.Host, id=host_id
@@ -517,7 +520,7 @@ def del_host_config(session, deleter, host_id):
     permission.PERMISSION_LIST_HOST_NETWORKS
 )
 @utils.wrap_to_dict(RESP_NETWORK_FIELDS)
-def list_host_networks(session, lister, host_id, **filters):
+def list_host_networks(lister, host_id, session=None, **filters):
     """Get host networks."""
     return utils.list_db_objects(
         session, models.HostNetwork,
@@ -533,7 +536,7 @@ def list_host_networks(session, lister, host_id, **filters):
     permission.PERMISSION_LIST_HOST_NETWORKS
 )
 @utils.wrap_to_dict(RESP_NETWORK_FIELDS)
-def list_hostnetworks(session, lister, **filters):
+def list_hostnetworks(lister, session=None, **filters):
     """Get host networks."""
     return utils.list_db_objects(
         session, models.HostNetwork, **filters
@@ -547,8 +550,8 @@ def list_hostnetworks(session, lister, **filters):
 )
 @utils.wrap_to_dict(RESP_NETWORK_FIELDS)
 def get_host_network(
-    session, getter, host_id,
-    host_network_id, **kwargs
+    getter, host_id,
+    host_network_id, session=None, **kwargs
 ):
     """Get host network."""
     host_network = utils.get_db_object(
@@ -570,7 +573,7 @@ def get_host_network(
     permission.PERMISSION_LIST_HOST_NETWORKS
 )
 @utils.wrap_to_dict(RESP_NETWORK_FIELDS)
-def get_hostnetwork(session, getter, host_network_id, **kwargs):
+def get_hostnetwork(getter, host_network_id, session=None, **kwargs):
     """Get host network."""
     return utils.get_db_object(
         session, models.HostNetwork,
@@ -623,9 +626,9 @@ def _add_host_network(
     permission.PERMISSION_ADD_HOST_NETWORK
 )
 def add_host_network(
-    session, creator, host_id,
+    creator, host_id,
     exception_when_existing=True,
-    interface=None, **kwargs
+    interface=None, session=None, **kwargs
 ):
     """Create a host network."""
     return _add_host_network(
@@ -639,9 +642,9 @@ def add_host_network(
     permission.PERMISSION_ADD_HOST_NETWORK
 )
 def add_host_networks(
-    session, creator,
+    creator,
     exception_when_existing=False,
-    data=[]
+    data=[], session=None
 ):
     """Create host networks."""
     hosts = []
@@ -672,9 +675,6 @@ def add_host_networks(
     }
 
 
-@user_api.check_user_permission_in_session(
-    permission.PERMISSION_ADD_HOST_NETWORK
-)
 @utils.wrap_to_dict(RESP_NETWORK_FIELDS)
 def _update_host_network(
     session, updater, host_network, **kwargs
@@ -720,8 +720,11 @@ def _update_host_network(
     ip=utils.check_ip
 )
 @database.run_in_session()
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_ADD_HOST_NETWORK
+)
 def update_host_network(
-    session, updater, host_id, host_network_id, **kwargs
+    updater, host_id, host_network_id, session=None, **kwargs
 ):
     """Update a host network."""
     host_network = utils.get_db_object(
@@ -747,7 +750,10 @@ def update_host_network(
     ip=utils.check_ip
 )
 @database.run_in_session()
-def update_hostnetwork(session, updater, host_network_id, **kwargs):
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_ADD_HOST_NETWORK
+)
+def update_hostnetwork(updater, host_network_id, session=None, **kwargs):
     """Update a host network."""
     host_network = utils.get_db_object(
         session, models.HostNetwork, id=host_network_id
@@ -763,7 +769,10 @@ def update_hostnetwork(session, updater, host_network_id, **kwargs):
     permission.PERMISSION_DEL_HOST_NETWORK
 )
 @utils.wrap_to_dict(RESP_NETWORK_FIELDS)
-def del_host_network(session, deleter, host_id, host_network_id, **kwargs):
+def del_host_network(
+    deleter, host_id, host_network_id,
+    session=None, **kwargs
+):
     """Delete a host network."""
     host_network = utils.get_db_object(
         session, models.HostNetwork,
@@ -785,7 +794,7 @@ def del_host_network(session, deleter, host_id, host_network_id, **kwargs):
     permission.PERMISSION_DEL_HOST_NETWORK
 )
 @utils.wrap_to_dict(RESP_NETWORK_FIELDS)
-def del_hostnetwork(session, deleter, host_network_id, **kwargs):
+def del_hostnetwork(deleter, host_network_id, session=None, **kwargs):
     """Delete a host network."""
     host_network = utils.get_db_object(
         session, models.HostNetwork, id=host_network_id
@@ -800,7 +809,7 @@ def del_hostnetwork(session, deleter, host_network_id, **kwargs):
     permission.PERMISSION_GET_HOST_STATE
 )
 @utils.wrap_to_dict(RESP_STATE_FIELDS)
-def get_host_state(session, getter, host_id, **kwargs):
+def get_host_state(getter, host_id, session=None, **kwargs):
     """Get host state info."""
     return utils.get_db_object(
         session, models.Host, id=host_id
@@ -816,7 +825,7 @@ def get_host_state(session, getter, host_id, **kwargs):
     permission.PERMISSION_UPDATE_HOST_STATE
 )
 @utils.wrap_to_dict(RESP_STATE_FIELDS)
-def update_host_state(session, updater, host_id, **kwargs):
+def update_host_state(updater, host_id, session=None, **kwargs):
     """Update a host state."""
     host = utils.get_db_object(
         session, models.Host, id=host_id
@@ -828,7 +837,7 @@ def update_host_state(session, updater, host_id, **kwargs):
 @utils.supported_filters([])
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_LOG_FIELDS)
-def get_host_log_histories(session, getter, host_id, **kwargs):
+def get_host_log_histories(getter, host_id, session=None, **kwargs):
     """Get host log history."""
     return utils.list_db_objects(
         session, models.HostLogHistory, id=host_id
@@ -838,7 +847,7 @@ def get_host_log_histories(session, getter, host_id, **kwargs):
 @utils.supported_filters([])
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_LOG_FIELDS)
-def get_host_log_history(session, getter, host_id, filename, **kwargs):
+def get_host_log_history(getter, host_id, filename, session=None, **kwargs):
     """Get host log history."""
     return utils.get_db_object(
         session, models.HostLogHistory, id=host_id, filename=filename
@@ -851,7 +860,10 @@ def get_host_log_history(session, getter, host_id, filename, **kwargs):
 )
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_LOG_FIELDS)
-def update_host_log_history(session, updater, host_id, filename, **kwargs):
+def update_host_log_history(
+    updater, host_id, filename,
+    session=None, **kwargs
+):
     """Update a host log history."""
     host_log_history = utils.get_db_object(
         session, models.HostLogHistory, id=host_id, filename=filename
@@ -867,8 +879,8 @@ def update_host_log_history(session, updater, host_id, filename, **kwargs):
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_LOG_FIELDS)
 def add_host_log_history(
-    session, creator, host_id, exception_when_existing=False,
-    filename=None, **kwargs
+    creator, host_id, exception_when_existing=False,
+    filename=None, session=None, **kwargs
 ):
     """add a host log history."""
     return utils.add_db_object(
@@ -887,7 +899,7 @@ def add_host_log_history(
     host=RESP_CONFIG_FIELDS
 )
 def poweron_host(
-    session, deployer, host_id, poweron={}, **kwargs
+    deployer, host_id, poweron={}, session=None, **kwargs
 ):
     """power on host."""
     from compass.tasks import client as celery_client
@@ -915,7 +927,7 @@ def poweron_host(
     host=RESP_CONFIG_FIELDS
 )
 def poweroff_host(
-    session, deployer, host_id, poweroff={}, **kwargs
+    deployer, host_id, poweroff={}, session=None, **kwargs
 ):
     """power off host."""
     from compass.tasks import client as celery_client
@@ -943,7 +955,7 @@ def poweroff_host(
     host=RESP_CONFIG_FIELDS
 )
 def reset_host(
-    session, deployer, host_id, reset={}, **kwargs
+    deployer, host_id, reset={}, session=None, **kwargs
 ):
     """reset host."""
     from compass.tasks import client as celery_client
diff --git a/compass/db/api/machine.py b/compass/db/api/machine.py
index 8a168344..0920b410 100644
--- a/compass/db/api/machine.py
+++ b/compass/db/api/machine.py
@@ -50,8 +50,8 @@ RESP_DEPLOY_FIELDS = [
 )
 @utils.wrap_to_dict(RESP_FIELDS)
 def get_machine(
-    session, getter, machine_id,
-    exception_when_missing=True,
+    getter, machine_id,
+    exception_when_missing=True, session=None,
     **kwargs
 ):
     """get field dict of a machine."""
@@ -73,16 +73,13 @@ def get_machine(
     location=utils.general_filter_callback
 )
 @utils.wrap_to_dict(RESP_FIELDS)
-def list_machines(session, lister, **filters):
+def list_machines(lister, session=None, **filters):
     """List machines."""
     return utils.list_db_objects(
         session, models.Machine, **filters
     )
 
 
-@user_api.check_user_permission_in_session(
-    permission.PERMISSION_ADD_MACHINE
-)
 @utils.wrap_to_dict(RESP_FIELDS)
 def _update_machine(session, updater, machine_id, **kwargs):
     """Update a machine."""
@@ -96,7 +93,10 @@ def _update_machine(session, updater, machine_id, **kwargs):
 )
 @utils.input_validates(ipmi_credentials=utils.check_ipmi_credentials)
 @database.run_in_session()
-def update_machine(session, updater, machine_id, **kwargs):
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_ADD_MACHINE
+)
+def update_machine(updater, machine_id, session=None, **kwargs):
     return _update_machine(
         session, updater, machine_id, **kwargs
     )
@@ -113,7 +113,7 @@ def update_machine(session, updater, machine_id, **kwargs):
 )
 @database.run_in_session()
 @utils.output_validates(ipmi_credentials=utils.check_ipmi_credentials)
-def patch_machine(session, updater, machine_id, **kwargs):
+def patch_machine(updater, machine_id, session=None, **kwargs):
     return _update_machine(
         session, updater, machine_id, **kwargs
     )
@@ -125,7 +125,7 @@ def patch_machine(session, updater, machine_id, **kwargs):
     permission.PERMISSION_DEL_MACHINE
 )
 @utils.wrap_to_dict(RESP_FIELDS)
-def del_machine(session, deleter, machine_id, **kwargs):
+def del_machine(deleter, machine_id, session=None, **kwargs):
     """Delete a machine."""
     machine = utils.get_db_object(session, models.Machine, id=machine_id)
     if machine.host:
@@ -148,7 +148,7 @@ def del_machine(session, deleter, machine_id, **kwargs):
     machine=RESP_FIELDS
 )
 def poweron_machine(
-    session, deployer, machine_id, poweron={}, **kwargs
+    deployer, machine_id, poweron={}, session=None, **kwargs
 ):
     """power on machine."""
     from compass.tasks import client as celery_client
@@ -175,7 +175,7 @@ def poweron_machine(
     machine=RESP_FIELDS
 )
 def poweroff_machine(
-    session, deployer, machine_id, poweroff={}, **kwargs
+    deployer, machine_id, poweroff={}, session=None, **kwargs
 ):
     """power off machine."""
     from compass.tasks import client as celery_client
@@ -202,7 +202,7 @@ def poweroff_machine(
     machine=RESP_FIELDS
 )
 def reset_machine(
-    session, deployer, machine_id, reset={}, **kwargs
+    deployer, machine_id, reset={}, session=None, **kwargs
 ):
     """reset machine."""
     from compass.tasks import client as celery_client
diff --git a/compass/db/api/metadata_holder.py b/compass/db/api/metadata_holder.py
index 231b4801..f2f395f6 100644
--- a/compass/db/api/metadata_holder.py
+++ b/compass/db/api/metadata_holder.py
@@ -133,7 +133,7 @@ def get_package_metadata_internal(session, adapter_id):
     permission.PERMISSION_LIST_METADATAS
 )
 @utils.wrap_to_dict(RESP_METADATA_FIELDS)
-def get_package_metadata(session, getter, adapter_id, **kwargs):
+def get_package_metadata(getter, adapter_id, session=None, **kwargs):
     return {
         'package_config': get_package_metadata_internal(session, adapter_id)
     }
@@ -158,7 +158,7 @@ def get_os_metadata_internal(session, os_id):
     permission.PERMISSION_LIST_METADATAS
 )
 @utils.wrap_to_dict(RESP_METADATA_FIELDS)
-def get_os_metadata(session, getter, os_id, **kwargs):
+def get_os_metadata(getter, os_id, session=None, **kwargs):
     """get os metadatas."""
     return {'os_config': get_os_metadata_internal(session, os_id)}
 
@@ -169,7 +169,7 @@ def get_os_metadata(session, getter, os_id, **kwargs):
     permission.PERMISSION_LIST_METADATAS
 )
 @utils.wrap_to_dict(RESP_METADATA_FIELDS)
-def get_package_os_metadata(session, getter, adapter_id, os_id, **kwargs):
+def get_package_os_metadata(getter, adapter_id, os_id, session=None, **kwargs):
     from compass.db.api import adapter_holder as adapter_api
     adapter = adapter_api.get_adapter_internal(session, adapter_id)
     os_ids = [os['os_id'] for os in adapter['supported_oses']]
diff --git a/compass/db/api/network.py b/compass/db/api/network.py
index 94f71987..35c51c90 100644
--- a/compass/db/api/network.py
+++ b/compass/db/api/network.py
@@ -51,7 +51,7 @@ def _check_subnet(subnet):
     permission.PERMISSION_LIST_SUBNETS
 )
 @utils.wrap_to_dict(RESP_FIELDS)
-def list_subnets(session, lister, **filters):
+def list_subnets(lister, session=None, **filters):
     """List subnets."""
     return utils.list_db_objects(
         session, models.Subnet, **filters
@@ -65,8 +65,8 @@ def list_subnets(session, lister, **filters):
 )
 @utils.wrap_to_dict(RESP_FIELDS)
 def get_subnet(
-    session, getter, subnet_id,
-    exception_when_missing=True, **kwargs
+    getter, subnet_id,
+    exception_when_missing=True, session=None, **kwargs
 ):
     """Get subnet info."""
     return utils.get_db_object(
@@ -86,8 +86,8 @@ def get_subnet(
 )
 @utils.wrap_to_dict(RESP_FIELDS)
 def add_subnet(
-    session, creator, exception_when_existing=True,
-    subnet=None, **kwargs
+    creator, exception_when_existing=True,
+    subnet=None, session=None, **kwargs
 ):
     """Create a subnet."""
     return utils.add_db_object(
@@ -106,7 +106,7 @@ def add_subnet(
     permission.PERMISSION_ADD_SUBNET
 )
 @utils.wrap_to_dict(RESP_FIELDS)
-def update_subnet(session, updater, subnet_id, **kwargs):
+def update_subnet(updater, subnet_id, session=None, **kwargs):
     """Update a subnet."""
     subnet = utils.get_db_object(
         session, models.Subnet, id=subnet_id
@@ -120,7 +120,7 @@ def update_subnet(session, updater, subnet_id, **kwargs):
     permission.PERMISSION_DEL_SUBNET
 )
 @utils.wrap_to_dict(RESP_FIELDS)
-def del_subnet(session, deleter, subnet_id, **kwargs):
+def del_subnet(deleter, subnet_id, session=None, **kwargs):
     """Delete a subnet."""
     subnet = utils.get_db_object(
         session, models.Subnet, id=subnet_id
diff --git a/compass/db/api/permission.py b/compass/db/api/permission.py
index 4def53c4..59fd8739 100644
--- a/compass/db/api/permission.py
+++ b/compass/db/api/permission.py
@@ -270,7 +270,7 @@ def list_permissions_internal(session, **filters):
 @database.run_in_session()
 @user_api.check_user_permission_in_session(PERMISSION_LIST_PERMISSIONS)
 @utils.wrap_to_dict(RESP_FIELDS)
-def list_permissions(session, lister, **filters):
+def list_permissions(lister, session=None, **filters):
     """list permissions."""
     return utils.list_db_objects(
         session, models.Permission, **filters
@@ -282,8 +282,8 @@ def list_permissions(session, lister, **filters):
 @user_api.check_user_permission_in_session(PERMISSION_LIST_PERMISSIONS)
 @utils.wrap_to_dict(RESP_FIELDS)
 def get_permission(
-    session, getter, permission_id,
-    exception_when_missing=True, **kwargs
+    getter, permission_id,
+    exception_when_missing=True, session=None, **kwargs
 ):
     """get permissions."""
     return utils.get_db_object(
diff --git a/compass/db/api/switch.py b/compass/db/api/switch.py
index 93a0f8c0..eb1ecc04 100644
--- a/compass/db/api/switch.py
+++ b/compass/db/api/switch.py
@@ -140,8 +140,8 @@ def get_switch_internal(
 )
 @utils.wrap_to_dict(RESP_FIELDS)
 def get_switch(
-    session, getter, switch_id,
-    exception_when_missing=True, **kwargs
+    getter, switch_id,
+    exception_when_missing=True, session=None, **kwargs
 ):
     """get field dict of a switch."""
     return utils.get_db_object(
@@ -156,7 +156,7 @@ def get_switch(
     permission.PERMISSION_LIST_SWITCHES
 )
 @utils.wrap_to_dict(RESP_FIELDS)
-def list_switches(session, lister, **filters):
+def list_switches(lister, session=None, **filters):
     """List switches."""
     switches = utils.list_db_objects(
         session, models.Switch, **filters
@@ -176,7 +176,7 @@ def list_switches(session, lister, **filters):
     permission.PERMISSION_DEL_SWITCH
 )
 @utils.wrap_to_dict(RESP_FIELDS)
-def del_switch(session, deleter, switch_id, **kwargs):
+def del_switch(deleter, switch_id, session=None, **kwargs):
     """Delete a switch."""
     switch = utils.get_db_object(session, models.Switch, id=switch_id)
     default_switch_ip_int = long(netaddr.IPAddress(setting.DEFAULT_SWITCH_IP))
@@ -212,8 +212,8 @@ def del_switch(session, deleter, switch_id, **kwargs):
 )
 @utils.wrap_to_dict(RESP_FIELDS)
 def add_switch(
-    session, creator, exception_when_existing=True,
-    ip=None, **kwargs
+    creator, exception_when_existing=True,
+    ip=None, session=None, **kwargs
 ):
     """Create a switch."""
     ip_int = long(netaddr.IPAddress(ip))
@@ -230,9 +230,6 @@ def update_switch_internal(session, switch, **kwargs):
     )
 
 
-@user_api.check_user_permission_in_session(
-    permission.PERMISSION_ADD_SWITCH
-)
 @utils.wrap_to_dict(RESP_FIELDS)
 def _update_switch(session, updater, switch_id, **kwargs):
     """Update a switch."""
@@ -254,7 +251,10 @@ def _update_switch(session, updater, switch_id, **kwargs):
     put_filters=_check_filters
 )
 @database.run_in_session()
-def update_switch(session, updater, switch_id, **kwargs):
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_ADD_SWITCH
+)
+def update_switch(updater, switch_id, session=None, **kwargs):
     """Update fields of a switch."""
     return _update_switch(session, updater, switch_id, **kwargs)
 
@@ -274,7 +274,7 @@ def update_switch(session, updater, switch_id, **kwargs):
 @utils.output_validates(
     credentials=utils.check_switch_credentials
 )
-def patch_switch(session, updater, switch_id, **kwargs):
+def patch_switch(updater, switch_id, session=None, **kwargs):
     """Patch fields of a switch."""
     return _update_switch(session, updater, switch_id, **kwargs)
 
@@ -285,7 +285,7 @@ def patch_switch(session, updater, switch_id, **kwargs):
     permission.PERMISSION_LIST_SWITCH_FILTERS
 )
 @utils.wrap_to_dict(RESP_FILTERS_FIELDS)
-def list_switch_filters(session, lister, **filters):
+def list_switch_filters(lister, session=None, **filters):
     """List switch filters."""
     return utils.list_db_objects(
         session, models.Switch, **filters
@@ -299,7 +299,7 @@ def list_switch_filters(session, lister, **filters):
 )
 @utils.wrap_to_dict(RESP_FILTERS_FIELDS)
 def get_switch_filters(
-    session, getter, switch_id, **kwargs
+    getter, switch_id, session=None, **kwargs
 ):
     """get switch filter."""
     return utils.get_db_object(
@@ -320,7 +320,7 @@ def get_switch_filters(
     permission.PERMISSION_UPDATE_SWITCH_FILTERS
 )
 @utils.wrap_to_dict(RESP_FILTERS_FIELDS)
-def update_switch_filters(session, updater, switch_id, **kwargs):
+def update_switch_filters(updater, switch_id, session=None, **kwargs):
     """Update a switch filter."""
     switch = utils.get_db_object(session, models.Switch, id=switch_id)
     return utils.update_db_object(session, switch, **kwargs)
@@ -339,7 +339,7 @@ def update_switch_filters(session, updater, switch_id, **kwargs):
     permission.PERMISSION_UPDATE_SWITCH_FILTERS
 )
 @utils.wrap_to_dict(RESP_FILTERS_FIELDS)
-def patch_switch_filter(session, updater, switch_id, **kwargs):
+def patch_switch_filter(updater, switch_id, session=None, **kwargs):
     """Patch a switch filter."""
     switch = utils.get_db_object(session, models.Switch, id=switch_id)
     return utils.update_db_object(session, switch, **kwargs)
@@ -399,9 +399,6 @@ def _filter_vlans(vlan_filter, obj):
     return True
 
 
-@user_api.check_user_permission_in_session(
-    permission.PERMISSION_LIST_SWITCH_MACHINES
-)
 @utils.output_filters(
     port=_filter_port, vlans=_filter_vlans,
     tag=utils.general_filter_callback,
@@ -415,9 +412,6 @@ def _filter_switch_machines(session, user, switch_machines):
     ]
 
 
-@user_api.check_user_permission_in_session(
-    permission.PERMISSION_LIST_SWITCH_MACHINES
-)
 @utils.output_filters(
     missing_ok=True,
     port=_filter_port, vlans=_filter_vlans,
@@ -454,7 +448,10 @@ def _filter_switch_machines_hosts(session, user, switch_machines):
     optional_support_keys=SUPPORTED_MACHINES_FIELDS
 )
 @database.run_in_session()
-def list_switch_machines(session, getter, switch_id, **filters):
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_LIST_SWITCH_MACHINES
+)
+def list_switch_machines(getter, switch_id, session=None, **filters):
     """Get switch machines."""
     switch_machines = get_switch_machines_internal(
         session, switch_id=switch_id, **filters
@@ -469,7 +466,10 @@ def list_switch_machines(session, getter, switch_id, **filters):
     optional_support_keys=SUPPORTED_SWITCH_MACHINES_FIELDS
 )
 @database.run_in_session()
-def list_switchmachines(session, lister, **filters):
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_LIST_SWITCH_MACHINES
+)
+def list_switchmachines(lister, session=None, **filters):
     """List switch machines."""
     switch_machines = get_switch_machines_internal(
         session, **filters
@@ -483,7 +483,10 @@ def list_switchmachines(session, lister, **filters):
     optional_support_keys=SUPPORTED_MACHINES_HOSTS_FIELDS
 )
 @database.run_in_session()
-def list_switch_machines_hosts(session, getter, switch_id, **filters):
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_LIST_SWITCH_MACHINES
+)
+def list_switch_machines_hosts(getter, switch_id, session=None, **filters):
     """Get switch machines hosts."""
     switch_machines = get_switch_machines_internal(
         session, switch_id=switch_id, **filters
@@ -500,7 +503,10 @@ def list_switch_machines_hosts(session, getter, switch_id, **filters):
     optional_support_keys=SUPPORTED_SWITCH_MACHINES_HOSTS_FIELDS
 )
 @database.run_in_session()
-def list_switchmachines_hosts(session, lister, **filters):
+@user_api.check_user_permission_in_session(
+    permission.PERMISSION_LIST_SWITCH_MACHINES
+)
+def list_switchmachines_hosts(lister, session=None, **filters):
     """List switch machines hosts."""
     switch_machines = get_switch_machines_internal(
         session, **filters
@@ -528,9 +534,9 @@ def list_switchmachines_hosts(session, lister, **filters):
 )
 @utils.wrap_to_dict(RESP_MACHINES_FIELDS)
 def add_switch_machine(
-    session, creator, switch_id,
+    creator, switch_id,
     exception_when_existing=True,
-    mac=None, **kwargs
+    mac=None, session=None, **kwargs
 ):
     """Add switch machine."""
     switch = utils.get_db_object(
@@ -560,7 +566,7 @@ def add_switch_machine(
     permission.PERMISSION_UPDATE_SWITCH_MACHINES
 )
 @utils.wrap_to_dict(RESP_ACTION_FIELDS)
-def poll_switch_machines(session, poller, switch_id, **kwargs):
+def poll_switch_machines(poller, switch_id, session=None, **kwargs):
     """poll switch machines."""
     from compass.tasks import client as celery_client
     switch = utils.get_db_object(session, models.Switch, id=switch_id)
@@ -582,8 +588,8 @@ def poll_switch_machines(session, poller, switch_id, **kwargs):
 )
 @utils.wrap_to_dict(RESP_MACHINES_FIELDS)
 def get_switch_machine(
-    session, getter, switch_id, machine_id,
-    exception_when_missing=True, **kwargs
+    getter, switch_id, machine_id,
+    exception_when_missing=True, session=None, **kwargs
 ):
     """get field dict of a switch machine."""
     return utils.get_db_object(
@@ -600,8 +606,8 @@ def get_switch_machine(
 )
 @utils.wrap_to_dict(RESP_MACHINES_FIELDS)
 def get_switchmachine(
-    session, getter, switch_machine_id,
-    exception_when_missing=True,
+    getter, switch_machine_id,
+    exception_when_missing=True, session=None,
     **kwargs
 ):
     """get field dict of a switch machine."""
@@ -641,7 +647,10 @@ def update_switch_machine_internal(
     permission.PERMISSION_ADD_SWITCH_MACHINE
 )
 @utils.wrap_to_dict(RESP_MACHINES_FIELDS)
-def update_switch_machine(session, updater, switch_id, machine_id, **kwargs):
+def update_switch_machine(
+    updater, switch_id, machine_id,
+    session=None, **kwargs
+):
     """Update switch machine."""
     switch_machine = utils.get_db_object(
         session, models.SwitchMachine,
@@ -663,7 +672,7 @@ def update_switch_machine(session, updater, switch_id, machine_id, **kwargs):
     permission.PERMISSION_ADD_SWITCH_MACHINE
 )
 @utils.wrap_to_dict(RESP_MACHINES_FIELDS)
-def update_switchmachine(session, updater, switch_machine_id, **kwargs):
+def update_switchmachine(updater, switch_machine_id, session=None, **kwargs):
     """Update switch machine."""
     switch_machine = utils.get_db_object(
         session, models.SwitchMachine,
@@ -691,7 +700,10 @@ def update_switchmachine(session, updater, switch_machine_id, **kwargs):
     permission.PERMISSION_ADD_SWITCH_MACHINE
 )
 @utils.wrap_to_dict(RESP_MACHINES_FIELDS)
-def patch_switch_machine(session, updater, switch_id, machine_id, **kwargs):
+def patch_switch_machine(
+    updater, switch_id, machine_id,
+    session=None, **kwargs
+):
     """Patch switch machine."""
     switch_machine = utils.get_db_object(
         session, models.SwitchMachine,
@@ -719,7 +731,7 @@ def patch_switch_machine(session, updater, switch_id, machine_id, **kwargs):
     permission.PERMISSION_ADD_SWITCH_MACHINE
 )
 @utils.wrap_to_dict(RESP_MACHINES_FIELDS)
-def patch_switchmachine(session, updater, switch_machine_id, **kwargs):
+def patch_switchmachine(updater, switch_machine_id, session=None, **kwargs):
     """Patch switch machine."""
     switch_machine = utils.get_db_object(
         session, models.SwitchMachine,
@@ -737,7 +749,7 @@ def patch_switchmachine(session, updater, switch_machine_id, **kwargs):
     permission.PERMISSION_DEL_SWITCH_MACHINE
 )
 @utils.wrap_to_dict(RESP_MACHINES_FIELDS)
-def del_switch_machine(session, deleter, switch_id, machine_id, **kwargs):
+def del_switch_machine(deleter, switch_id, machine_id, session=None, **kwargs):
     """Delete switch machine by switch id and machine id."""
     switch_machine = utils.get_db_object(
         session, models.SwitchMachine,
@@ -765,7 +777,7 @@ def del_switch_machine(session, deleter, switch_id, machine_id, **kwargs):
     permission.PERMISSION_DEL_SWITCH_MACHINE
 )
 @utils.wrap_to_dict(RESP_MACHINES_FIELDS)
-def del_switchmachine(session, deleter, switch_machine_id, **kwargs):
+def del_switchmachine(deleter, switch_machine_id, session=None, **kwargs):
     """Delete switch machine by switch_machine_id."""
     switch_machine = utils.get_db_object(
         session, models.SwitchMachine,
@@ -835,9 +847,9 @@ def _set_machines(session, switch, machines):
 )
 @utils.wrap_to_dict(RESP_MACHINES_FIELDS)
 def update_switch_machines(
-    session, updater, switch_id,
+    updater, switch_id,
     add_machines=[], remove_machines=[],
-    set_machines=None, **kwargs
+    set_machines=None, session=None, **kwargs
 ):
     """update switch machines."""
     switch = utils.get_db_object(
diff --git a/compass/db/api/user.py b/compass/db/api/user.py
index 148d277b..4600f9c0 100644
--- a/compass/db/api/user.py
+++ b/compass/db/api/user.py
@@ -101,9 +101,13 @@ def _check_user_permission(session, user, permission):
 def check_user_permission_in_session(permission):
     def decorator(func):
         @functools.wraps(func)
-        def wrapper(session, user, *args, **kwargs):
+        def wrapper(user, *args, **kwargs):
+            if 'session' in kwargs.keys():
+                session = kwargs['session']
+            else:
+                session = args[-1]
             _check_user_permission(session, user, permission)
-            return func(session, user, *args, **kwargs)
+            return func(user, *args, **kwargs)
         return wrapper
     return decorator
 
@@ -223,7 +227,7 @@ class UserWrapper(UserMixin):
 
 
 @database.run_in_session()
-def get_user_object(session, email, **kwargs):
+def get_user_object(email, session=None, **kwargs):
     user = utils.get_db_object(
         session, models.User, False, email=email
     )
@@ -237,7 +241,7 @@ def get_user_object(session, email, **kwargs):
 
 
 @database.run_in_session()
-def get_user_object_from_token(session, token):
+def get_user_object_from_token(token, session=None):
     expire_timestamp = {
         'ge': datetime.datetime.now()
     }
@@ -262,7 +266,7 @@ def get_user_object_from_token(session, token):
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_TOKEN_FIELDS)
 def record_user_token(
-    session, user, token, expire_timestamp
+    user, token, expire_timestamp, session=None
 ):
     """record user token in database."""
     user_token = utils.get_db_object(
@@ -285,7 +289,7 @@ def record_user_token(
 @utils.supported_filters()
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_TOKEN_FIELDS)
-def clean_user_token(session, user, token):
+def clean_user_token(user, token, session=None):
     """clean user token in database."""
     return utils.del_db_objects(
         session, models.UserToken,
@@ -298,8 +302,8 @@ def clean_user_token(session, user, token):
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_FIELDS)
 def get_user(
-    session, getter, user_id,
-    exception_when_missing=True, **kwargs
+    getter, user_id,
+    exception_when_missing=True, session=None, **kwargs
 ):
     """get field dict of a user."""
     return utils.get_db_object(
@@ -311,8 +315,8 @@ def get_user(
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_FIELDS)
 def get_current_user(
-    session, getter,
-    exception_when_missing=True, **kwargs
+    getter,
+    exception_when_missing=True, session=None, **kwargs
 ):
     """get field dict of a user."""
     return utils.get_db_object(
@@ -326,7 +330,7 @@ def get_current_user(
 @check_user_admin()
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_FIELDS)
-def list_users(session, lister, **filters):
+def list_users(lister, session=None, **filters):
     """List fields of all users by some fields."""
     return utils.list_db_objects(
         session, models.User, **filters
@@ -343,9 +347,9 @@ def list_users(session, lister, **filters):
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_FIELDS)
 def add_user(
-    session, creator,
+    creator,
     exception_when_existing=True,
-    **kwargs
+    session=None, **kwargs
 ):
     """Create a user and return created user object."""
     return add_user_internal(
@@ -357,7 +361,7 @@ def add_user(
 @check_user_admin()
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_FIELDS)
-def del_user(session, deleter, user_id, **kwargs):
+def del_user(deleter, user_id, session=None, **kwargs):
     """delete a user and return the deleted user object."""
     user = utils.get_db_object(session, models.User, id=user_id)
     return utils.del_db_object(session, user)
@@ -370,7 +374,7 @@ def del_user(session, deleter, user_id, **kwargs):
 @utils.input_validates(email=_check_email)
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_FIELDS)
-def update_user(session, updater, user_id, **kwargs):
+def update_user(updater, user_id, session=None, **kwargs):
     """Update a user and return the updated user object."""
     user = utils.get_db_object(
         session, models.User, id=user_id
@@ -395,7 +399,7 @@ def update_user(session, updater, user_id, **kwargs):
 @check_user_admin_or_owner()
 @database.run_in_session()
 @utils.wrap_to_dict(PERMISSION_RESP_FIELDS)
-def get_permissions(session, lister, user_id, **kwargs):
+def get_permissions(lister, user_id, session=None, **kwargs):
     """List permissions of a user."""
     return utils.list_db_objects(
         session, models.UserPermission, user_id=user_id, **kwargs
@@ -407,8 +411,8 @@ def get_permissions(session, lister, user_id, **kwargs):
 @database.run_in_session()
 @utils.wrap_to_dict(PERMISSION_RESP_FIELDS)
 def get_permission(
-    session, getter, user_id, permission_id,
-    exception_when_missing=True, **kwargs
+    getter, user_id, permission_id,
+    exception_when_missing=True, session=None, **kwargs
 ):
     """Get a specific user permission."""
     return utils.get_db_object(
@@ -423,7 +427,7 @@ def get_permission(
 @check_user_admin_or_owner()
 @database.run_in_session()
 @utils.wrap_to_dict(PERMISSION_RESP_FIELDS)
-def del_permission(session, deleter, user_id, permission_id, **kwargs):
+def del_permission(deleter, user_id, permission_id, session=None, **kwargs):
     """Delete a specific user permission."""
     user_permission = utils.get_db_object(
         session, models.UserPermission,
@@ -441,8 +445,8 @@ def del_permission(session, deleter, user_id, permission_id, **kwargs):
 @database.run_in_session()
 @utils.wrap_to_dict(PERMISSION_RESP_FIELDS)
 def add_permission(
-    session, creator, user_id,
-    exception_when_missing=True, permission_id=None
+    creator, user_id,
+    exception_when_missing=True, permission_id=None, session=None
 ):
     """Add an user permission."""
     return utils.add_db_object(
@@ -467,9 +471,9 @@ def _get_permission_filters(permission_ids):
 @database.run_in_session()
 @utils.wrap_to_dict(PERMISSION_RESP_FIELDS)
 def update_permissions(
-    session, updater, user_id,
+    updater, user_id,
     add_permissions=[], remove_permissions=[],
-    set_permissions=None, **kwargs
+    set_permissions=None, session=None, **kwargs
 ):
     """update user permissions."""
     user = utils.get_db_object(session, models.User, id=user_id)
diff --git a/compass/db/api/user_log.py b/compass/db/api/user_log.py
index c5fcae23..4f57e798 100644
--- a/compass/db/api/user_log.py
+++ b/compass/db/api/user_log.py
@@ -28,7 +28,7 @@ RESP_FIELDS = ['user_id', 'logs', 'timestamp']
 
 
 @database.run_in_session()
-def log_user_action(session, user_id, action):
+def log_user_action(user_id, action, session=None):
     """Log user action."""
     utils.add_db_object(
         session, models.UserLog, True, user_id=user_id, action=action
@@ -39,7 +39,7 @@ def log_user_action(session, user_id, action):
 @user_api.check_user_admin_or_owner()
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_FIELDS)
-def list_user_actions(session, lister, user_id, **filters):
+def list_user_actions(lister, user_id, session=None, **filters):
     """list user actions."""
     return utils.list_db_objects(
         session, models.UserLog, order_by=['timestamp'],
@@ -51,7 +51,7 @@ def list_user_actions(session, lister, user_id, **filters):
 @user_api.check_user_admin()
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_FIELDS)
-def list_actions(session, lister, **filters):
+def list_actions(lister, session=None, **filters):
     """list actions."""
     return utils.list_db_objects(
         session, models.UserLog, order_by=['timestamp'], **filters
@@ -62,7 +62,7 @@ def list_actions(session, lister, **filters):
 @user_api.check_user_admin_or_owner()
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_FIELDS)
-def del_user_actions(session, deleter, user_id, **filters):
+def del_user_actions(deleter, user_id, session=None, **filters):
     """delete user actions."""
     return utils.del_db_objects(
         session, models.UserLog, user_id=user_id, **filters
@@ -73,7 +73,7 @@ def del_user_actions(session, deleter, user_id, **filters):
 @user_api.check_user_admin()
 @database.run_in_session()
 @utils.wrap_to_dict(RESP_FIELDS)
-def del_actions(session, deleter, **filters):
+def del_actions(deleter, session=None, **filters):
     """delete actions."""
     return utils.del_db_objects(
         session, models.UserLog, **filters
diff --git a/compass/db/api/utils.py b/compass/db/api/utils.py
index 988b64ad..53c7240e 100644
--- a/compass/db/api/utils.py
+++ b/compass/db/api/utils.py
@@ -20,6 +20,7 @@ import logging
 import netaddr
 import re
 
+from inspect import isfunction
 from sqlalchemy import and_
 from sqlalchemy import or_
 
@@ -255,6 +256,17 @@ def _replace_output(data, **output_mapping):
     return info
 
 
+def get_wrapped_func(func):
+    """Get wrapped function instance."""
+    if func.func_closure:
+        for closure in func.func_closure:
+            if isfunction(closure.cell_contents):
+                return get_wrapped_func(closure.cell_contents)
+        return func
+    else:
+        return func
+
+
 def wrap_to_dict(support_keys=[], **filters):
     def decorator(func):
         @functools.wraps(func)
@@ -335,14 +347,18 @@ def replace_filters(**filter_mapping):
 def supported_filters(
     support_keys=[],
     optional_support_keys=[],
-    ignore_support_keys=[]
+    ignore_support_keys=[],
 ):
     def decorator(func):
         @functools.wraps(func)
         def wrapper(*args, **filters):
+            wrapped_func = get_wrapped_func(func)
+            argspec = inspect.getargspec(wrapped_func)
+            wrapped_args = argspec.args
             must_support_keys = set(support_keys)
             all_support_keys = must_support_keys | set(optional_support_keys)
-            filter_keys = set(filters)
+            filter_keys = set(filters) - set(wrapped_args)
+            wrapped_support_keys = set(filters) | set(wrapped_args)
             unsupported_keys = (
                 filter_keys - all_support_keys - set(ignore_support_keys)
             )
@@ -352,7 +368,7 @@ def supported_filters(
                         list(unsupported_keys)
                     )
                 )
-            missing_keys = must_support_keys - filter_keys
+            missing_keys = must_support_keys - wrapped_support_keys
             if missing_keys:
                 raise exception.InvalidParameter(
                     'filter keys %s not found' % str(
diff --git a/compass/tests/db/api/test_cluster.py b/compass/tests/db/api/test_cluster.py
index 85fd4d8c..061b9152 100644
--- a/compass/tests/db/api/test_cluster.py
+++ b/compass/tests/db/api/test_cluster.py
@@ -326,6 +326,54 @@ class TestAddCluster(ClusterTestCase):
             result.append(add_cluster['name'])
         self.assertIn('test_add_cluster', result)
 
+    def test_add_cluster_position_args(self):
+        cluster.add_cluster(
+            self.user_object,
+            True,
+            'test_add_cluster_position',
+            adapter_id=self.adapter_id,
+            os_id=self.os_id,
+            flavor_id=self.flavor_id,
+        )
+        add_clusters = cluster.list_clusters(self.user_object)
+        result = []
+        for add_cluster in add_clusters:
+            result.append(add_cluster['name'])
+        self.assertIn('test_add_cluster_position', result)
+
+    def test_add_cluster_session(self):
+        with database.session() as session:
+            cluster.add_cluster(
+                self.user_object,
+                adapter_id=self.adapter_id,
+                os_id=self.os_id,
+                flavor_id=self.flavor_id,
+                name='test_add_cluster_session',
+                session=session
+            )
+        add_clusters = cluster.list_clusters(self.user_object)
+        result = []
+        for add_cluster in add_clusters:
+            result.append(add_cluster['name'])
+        self.assertIn('test_add_cluster_session', result)
+
+    def test_add_cluster_position_args_session(self):
+        with database.session() as session:
+            cluster.add_cluster(
+                self.user_object,
+                True,
+                'test_add_cluster_position_session',
+                session,
+                adapter_id=self.adapter_id,
+                os_id=self.os_id,
+                flavor_id=self.flavor_id,
+            )
+        add_clusters = cluster.list_clusters(self.user_object)
+        result = []
+        for add_cluster in add_clusters:
+            result.append(add_cluster['name'])
+        self.assertIn('test_add_cluster_position_session', result)
+
 
 class TestUpdateCluster(ClusterTestCase):
     """Test update cluster."""
@@ -1927,7 +1975,6 @@ class TestAddClusterhostLogHistory(ClusterTestCase):
             self.user_object,
             self.clusterhost_id[0],
             filename='add_log_file'
-
         )
         logs = cluster.get_clusterhost_log_histories(
             self.user_object,
@@ -1938,6 +1985,57 @@ class TestAddClusterhostLogHistory(ClusterTestCase):
             result.append(log['filename'])
         self.assertIn('add_log_file', result)
 
+    def test_add_clusterhost_log_history_position_args(self):
+        cluster.add_clusterhost_log_history(
+            self.user_object,
+            self.clusterhost_id[0],
+            False,
+            'add_log_file_position'
+        )
+        logs = cluster.get_clusterhost_log_histories(
+            self.user_object,
+            self.clusterhost_id[0]
+        )
+        result = []
+        for log in logs:
+            result.append(log['filename'])
+        self.assertIn('add_log_file_position', result)
+
+    def test_add_clusterhost_log_history_session(self):
+        with database.session() as session:
+            cluster.add_clusterhost_log_history(
+                self.user_object,
+                self.clusterhost_id[0],
+                filename='add_log_file_session',
+                session=session
+            )
+        logs = cluster.get_clusterhost_log_histories(
+            self.user_object,
+            self.clusterhost_id[0]
+        )
+        result = []
+        for log in logs:
+            result.append(log['filename'])
+        self.assertIn('add_log_file_session', result)
+
+    def test_add_clusterhost_log_history_position_args_session(self):
+        with database.session() as session:
+            cluster.add_clusterhost_log_history(
+                self.user_object,
+                self.clusterhost_id[0],
+                False,
+                'add_log_file_position_session',
+                session
+            )
+        logs = cluster.get_clusterhost_log_histories(
+            self.user_object,
+            self.clusterhost_id[0]
+        )
+        result = []
+        for log in logs:
+            result.append(log['filename'])
+        self.assertIn('add_log_file_position_session', result)
+
 
 class TestAddClusterHostLogHistory(ClusterTestCase):
     """Test add cluster host log history."""
@@ -1965,6 +2063,63 @@ class TestAddClusterHostLogHistory(ClusterTestCase):
             result.append(log['filename'])
         self.assertIn('add_log_file', result)
 
+    def test_add_cluster_host_log_history_position(self):
+        cluster.add_cluster_host_log_history(
+            self.user_object,
+            self.cluster_id,
+            self.host_id[0],
+            False,
+            'add_log_file_position'
+        )
+        logs = cluster.get_cluster_host_log_histories(
+            self.user_object,
+            self.cluster_id,
+            self.host_id[0]
+        )
+        result = []
+        for log in logs:
+            result.append(log['filename'])
+        self.assertIn('add_log_file_position', result)
+
+    def test_add_cluster_host_log_history_session(self):
+        with database.session() as session:
+            cluster.add_cluster_host_log_history(
+                self.user_object,
+                self.cluster_id,
+                self.host_id[0],
+                filename='add_log_file_session',
+                session=session
+            )
+        logs = cluster.get_cluster_host_log_histories(
+            self.user_object,
+            self.cluster_id,
+            self.host_id[0]
+        )
+        result = []
+        for log in logs:
+            result.append(log['filename'])
+        self.assertIn('add_log_file_session', result)
+
+    def test_add_cluster_host_log_history_position_session(self):
+        with database.session() as session:
+            cluster.add_cluster_host_log_history(
+                self.user_object,
+                self.cluster_id,
+                self.host_id[0],
+                False,
+                'add_log_file_position_session',
+                session
+            )
+        logs = cluster.get_cluster_host_log_histories(
+            self.user_object,
+            self.cluster_id,
+            self.host_id[0]
+        )
+        result = []
+        for log in logs:
+            result.append(log['filename'])
+        self.assertIn('add_log_file_position_session', result)
+
 
 if __name__ == '__main__':
     flags.init()
diff --git a/compass/tests/db/api/test_host.py b/compass/tests/db/api/test_host.py
index 80e48ee5..c45c06bd 100644
--- a/compass/tests/db/api/test_host.py
+++ b/compass/tests/db/api/test_host.py
@@ -835,6 +835,66 @@ class TestAddHostNetwork(HostTestCase):
             result.append(item['ip'])
         self.assertIn('10.145.88.20', result)
 
+    def test_add_host_network_position(self):
+        host.add_host_network(
+            self.user_object,
+            self.host_ids[0],
+            True,
+            'eth1',
+            ip='10.145.88.30',
+            subnet_id=self.subnet_ids[0],
+            is_mgmt=True
+        )
+        host_network = host.list_host_networks(
+            self.user_object,
+            self.host_ids[0]
+        )
+        result = []
+        for item in host_network:
+            result.append(item['ip'])
+        self.assertIn('10.145.88.30', result)
+
+    def test_add_host_network_session(self):
+        with database.session() as session:
+            host.add_host_network(
+                self.user_object,
+                self.host_ids[0],
+                interface='eth1',
+                ip='10.145.88.40',
+                subnet_id=self.subnet_ids[0],
+                is_mgmt=True,
+                session=session
+            )
+        host_network = host.list_host_networks(
+            self.user_object,
+            self.host_ids[0]
+        )
+        result = []
+        for item in host_network:
+            result.append(item['ip'])
+        self.assertIn('10.145.88.40', result)
+
+    def test_add_host_network_position_session(self):
+        with database.session() as session:
+            host.add_host_network(
+                self.user_object,
+                self.host_ids[0],
+                True,
+                'eth1',
+                session,
+                ip='10.145.88.50',
+                subnet_id=self.subnet_ids[0],
+                is_mgmt=True
+            )
+        host_network = host.list_host_networks(
+            self.user_object,
+            self.host_ids[0]
+        )
+        result = []
+        for item in host_network:
+            result.append(item['ip'])
+        self.assertIn('10.145.88.50', result)
+
     def test_invalid_parameter(self):
         self.assertRaises(
             exception.InvalidParameter,
@@ -1167,6 +1227,57 @@ class TestAddHostLogHistory(HostTestCase):
             result.append(log['filename'])
         self.assertIn('add_log', result)
 
+    def test_add_host_log_history_position(self):
+        host.add_host_log_history(
+            self.user_object,
+            self.host_ids[0],
+            False,
+            'add_log_position'
+        )
+        logs = host.get_host_log_histories(
+            self.user_object,
+            self.host_ids[0]
+        )
+        result = []
+        for log in logs:
+            result.append(log['filename'])
+        self.assertIn('add_log_position', result)
+
+    def test_add_host_log_history_session(self):
+        with database.session() as session:
+            host.add_host_log_history(
+                self.user_object,
+                self.host_ids[0],
+                filename='add_log_session',
+                session=session
+            )
+        logs = host.get_host_log_histories(
+            self.user_object,
+            self.host_ids[0]
+        )
+        result = []
+        for log in logs:
+            result.append(log['filename'])
+        self.assertIn('add_log_session', result)
+
+    def test_add_host_log_history_position_session(self):
+        with database.session() as session:
+            host.add_host_log_history(
+                self.user_object,
+                self.host_ids[0],
+                False,
+                'add_log_position_session',
+                session
+            )
+        logs = host.get_host_log_histories(
+            self.user_object,
+            self.host_ids[0]
+        )
+        result = []
+        for log in logs:
+            result.append(log['filename'])
+        self.assertIn('add_log_position_session', result)
+
 
 class TestPoweronHost(HostTestCase):
     """Test poweron host."""
diff --git a/compass/tests/db/api/test_network.py b/compass/tests/db/api/test_network.py
index b3e18df7..9909a9a6 100644
--- a/compass/tests/db/api/test_network.py
+++ b/compass/tests/db/api/test_network.py
@@ -103,13 +103,54 @@ class TestAddSubnet(BaseTest):
             self.user_object,
             subnet='10.145.89.0/24'
         )
-        add_subnet = network.list_subnets(
+        add_subnets = network.list_subnets(
             self.user_object
         )
         expected = '10.145.89.0/24'
-        self.assertTrue(
-            item in add_subnet[0].items() for item in expected
+        for add_subnet in add_subnets:
+            self.assertEqual(expected, add_subnet['subnet'])
+
+    def test_add_subnet_position(self):
+        network.add_subnet(
+            self.user_object,
+            True,
+            '10.145.89.0/23'
         )
+        add_subnets = network.list_subnets(
+            self.user_object
+        )
+        expected = '10.145.89.0/23'
+        for add_subnet in add_subnets:
+            self.assertEqual(expected, add_subnet['subnet'])
+
+    def test_add_subnet_session(self):
+        with database.session() as session:
+            network.add_subnet(
+                self.user_object,
+                subnet='10.145.89.0/22',
+                session=session
+            )
+        add_subnets = network.list_subnets(
+            self.user_object
+        )
+        expected = '10.145.89.0/22'
+        for add_subnet in add_subnets:
+            self.assertEqual(expected, add_subnet['subnet'])
+
+    def test_add_subnet_position_session(self):
+        with database.session() as session:
+            network.add_subnet(
+                self.user_object,
+                True,
+                '10.145.89.0/21',
+                session
+            )
+        add_subnets = network.list_subnets(
+            self.user_object
+        )
+        expected = '10.145.89.0/21'
+        for add_subnet in add_subnets:
+            self.assertEqual(expected, add_subnet['subnet'])
 
 
 class TestUpdateSubnet(BaseTest):
diff --git a/compass/tests/db/api/test_permission.py b/compass/tests/db/api/test_permission.py
index 806c696e..5b565da0 100644
--- a/compass/tests/db/api/test_permission.py
+++ b/compass/tests/db/api/test_permission.py
@@ -46,6 +46,7 @@ class TestListPermissions(BaseTest):
     def test_list_permissions(self):
         permissions = permission.list_permissions(self.user_object)
         self.assertIsNotNone(permissions)
+        self.assertEqual(49, len(permissions))
 
 
 class TestGetPermission(BaseTest):
@@ -60,6 +61,13 @@ class TestGetPermission(BaseTest):
     def test_get_permission(self):
         get_permission = permission.get_permission(self.user_object, 1)
         self.assertIsNotNone(get_permission)
+        expected = {
+            'alias': 'list permissions',
+            'description': 'list all permissions',
+            'id': 1,
+            'name': 'list_permissions'
+        }
+        self.assertDictEqual(get_permission, expected)
 
 
 if __name__ == '__main__':
diff --git a/compass/tests/db/api/test_switch.py b/compass/tests/db/api/test_switch.py
index db7a6b71..72906475 100644
--- a/compass/tests/db/api/test_switch.py
+++ b/compass/tests/db/api/test_switch.py
@@ -64,11 +64,42 @@ class TestAddSwitch(BaseTest):
     def test_add_switch(self):
         add_switch = switch.add_switch(
             self.user_object,
-            ip='2887583784'
+            ip='2887583784',
         )
         expected = '172.29.8.40'
         self.assertEqual(expected, add_switch['ip'])
 
+    def test_add_switch_position_args(self):
+        add_switch = switch.add_switch(
+            self.user_object,
+            True,
+            '2887583784',
+        )
+        print add_switch
+        expected = '172.29.8.40'
+        self.assertEqual(expected, add_switch['ip'])
+
+    def test_add_switch_session(self):
+        with database.session() as session:
+            add_switch = switch.add_switch(
+                self.user_object,
+                ip='2887583784',
+                session=session
+            )
+        expected = '172.29.8.40'
+        self.assertEqual(expected, add_switch['ip'])
+
+    def test_add_switch_position_args_session(self):
+        with database.session() as session:
+            add_switch = switch.add_switch(
+                self.user_object,
+                True,
+                '2887583784',
+                session
+            )
+        expected = '172.29.8.40'
+        self.assertEqual(expected, add_switch['ip'])
+
 
 class TestListSwitches(BaseTest):
     """Test list switch."""
@@ -304,6 +335,42 @@ class TestAddSwitchMachine(BaseTest):
         expected = '28:6e:d4:46:c4:25'
         self.assertEqual(expected, add_switch_machine['mac'])
 
+    def test_add_switch_machine_position_args(self):
+        add_switch_machine = switch.add_switch_machine(
+            self.user_object,
+            1,
+            True,
+            '28:6e:d4:46:c4:25',
+            port='1'
+        )
+        expected = '28:6e:d4:46:c4:25'
+        self.assertEqual(expected, add_switch_machine['mac'])
+
+    def test_add_switch_machine_session(self):
+        with database.session() as session:
+            add_switch_machine = switch.add_switch_machine(
+                self.user_object,
+                1,
+                mac='28:6e:d4:46:c4:25',
+                session=session,
+                port='1'
+            )
+        expected = '28:6e:d4:46:c4:25'
+        self.assertEqual(expected, add_switch_machine['mac'])
+
+    def test_add_switch_machine_position_args_session(self):
+        with database.session() as session:
+            add_switch_machine = switch.add_switch_machine(
+                self.user_object,
+                1,
+                True,
+                '28:6e:d4:46:c4:25',
+                session,
+                port='1'
+            )
+        expected = '28:6e:d4:46:c4:25'
+        self.assertEqual(expected, add_switch_machine['mac'])
+
 
 class TestListSwitchMachines(BaseTest):
     """Test get switch machines."""
diff --git a/compass/tests/db/api/test_user.py b/compass/tests/db/api/test_user.py
index 8bfc7f05..98ea29a5 100644
--- a/compass/tests/db/api/test_user.py
+++ b/compass/tests/db/api/test_user.py
@@ -176,6 +176,16 @@ class TestAddUser(BaseTest):
         )
         self.assertEqual('test@abc.com', user_objs['email'])
 
+    def test_add_user_session(self):
+        with database.session() as session:
+            user_objs = user_api.add_user(
+                self.user_object,
+                email='test@abc.com',
+                password='password',
+                session=session
+            )
+        self.assertEqual('test@abc.com', user_objs['email'])
+
 
 class TestDelUser(BaseTest):
     """Test delete user."""
@@ -298,6 +308,60 @@ class TestAddDelUserPermission(BaseTest):
                 result = permission['name']
         self.assertEqual(result, 'list_switches')
 
+    def test_add_permission_position(self):
+        user_api.add_permission(
+            self.user_object,
+            self.user_object.id,
+            True,
+            2
+        )
+        permissions = user_api.get_permissions(
+            self.user_object,
+            self.user_object.id
+        )
+        result = None
+        for permission in permissions:
+            if permission['id'] == 2:
+                result = permission['name']
+        self.assertEqual(result, 'list_switches')
+
+    def test_add_permission_session(self):
+        with database.session() as session:
+            user_api.add_permission(
+                self.user_object,
+                self.user_object.id,
+                permission_id=2,
+                session=session
+            )
+        permissions = user_api.get_permissions(
+            self.user_object,
+            self.user_object.id
+        )
+        result = None
+        for permission in permissions:
+            if permission['id'] == 2:
+                result = permission['name']
+        self.assertEqual(result, 'list_switches')
+
+    def test_add_permission_position_session(self):
+        with database.session() as session:
+            user_api.add_permission(
+                self.user_object,
+                self.user_object.id,
+                True,
+                2,
+                session
+            )
+        permissions = user_api.get_permissions(
+            self.user_object,
+            self.user_object.id
+        )
+        result = None
+        for permission in permissions:
+            if permission['id'] == 2:
+                result = permission['name']
+        self.assertEqual(result, 'list_switches')
+
     def test_del_permission(self):
         user_api.del_permission(
             self.user_object,