diff --git a/app/node_replace_manager.py b/app/node_replace_manager.py
new file mode 100644
index 000000000..3b1b7ab36
--- /dev/null
+++ b/app/node_replace_manager.py
@@ -0,0 +1,23 @@
+from __future__ import annotations
+
+from aiohttp import web
+
+from typing import TYPE_CHECKING
+if TYPE_CHECKING:
+    from comfy_api.latest._node_replace import NodeReplace
+
+REGISTERED_NODE_REPLACEMENTS: dict[str, list[NodeReplace]] = {}
+
+def register_node_replacement(node_replace: NodeReplace):
+    REGISTERED_NODE_REPLACEMENTS.setdefault(node_replace.old_node_id, []).append(node_replace)
+
+def registered_as_dict():
+    return {
+        k: [v.as_dict() for v in v_list] for k, v_list in REGISTERED_NODE_REPLACEMENTS.items()
+    }
+
+class NodeReplaceManager:
+    def add_routes(self, routes):
+        @routes.get("/node_replacements")
+        async def get_node_replacements(request):
+            return web.json_response(registered_as_dict())
diff --git a/comfy_api/latest/_node_replace.py b/comfy_api/latest/_node_replace.py
index 4703937d9..b8278d09d 100644
--- a/comfy_api/latest/_node_replace.py
+++ b/comfy_api/latest/_node_replace.py
@@ -1,6 +1,13 @@
 from __future__ import annotations
 
 from typing import Any
+import app.node_replace_manager
+
+def register_node_replacement(node_replace: NodeReplace):
+    """
+    Register node replacement.
+    """
+    app.node_replace_manager.register_node_replacement(node_replace)
 
 
 class NodeReplace:
@@ -12,8 +19,8 @@ class NodeReplace:
     def __init__(self,
         new_node_id: str,
         old_node_id: str,
-        input_mapping: list[InputMap],
-        output_mapping: list[OutputMap],
+        input_mapping: list[InputMap] | None=None,
+        output_mapping: list[OutputMap] | None=None,
     ):
         self.new_node_id = new_node_id
         self.old_node_id = old_node_id
@@ -27,8 +34,8 @@ class NodeReplace:
         return {
             "new_node_id": self.new_node_id,
             "old_node_id": self.old_node_id,
-            "input_mapping": [m.as_dict() for m in self.input_mapping],
-            "output_mapping": [m.as_dict() for m in self.output_mapping],
+            "input_mapping": [m.as_dict() for m in self.input_mapping] if self.input_mapping else None,
+            "output_mapping": [m.as_dict() for m in self.output_mapping] if self.output_mapping else None,
         }
 
 
diff --git a/server.py b/server.py
index 1888745b7..8da28912a 100644
--- a/server.py
+++ b/server.py
@@ -40,6 +40,7 @@ from app.user_manager import UserManager
 from app.model_manager import ModelFileManager
 from app.custom_node_manager import CustomNodeManager
 from app.subgraph_manager import SubgraphManager
+from app.node_replace_manager import NodeReplaceManager
 from typing import Optional, Union
 from api_server.routes.internal.internal_routes import InternalRoutes
 from protocol import BinaryEventTypes
@@ -204,6 +205,7 @@ class PromptServer():
         self.model_file_manager = ModelFileManager()
         self.custom_node_manager = CustomNodeManager()
         self.subgraph_manager = SubgraphManager()
+        self.node_replace_manager = NodeReplaceManager()
         self.internal_routes = InternalRoutes(self)
         self.supports = ["custom_nodes_from_web"]
         self.prompt_queue = execution.PromptQueue(self)
@@ -992,6 +994,7 @@ class PromptServer():
         self.model_file_manager.add_routes(self.routes)
         self.custom_node_manager.add_routes(self.routes, self.app, nodes.LOADED_MODULE_DIRS.items())
         self.subgraph_manager.add_routes(self.routes, nodes.LOADED_MODULE_DIRS.items())
+        self.node_replace_manager.add_routes(self.routes)
         self.app.add_subapp('/internal', self.internal_routes.get_app())
 
         # Prefix every route with /api for easier matching for delegation.