diff --git a/api/core/workflow/human_input_compat.py b/api/core/workflow/human_input_compat.py
index 498a537d03..41b24635d9 100644
--- a/api/core/workflow/human_input_compat.py
+++ b/api/core/workflow/human_input_compat.py
@@ -19,11 +19,15 @@ from pydantic import AliasChoices, BaseModel, ConfigDict, Field, TypeAdapter
 
 from dify_graph.enums import BuiltinNodeTypes
 from dify_graph.nodes.base.variable_template_parser import VariableTemplateParser
-from dify_graph.nodes.human_input.enums import DeliveryMethodType
 from dify_graph.runtime import VariablePool
 from dify_graph.variables.consts import SELECTORS_LENGTH
 
 
+class DeliveryMethodType(enum.StrEnum):
+    WEBAPP = enum.auto()
+    EMAIL = enum.auto()
+
+
 class EmailRecipientType(enum.StrEnum):
     BOUND = "member"
     MEMBER = BOUND
diff --git a/api/dify_graph/constants.py b/api/dify_graph/constants.py
deleted file mode 100644
index 5b2e895161..0000000000
--- a/api/dify_graph/constants.py
+++ /dev/null
@@ -1,2 +0,0 @@
-CONVERSATION_VARIABLE_NODE_ID = "conversation"
-ENVIRONMENT_VARIABLE_NODE_ID = "env"
diff --git a/api/dify_graph/nodes/human_input/enums.py b/api/dify_graph/nodes/human_input/enums.py
index 5964d64dd7..3fb0ab4499 100644
--- a/api/dify_graph/nodes/human_input/enums.py
+++ b/api/dify_graph/nodes/human_input/enums.py
@@ -25,11 +25,6 @@ class HumanInputFormKind(enum.StrEnum):
     DELIVERY_TEST = enum.auto()  # Form created for delivery tests.
 
 
-class DeliveryMethodType(enum.StrEnum):
-    WEBAPP = enum.auto()
-    EMAIL = enum.auto()
-
-
 class ButtonStyle(enum.StrEnum):
     """Button styles for user actions."""
 
diff --git a/api/tests/test_containers_integration_tests/controllers/console/app/test_workflow_draft_variable.py b/api/tests/test_containers_integration_tests/controllers/console/app/test_workflow_draft_variable.py
index f037ad77c0..32cad239e6 100644
--- a/api/tests/test_containers_integration_tests/controllers/console/app/test_workflow_draft_variable.py
+++ b/api/tests/test_containers_integration_tests/controllers/console/app/test_workflow_draft_variable.py
@@ -6,7 +6,7 @@ from flask.testing import FlaskClient
 from sqlalchemy import select
 from sqlalchemy.orm import Session
 
-from dify_graph.constants import CONVERSATION_VARIABLE_NODE_ID, ENVIRONMENT_VARIABLE_NODE_ID
+from core.workflow.variable_prefixes import CONVERSATION_VARIABLE_NODE_ID, ENVIRONMENT_VARIABLE_NODE_ID
 from dify_graph.variables.segments import StringSegment
 from factories.variable_factory import segment_to_variable
 from models import Workflow
diff --git a/api/tests/test_containers_integration_tests/repositories/test_sqlalchemy_execution_extra_content_repository.py b/api/tests/test_containers_integration_tests/repositories/test_sqlalchemy_execution_extra_content_repository.py
index ed998c9ed0..e9faa319c2 100644
--- a/api/tests/test_containers_integration_tests/repositories/test_sqlalchemy_execution_extra_content_repository.py
+++ b/api/tests/test_containers_integration_tests/repositories/test_sqlalchemy_execution_extra_content_repository.py
@@ -270,7 +270,7 @@ def _create_recipient(
 
 
 def _create_delivery(session: Session, *, form_id: str) -> HumanInputDelivery:
-    from dify_graph.nodes.human_input.enums import DeliveryMethodType
+    from core.workflow.human_input_compat import DeliveryMethodType
     from models.human_input import ConsoleDeliveryPayload
 
     delivery = HumanInputDelivery(