diff --git a/metagpt/actions/design_api.py b/metagpt/actions/design_api.py
index 981e1405a..b0a6a2861 100644
--- a/metagpt/actions/design_api.py
+++ b/metagpt/actions/design_api.py
@@ -62,7 +62,7 @@ class WriteDesign(Action):
         *,
         user_requirement: str = "",
         prd_filename: str = "",
-        exists_design_filename: str = "",
+        legacy_design_filename: str = "",
         extra_info: str = "",
         output_path: str = "",
         **kwargs,
@@ -73,7 +73,7 @@ class WriteDesign(Action):
         Args:
             user_requirement (str): The user's requirements for the system design.
             prd_filename (str, optional): The filename of the Product Requirement Document (PRD).
-            exists_design_filename (str, optional): The filename of the existing design document.
+            legacy_design_filename (str, optional): The filename of the legacy design document.
             extra_info (str, optional): Additional information to be included in the system design.
             output_path (str, optional): The output path where the system design should be saved.
 
@@ -92,9 +92,9 @@ class WriteDesign(Action):
             # Modify an exists system design.
             >>> user_requirement = "Your user requirements"
             >>> extra_info = "Your extra information"
-            >>> exists_design_filename = "/path/to/exists/design/filename"
+            >>> legacy_design_filename = "/path/to/exists/design/filename"
             >>> action = WriteDesign()
-            >>> result = await action.run(user_requirement=user_requirement, extra_info=extra_info, exists_design_filename=exists_design_filename)
+            >>> result = await action.run(user_requirement=user_requirement, extra_info=extra_info, legacy_design_filename=legacy_design_filename)
             >>> print(result.content)
             The design is balabala...
 
@@ -111,9 +111,9 @@ class WriteDesign(Action):
             >>> user_requirement = "Your user requirements"
             >>> extra_info = "Your extra information"
             >>> prd_filename = "/path/to/prd/filename"
-            >>> exists_design_filename = "/path/to/exists/design/filename"
+            >>> legacy_design_filename = "/path/to/exists/design/filename"
             >>> action = WriteDesign()
-            >>> result = await action.run(user_requirement=user_requirement, extra_info=extra_info, exists_design_filename=exists_design_filename, prd_filename=prd_filename)
+            >>> result = await action.run(user_requirement=user_requirement, extra_info=extra_info, legacy_design_filename=legacy_design_filename, prd_filename=prd_filename)
             >>> print(result.content)
             The design is balabala...
 
@@ -129,10 +129,10 @@ class WriteDesign(Action):
             # Modify an exists system design and save to the directory.
             >>> user_requirement = "Your user requirements"
             >>> extra_info = "Your extra information"
-            >>> exists_design_filename = "/path/to/exists/design/filename"
+            >>> legacy_design_filename = "/path/to/exists/design/filename"
             >>> output_path = "/path/to/save/"
             >>> action = WriteDesign()
-            >>> result = await action.run(user_requirement=user_requirement, extra_info=extra_info, exists_design_filename=exists_design_filename)
+            >>> result = await action.run(user_requirement=user_requirement, extra_info=extra_info, legacy_design_filename=legacy_design_filename)
             >>> print(result.content)
             System Design filename: "/path/to/design/filename"
 
@@ -150,10 +150,10 @@ class WriteDesign(Action):
             >>> user_requirement = "Your user requirements"
             >>> extra_info = "Your extra information"
             >>> prd_filename = "/path/to/prd/filename"
-            >>> exists_design_filename = "/path/to/exists/design/filename"
+            >>> legacy_design_filename = "/path/to/exists/design/filename"
             >>> output_path = "/path/to/save/"
             >>> action = WriteDesign()
-            >>> result = await action.run(user_requirement=user_requirement, extra_info=extra_info, exists_design_filename=exists_design_filename, prd_filename=prd_filename)
+            >>> result = await action.run(user_requirement=user_requirement, extra_info=extra_info, legacy_design_filename=legacy_design_filename, prd_filename=prd_filename)
             >>> print(result.content)
             System Design filename: "/path/to/design/filename"
         """
@@ -161,7 +161,7 @@ class WriteDesign(Action):
             return await self._execute_api(
                 user_requirement=user_requirement,
                 prd_filename=prd_filename,
-                exists_design_filename=exists_design_filename,
+                legacy_design_filename=legacy_design_filename,
                 extra_info=extra_info,
                 output_path=output_path,
             )
@@ -266,7 +266,7 @@ class WriteDesign(Action):
         self,
         user_requirement: str = "",
         prd_filename: str = "",
-        exists_design_filename: str = "",
+        legacy_design_filename: str = "",
         extra_info: str = "",
         output_path: str = "",
     ) -> AIMessage:
@@ -276,11 +276,11 @@ class WriteDesign(Action):
         if prd_filename:
             prd_content = await aread(filename=prd_filename)
             context += to_markdown_code_block(prd_content)
-        if not exists_design_filename:
+        if not legacy_design_filename:
             node = await self._new_system_design(context=context)
             design = Document(content=node.instruct_content.model_dump_json())
         else:
-            old_design_content = await aread(filename=exists_design_filename)
+            old_design_content = await aread(filename=legacy_design_filename)
             design = await self._merge(
                 prd_doc=Document(content=context), system_design_doc=Document(content=old_design_content)
             )
diff --git a/metagpt/actions/write_prd.py b/metagpt/actions/write_prd.py
index de3bcde84..58db97c75 100644
--- a/metagpt/actions/write_prd.py
+++ b/metagpt/actions/write_prd.py
@@ -83,7 +83,7 @@ class WritePRD(Action):
         *,
         user_requirement: str = "",
         output_path: str = "",
-        exists_prd_filename: str = "",
+        legacy_prd_filename: str = "",
         extra_info: str = "",
         **kwargs,
     ) -> AIMessage:
@@ -93,7 +93,7 @@ class WritePRD(Action):
         Args:
             user_requirement (str): A string detailing the user's requirements.
             output_path (str, optional): The file path where the output document should be saved. Defaults to "".
-            exists_prd_filename (str, optional): The file path of an existing Product Requirement Document to use as a reference. Defaults to "".
+            legacy_prd_filename (str, optional): The file path of the legacy Product Requirement Document to use as a reference. Defaults to "".
             extra_info (str, optional): Additional information to include in the document. Defaults to "".
             **kwargs: Additional keyword arguments.
 
@@ -112,9 +112,9 @@ class WritePRD(Action):
             # Modify a exists PRD(Product Requirement Document)
             >>> user_requirement = "YOUR REQUIREMENTS"
             >>> extra_info = "YOUR EXTRA INFO"
-            >>> exists_prd_filename = "/path/to/exists/prd_filename"
+            >>> legacy_prd_filename = "/path/to/exists/prd_filename"
             >>> write_prd = WritePRD()
-            >>> result = await write_prd.run(user_requirement=user_requirement, extra_info=extra_info, exists_prd_filename=exists_prd_filename)
+            >>> result = await write_prd.run(user_requirement=user_requirement, extra_info=extra_info, legacy_prd_filename=legacy_prd_filename)
             >>> print(result.content)
             The PRD is about balabala...
 
@@ -130,10 +130,10 @@ class WritePRD(Action):
             # Modify a exists PRD(Product Requirement Document) and save to the directory.
             >>> user_requirement = "YOUR REQUIREMENTS"
             >>> extra_info = "YOUR EXTRA INFO"
-            >>> exists_prd_filename = "/path/to/exists/prd_filename"
+            >>> legacy_prd_filename = "/path/to/exists/prd_filename"
             >>> output_path = "/path/to/prd/directory/"
             >>> write_prd = WritePRD()
-            >>> result = await write_prd.run(user_requirement=user_requirement, extra_info=extra_info, exists_prd_filename=exists_prd_filename, output_path=output_path)
+            >>> result = await write_prd.run(user_requirement=user_requirement, extra_info=extra_info, legacy_prd_filename=legacy_prd_filename, output_path=output_path)
             >>> print(result.content)
             PRD filename: "/path/to/prd/directory/213434ad.json"
 
@@ -142,7 +142,7 @@ class WritePRD(Action):
             return await self._execute_api(
                 user_requirement=user_requirement,
                 output_path=output_path,
-                exists_prd_filename=exists_prd_filename,
+                legacy_prd_filename=legacy_prd_filename,
                 extra_info=extra_info,
             )
 
@@ -306,18 +306,18 @@ class WritePRD(Action):
             self.repo.git_repo.rename_root(self.project_name)
 
     async def _execute_api(
-        self, user_requirement: str, output_path: str, exists_prd_filename: str, extra_info: str
+        self, user_requirement: str, output_path: str, legacy_prd_filename: str, extra_info: str
     ) -> AIMessage:
         content = to_markdown_code_block(val=user_requirement, type_="text")
         if extra_info:
             content += to_markdown_code_block(val=extra_info)
 
         req = Document(content=content)
-        if not exists_prd_filename:
+        if not legacy_prd_filename:
             node = await self._new_prd(requirement=req.content)
             new_prd = Document(content=node.instruct_content.model_dump_json())
         else:
-            content = await aread(filename=exists_prd_filename)
+            content = await aread(filename=legacy_prd_filename)
             old_prd = Document(content=content)
             new_prd = await self._merge(req=req, related_doc=old_prd)
 
diff --git a/tests/metagpt/actions/test_design_api.py b/tests/metagpt/actions/test_design_api.py
index 1351b418a..0a792fb15 100644
--- a/tests/metagpt/actions/test_design_api.py
+++ b/tests/metagpt/actions/test_design_api.py
@@ -55,7 +55,7 @@ async def test_design(context):
 
 
 @pytest.mark.parametrize(
-    ("user_requirement", "prd_filename", "exists_design_filename"),
+    ("user_requirement", "prd_filename", "legacy_design_filename"),
     [
         ("我们需要一个音乐播放器，它应该有播放、暂停、上一曲、下一曲等功能。", None, None),
         ("write 2048 game", str(METAGPT_ROOT / "tests/data/prd.json"), None),
@@ -67,10 +67,10 @@ async def test_design(context):
     ],
 )
 @pytest.mark.asyncio
-async def test_design_api(context, user_requirement, prd_filename, exists_design_filename):
+async def test_design_api(context, user_requirement, prd_filename, legacy_design_filename):
     action = WriteDesign()
     result = await action.run(
-        user_requirement=user_requirement, prd_filename=prd_filename, exists_design_filename=exists_design_filename
+        user_requirement=user_requirement, prd_filename=prd_filename, legacy_design_filename=legacy_design_filename
     )
     assert isinstance(result, AIMessage)
     assert result.content
@@ -79,7 +79,7 @@ async def test_design_api(context, user_requirement, prd_filename, exists_design
 
 
 @pytest.mark.parametrize(
-    ("user_requirement", "prd_filename", "exists_design_filename"),
+    ("user_requirement", "prd_filename", "legacy_design_filename"),
     [
         ("我们需要一个音乐播放器，它应该有播放、暂停、上一曲、下一曲等功能。", None, None),
         ("write 2048 game", str(METAGPT_ROOT / "tests/data/prd.json"), None),
@@ -91,12 +91,12 @@ async def test_design_api(context, user_requirement, prd_filename, exists_design
     ],
 )
 @pytest.mark.asyncio
-async def test_design_api_dir(context, user_requirement, prd_filename, exists_design_filename):
+async def test_design_api_dir(context, user_requirement, prd_filename, legacy_design_filename):
     action = WriteDesign()
     result = await action.run(
         user_requirement=user_requirement,
         prd_filename=prd_filename,
-        exists_design_filename=exists_design_filename,
+        legacy_design_filename=legacy_design_filename,
         output_path=context.config.project_path,
     )
     assert isinstance(result, AIMessage)
diff --git a/tests/metagpt/actions/test_write_prd.py b/tests/metagpt/actions/test_write_prd.py
index 8cbc01716..93a1b150c 100644
--- a/tests/metagpt/actions/test_write_prd.py
+++ b/tests/metagpt/actions/test_write_prd.py
@@ -91,7 +91,7 @@ async def test_write_prd_api(context):
 
     legacy_prd_filename = result.instruct_content.changed_prd_filenames[-1]
 
-    result = await action.run(user_requirement="Add moving enemy.", exists_prd_filename=legacy_prd_filename)
+    result = await action.run(user_requirement="Add moving enemy.", legacy_prd_filename=legacy_prd_filename)
     assert isinstance(result, AIMessage)
     assert result.content
     m = json.loads(result.content)
@@ -100,7 +100,7 @@ async def test_write_prd_api(context):
     result = await action.run(
         user_requirement="Add moving enemy.",
         output_path=str(context.config.project_path),
-        exists_prd_filename=legacy_prd_filename,
+        legacy_prd_filename=legacy_prd_filename,
     )
     assert isinstance(result, AIMessage)
     assert result.content