diff --git a/.well-known/metagpt_oas3_api.yaml b/.well-known/metagpt_oas3_api.yaml
index 7a0058b50..7ae10579c 100644
--- a/.well-known/metagpt_oas3_api.yaml
+++ b/.well-known/metagpt_oas3_api.yaml
@@ -7,9 +7,8 @@ servers:
   - url: "/oas3"
     variables:
       port:
-        enum:
-          - '8080'
         default: '8080'
+        description: HTTP service port
 
 paths:
   /tts/azsure:
diff --git a/metagpt/tools/metagpt_oas3_api_svc.py b/metagpt/tools/metagpt_oas3_api_svc.py
index aa5f50cb2..277d41dfb 100644
--- a/metagpt/tools/metagpt_oas3_api_svc.py
+++ b/metagpt/tools/metagpt_oas3_api_svc.py
@@ -6,16 +6,41 @@
 @File    : metagpt_oas3_api_svc.py
 @Desc    : MetaGPT OpenAPI Specification 3.0 REST API service
 """
+import asyncio
 from pathlib import Path
 import sys
+
 import connexion
+
 sys.path.append(str(Path(__file__).resolve().parent.parent.parent))  # fix-bug: No module named 'metagpt'
 from metagpt.utils.common import initialize_environment
 
-if __name__ == "__main__":
+
+def oas_http_svc():
+    """Start the OAS 3.0 OpenAPI HTTP service"""
     initialize_environment()
 
-    app = connexion.AioHttpApp(__name__, specification_dir='../../.well-known/')
+    app = connexion.FlaskApp(__name__, specification_dir='../../.well-known/')
     app.add_api("metagpt_oas3_api.yaml")
     app.add_api("openapi.yaml")
     app.run(port=8080)
+
+
+async def async_main():
+    """Start the OAS 3.0 OpenAPI HTTP service in the background."""
+    loop = asyncio.get_event_loop()
+    loop.run_in_executor(None, oas_http_svc)
+
+    # TODO: replace following codes:
+    while True:
+        await asyncio.sleep(1)
+        print("sleep")
+
+
+def main():
+    oas_http_svc()
+
+
+if __name__ == "__main__":
+    # asyncio.run(async_main())
+    main()