diff --git a/metagpt/actions/prepare_documents.py b/metagpt/actions/prepare_documents.py
index fe954b79c..71c94d25a 100644
--- a/metagpt/actions/prepare_documents.py
+++ b/metagpt/actions/prepare_documents.py
@@ -8,8 +8,6 @@
         RFC 135 2.2.3.5.1.
 """
 
-from pathlib import Path
-
 from metagpt.actions import Action, ActionOutput
 from metagpt.config import CONFIG
 from metagpt.const import DEFAULT_WORKSPACE_ROOT, DOCS_FILE_REPO, REQUIREMENT_FILENAME
@@ -28,11 +26,9 @@ class PrepareDocuments(Action):
             return ActionOutput(content=doc.json(exclue="content"), instruct_content=doc)
 
         # Create and initialize the workspace folder, initialize the Git environment.
-        default_workspace_root = CONFIG.project_path or DEFAULT_WORKSPACE_ROOT
-        default_project_name = CONFIG.project_name or FileRepository.new_filename()
-        default_workdir = Path(default_workspace_root) / default_project_name
+        project_name = CONFIG.project_name or FileRepository.new_filename()
+        workdir = CONFIG.project_path or DEFAULT_WORKSPACE_ROOT / project_name
         CONFIG.git_repo = GitRepository()
-        workdir = Path(CONFIG.WORKDIR) if CONFIG.WORKDIR else default_workdir
         CONFIG.git_repo.open(local_path=workdir, auto_init=True)
 
         # Write the newly added requirements from the main parameter idea to `docs/requirement.txt`.
diff --git a/metagpt/startup.py b/metagpt/startup.py
index de348780b..78f32d556 100644
--- a/metagpt/startup.py
+++ b/metagpt/startup.py
@@ -12,17 +12,18 @@ app = typer.Typer()
 @app.command()
 def startup(
     idea: str = typer.Argument(..., help="Your innovative idea, such as 'Create a 2048 game.'"),
-    investment: float = typer.Option(3.0, help="Dollar amount to invest in the AI company."),
-    n_round: int = typer.Option(5, help="Number of rounds for the simulation."),
-    code_review: bool = typer.Option(True, help="Whether to use code review."),
-    run_tests: bool = typer.Option(False, help="Whether to enable QA for adding & running tests."),
-    implement: bool = typer.Option(True, help="Enable or disable code implementation."),
-    project_name: str = typer.Option("", help="Unique project name, such as 'game_2048'."),
-    inc: bool = typer.Option(False, help="Incremental mode. Use it to coop with existing repo."),
+    investment: float = typer.Option(default=3.0, help="Dollar amount to invest in the AI company."),
+    n_round: int = typer.Option(default=5, help="Number of rounds for the simulation."),
+    code_review: bool = typer.Option(default=True, help="Whether to use code review."),
+    run_tests: bool = typer.Option(default=False, help="Whether to enable QA for adding & running tests."),
+    implement: bool = typer.Option(default=True, help="Enable or disable code implementation."),
+    project_name: str = typer.Option(default="", help="Unique project name, such as 'game_2048'."),
+    inc: bool = typer.Option(default=False, help="Incremental mode. Use it to coop with existing repo."),
     project_path: str = typer.Option(
-        help="Specify the directory path of the old version project to fulfill the " "incremental requirements."
+        default="",
+        help="Specify the directory path of the old version project to fulfill the " "incremental requirements.",
     ),
-    reqa_file: str = typer.Option(help="Specify the source file name for rewriting the quality test code."),
+    reqa_file: str = typer.Option(default="", help="Specify the source file name for rewriting the quality test code."),
 ):
     """Run a startup. Be a boss."""
     from metagpt.roles import (
diff --git a/metagpt/utils/file_repository.py b/metagpt/utils/file_repository.py
index 846bfcd0c..0815bf90a 100644
--- a/metagpt/utils/file_repository.py
+++ b/metagpt/utils/file_repository.py
@@ -54,7 +54,7 @@ class FileRepository:
         """
         pathname = self.workdir / filename
         pathname.parent.mkdir(parents=True, exist_ok=True)
-        async with aiofiles.open(str(pathname), mode="wb") as writer:
+        async with aiofiles.open(str(pathname), mode="w") as writer:
             await writer.write(content)
         logger.info(f"save to: {str(pathname)}")
 
@@ -98,7 +98,7 @@ class FileRepository:
         if not path_name.exists():
             return None
         try:
-            async with aiofiles.open(str(path_name), mode="rb") as reader:
+            async with aiofiles.open(str(path_name), mode="r") as reader:
                 doc.content = await reader.read()
         except FileNotFoundError as e:
             logger.info(f"open {str(path_name)} failed:{e}")