diff --git a/server/apierrors/__init__.py b/server/apierrors/__init__.py
index 8064181..46fad7b 100644
--- a/server/apierrors/__init__.py
+++ b/server/apierrors/__init__.py
@@ -105,7 +105,6 @@ _error_codes = {
 
     (403, 'forbidden'): {
         10: ('routing_error', 'forbidden (routing error)'),
-        11: ('missing_routing_header', 'forbidden (missing routing header)'),
         12: ('blocked_internal_endpoint', 'forbidden (blocked internal endpoint)'),
         20: ('role_not_allowed', 'forbidden (not allowed for role)'),
         21: ('no_write_permission', 'forbidden (modification not allowed)'),
diff --git a/server/apimodels/base.py b/server/apimodels/base.py
index 842d338..51ba290 100644
--- a/server/apimodels/base.py
+++ b/server/apimodels/base.py
@@ -58,3 +58,7 @@ class UpdateResponse(models.Base):
 class PagedRequest(models.Base):
     page = fields.IntField()
     page_size = fields.IntField()
+
+
+class IdResponse(models.Base):
+    id = fields.StringField(required=True)
diff --git a/server/apimodels/tasks.py b/server/apimodels/tasks.py
index 5145522..a025aeb 100644
--- a/server/apimodels/tasks.py
+++ b/server/apimodels/tasks.py
@@ -1,6 +1,6 @@
 import six
 from jsonmodels import models
-from jsonmodels.fields import StringField, BoolField, IntField
+from jsonmodels.fields import StringField, BoolField, IntField, EmbeddedField
 from jsonmodels.validators import Enum
 
 from apimodels import DictField, ListField
@@ -9,6 +9,24 @@ from database.model.task.task import TaskType
 from database.utils import get_options
 
 
+class ArtifactTypeData(models.Base):
+    preview = StringField()
+    content_type = StringField()
+    data_hash = StringField()
+
+
+class Artifact(models.Base):
+    key = StringField(required=True)
+    type = StringField(required=True)
+    mode = StringField(validators=Enum("input", "output"), default="output")
+    uri = StringField()
+    hash = StringField()
+    content_size = IntField()
+    timestamp = IntField()
+    type_data = EmbeddedField(ArtifactTypeData)
+    display_data = ListField([list])
+
+
 class StartedResponse(UpdateResponse):
     started = IntField()
 
@@ -72,3 +90,22 @@ class CreateRequest(TaskData):
 
 class PingRequest(TaskRequest):
     pass
+
+
+class CloneRequest(TaskRequest):
+    new_task_name = StringField()
+    new_task_comment = StringField()
+    new_task_tags = ListField([str])
+    new_task_system_tags = ListField([str])
+    new_task_parent = StringField()
+    new_task_project = StringField()
+    execution_overrides = DictField()
+
+
+class AddOrUpdateArtifactsRequest(TaskRequest):
+    artifacts = ListField([Artifact], required=True)
+
+
+class AddOrUpdateArtifactsResponse(models.Base):
+    added = ListField([str])
+    updated = ListField([str])