### What problem does this PR solve?
Fix MCP cannot handle empty Auth field properly, then result in
```bash
2025-11-05 11:10:41,919 INFO 51209 Negotiated protocol version: 2025-06-18
2025-11-05 11:10:41,920 INFO 51209 client_session initialized successfully
2025-11-05 11:10:41,994 INFO 51209 127.0.0.1 - - [05/Nov/2025 11:10:41] "GET /api/v1/datasets?page=1&page_size=1000&orderby=create_time&desc=True HTTP/1.1" 200 -
2025-11-05 11:10:41,999 INFO 51209 Want to clean up 1 MCP sessions
2025-11-05 11:10:42,000 INFO 51209 1 MCP sessions has been cleaned up. 0 in global context.
2025-11-05 11:10:42,001 INFO 51209 127.0.0.1 - - [05/Nov/2025 11:10:42] "POST /v1/mcp_server/test_mcp HTTP/1.1" 200 -
2025-11-05 11:11:30,441 INFO 51209 Negotiated protocol version: 2025-06-18
2025-11-05 11:11:30,442 INFO 51209 client_session initialized successfully
2025-11-05 11:11:30,520 INFO 51209 127.0.0.1 - - [05/Nov/2025 11:11:30] "GET /api/v1/datasets?page=1&page_size=1000&orderby=create_time&desc=True HTTP/1.1" 200 -
2025-11-05 11:11:30,525 INFO 51209 Want to clean up 1 MCP sessions
2025-11-05 11:11:30,526 INFO 51209 1 MCP sessions has been cleaned up. 0 in global context.
2025-11-05 11:11:30,527 INFO 51209 127.0.0.1 - - [05/Nov/2025 11:11:30] "POST /v1/mcp_server/test_mcp HTTP/1.1" 200 -
2025-11-05 11:11:31,476 INFO 51209 Negotiated protocol version: 2025-06-18
2025-11-05 11:11:31,476 INFO 51209 client_session initialized successfully
2025-11-05 11:11:31,549 INFO 51209 127.0.0.1 - - [05/Nov/2025 11:11:31] "GET /api/v1/datasets?page=1&page_size=1000&orderby=create_time&desc=True HTTP/1.1" 200 -
2025-11-05 11:11:31,552 INFO 51209 Want to clean up 1 MCP sessions
2025-11-05 11:11:31,553 INFO 51209 1 MCP sessions has been cleaned up. 0 in global context.
2025-11-05 11:11:31,554 INFO 51209 127.0.0.1 - - [05/Nov/2025 11:11:31] "POST /v1/mcp_server/test_mcp HTTP/1.1" 200 -
2025-11-05 11:11:51,930 ERROR 51209 unhandled errors in a TaskGroup (1 sub-exception)
+ Exception Group Traceback (most recent call last):
| File "/home/xxxxxxxxx/workspace/ragflow/rag/utils/mcp_tool_call_conn.py", line 86, in _mcp_server_loop
| async with streamablehttp_client(url, headers) as (read_stream, write_stream, _):
| File "/home/xxxxxxxxx/.local/share/uv/python/cpython-3.10.16-linux-x86_64-gnu/lib/python3.10/contextlib.py", line 217, in __aexit__
| await self.gen.athrow(typ, value, traceback)
| File "/home/xxxxxxxxx/workspace/ragflow/.venv/lib/python3.10/site-packages/mcp/client/streamable_http.py", line 478, in streamablehttp_client
| async with anyio.create_task_group() as tg:
| File "/home/xxxxxxxxx/workspace/ragflow/.venv/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 781, in __aexit__
| raise BaseExceptionGroup(
| exceptiongroup.ExceptionGroup: unhandled errors in a TaskGroup (1 sub-exception)
+-+---------------- 1 ----------------
| Traceback (most recent call last):
| File "/home/xxxxxxxxx/workspace/ragflow/.venv/lib/python3.10/site-packages/mcp/client/streamable_http.py", line 409, in handle_request_async
| await self._handle_post_request(ctx)
| File "/home/xxxxxxxxx/workspace/ragflow/.venv/lib/python3.10/site-packages/mcp/client/streamable_http.py", line 278, in _handle_post_request
| response.raise_for_status()
| File "/home/xxxxxxxxx/workspace/ragflow/.venv/lib/python3.10/site-packages/httpx/_models.py", line 829, in raise_for_status
| raise HTTPStatusError(message, request=request, response=self)
| httpx.HTTPStatusError: Server error '502 Bad Gateway' for url 'http://192.168.1.38:9382/mcp'
| For more information check: https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/502
+------------------------------------
2025-11-05 11:11:51,942 ERROR 51209 Error fetching tools from MCP server: streamable-http: http://192.168.1.38:9382/mcp
Traceback (most recent call last):
File "/home/xxxxxxxxx/workspace/ragflow/rag/utils/mcp_tool_call_conn.py", line 168, in get_tools
return future.result(timeout=timeout)
File "/home/xxxxxxxxx/.local/share/uv/python/cpython-3.10.16-linux-x86_64-gnu/lib/python3.10/concurrent/futures/_base.py", line 458, in result
return self.__get_result()
File "/home/xxxxxxxxx/.local/share/uv/python/cpython-3.10.16-linux-x86_64-gnu/lib/python3.10/concurrent/futures/_base.py", line 403, in __get_result
raise self._exception
File "<@beartype(rag.utils.mcp_tool_call_conn.MCPToolCallSession._get_tools_from_mcp_server) at 0x7d58f02e2c20>", line 40, in _get_tools_from_mcp_server
File "/home/xxxxxxxxx/workspace/ragflow/rag/utils/mcp_tool_call_conn.py", line 160, in _get_tools_from_mcp_server
result: ListToolsResult = await self._call_mcp_server("list_tools", timeout=timeout)
File "<@beartype(rag.utils.mcp_tool_call_conn.MCPToolCallSession._call_mcp_server) at 0x7d58f02e2b00>", line 63, in _call_mcp_server
File "/home/xxxxxxxxx/workspace/ragflow/rag/utils/mcp_tool_call_conn.py", line 139, in _call_mcp_server
raise result
ValueError: Connection failed (possibly due to auth error). Please check authentication settings first
2025-11-05 11:11:51,943 ERROR 51209 Test MCP error: Connection failed (possibly due to auth error). Please check authentication settings first
Traceback (most recent call last):
File "/home/xxxxxxxxx/workspace/ragflow/api/apps/mcp_server_app.py", line 429, in test_mcp
tools = tool_call_session.get_tools(timeout)
File "<@beartype(rag.utils.mcp_tool_call_conn.MCPToolCallSession.get_tools) at 0x7d58f02e2cb0>", line 40, in get_tools
File "/home/xxxxxxxxx/workspace/ragflow/rag/utils/mcp_tool_call_conn.py", line 168, in get_tools
return future.result(timeout=timeout)
File "/home/xxxxxxxxx/.local/share/uv/python/cpython-3.10.16-linux-x86_64-gnu/lib/python3.10/concurrent/futures/_base.py", line 458, in result
return self.__get_result()
File "/home/xxxxxxxxx/.local/share/uv/python/cpython-3.10.16-linux-x86_64-gnu/lib/python3.10/concurrent/futures/_base.py", line 403, in __get_result
raise self._exception
File "<@beartype(rag.utils.mcp_tool_call_conn.MCPToolCallSession._get_tools_from_mcp_server) at 0x7d58f02e2c20>", line 40, in _get_tools_from_mcp_server
File "/home/xxxxxxxxx/workspace/ragflow/rag/utils/mcp_tool_call_conn.py", line 160, in _get_tools_from_mcp_server
result: ListToolsResult = await self._call_mcp_server("list_tools", timeout=timeout)
File "<@beartype(rag.utils.mcp_tool_call_conn.MCPToolCallSession._call_mcp_server) at 0x7d58f02e2b00>", line 63, in _call_mcp_server
File "/home/xxxxxxxxx/workspace/ragflow/rag/utils/mcp_tool_call_conn.py", line 139, in _call_mcp_server
raise result
ValueError: Connection failed (possibly due to auth error). Please check authentication settings first
2025-11-05 11:11:51,944 INFO 51209 Want to clean up 1 MCP sessions
2025-11-05 11:11:51,945 INFO 51209 1 MCP sessions has been cleaned up. 0 in global context.
2025-11-05 11:11:51,946 INFO 51209 127.0.0.1 - - [05/Nov/2025 11:11:51] "POST /v1/mcp_server/test_mcp HTTP/1.1" 200 -
2025-11-05 11:12:20,484 INFO 51209 Negotiated protocol version: 2025-06-18
2025-11-05 11:12:20,485 INFO 51209 client_session initialized successfully
2025-11-05 11:12:20,570 INFO 51209 127.0.0.1 - - [05/Nov/2025 11:12:20] "GET /api/v1/datasets?page=1&page_size=1000&orderby=create_time&desc=True HTTP/1.1" 200 -
2025-11-05 11:12:20,573 INFO 51209 Want to clean up 1 MCP sessions
2025-11-05 11:12:20,574 INFO 51209 1 MCP sessions has been cleaned up. 0 in global context.
2025-11-05 11:12:20,575 INFO 51209 127.0.0.1 - - [05/Nov/2025 11:12:20] "POST /v1/mcp_server/test_mcp HTTP/1.1" 200 -
2025-11-05 11:15:02,119 INFO 51209 127.0.0.1 - - [05/Nov/2025 11:15:02] "GET /api/v1/datasets?page=1&page_size=1000&orderby=create_time&desc=True HTTP/1.1" 200 -
2025-11-05 11:16:24,967 INFO 51209 127.0.0.1 - - [05/Nov/2025 11:16:24] "GET /api/v1/datasets?page=1&page_size=1000&orderby=create_time&desc=True HTTP/1.1" 200 -
2025-11-05 11:30:24,284 ERROR 51209 Task was destroyed but it is pending!
task: <Task pending name='Task-58' coro=<MCPToolCallSession._mcp_server_loop() running at <@beartype(rag.utils.mcp_tool_call_conn.MCPToolCallSession._mcp_server_loop) at 0x7d58f02e29e0>:11> wait_for=<Future pending cb=[Task.task_wakeup()]> cb=[_chain_future.<locals>._call_set_state() at /home/xxxxxxxxx/.local/share/uv/python/cpython-3.10.16-linux-x86_64-gnu/lib/python3.10/asyncio/futures.py:392]>
2025-11-05 11:30:24,285 ERROR 51209 Task was destroyed but it is pending!
task: <Task pending name='Task-67' coro=<Queue.get() running at /home/xxxxxxxxx/.local/share/uv/python/cpython-3.10.16-linux-x86_64-gnu/lib/python3.10/asyncio/queues.py:159> wait_for=<Future pending cb=[Task.task_wakeup()]> cb=[_release_waiter(<Future pendi...ask_wakeup()]>)() at /home/xxxxxxxxx/.local/share/uv/python/cpython-3.10.16-linux-x86_64-gnu/lib/python3.10/asyncio/tasks.py:387]>
Exception ignored in: <coroutine object Queue.get at 0x7d585480ace0>
Traceback (most recent call last):
File "/home/xxxxxxxxx/.local/share/uv/python/cpython-3.10.16-linux-x86_64-gnu/lib/python3.10/asyncio/queues.py", line 161, in get
getter.cancel() # Just in case getter is not done yet.
File "/home/xxxxxxxxx/.local/share/uv/python/cpython-3.10.16-linux-x86_64-gnu/lib/python3.10/asyncio/base_events.py", line 753, in call_soon
self._check_closed()
File "/home/xxxxxxxxx/.local/share/uv/python/cpython-3.10.16-linux-x86_64-gnu/lib/python3.10/asyncio/base_events.py", line 515, in _check_closed
raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed
```
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)
### What problem does this PR solve?
#9082#6365
<u> **WARNING: it's not compatible with the older version of `Agent`
module, which means that `Agent` from older versions can not work
anymore.**</u>
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
