fix: prevent double /v1 in MCP server URL causing 404 authorization failure (#34596)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

api/controllers/console/datasets/datasets.py

@@ -50,6 +50,7 @@ from fields.dataset_fields import (
 from fields.document_fields import document_status_fields
 from graphon.model_runtime.entities.model_entities import ModelType
 from libs.login import current_account_with_tenant, login_required
+from libs.url_utils import normalize_api_base_url
 from models import ApiToken, Dataset, Document, DocumentSegment, UploadFile
 from models.dataset import DatasetPermission, DatasetPermissionEnum
 from models.enums import ApiTokenType, SegmentStatus
@@ -889,7 +890,8 @@ class DatasetApiBaseUrlApi(Resource):
     @login_required
     @account_initialization_required
     def get(self):
-        return {"api_base_url": (dify_config.SERVICE_API_URL or request.host_url.rstrip("/")) + "/v1"}
+        base = dify_config.SERVICE_API_URL or request.host_url.rstrip("/")
+        return {"api_base_url": normalize_api_base_url(base)}
 
 
 @console_ns.route("/datasets/retrieval-setting")

api/controllers/console/workspace/tool_providers.py

@@ -1131,6 +1131,14 @@ class ToolMCPAuthApi(Resource):
             with sessionmaker(db.engine).begin() as session:
                 service = MCPToolManageService(session=session)
                 service.clear_provider_credentials(provider_id=provider_id, tenant_id=tenant_id)
+            parsed = urlparse(server_url)
+            sanitized_url = f"{parsed.scheme}://{parsed.hostname}{parsed.path}"
+            logger.warning(
+                "MCP authorization failed for provider %s (url=%s)",
+                provider_id,
+                sanitized_url,
+                exc_info=True,
+            )
             raise ValueError(f"Failed to connect to MCP server: {e}") from e
 
 

api/core/mcp/client/streamable_client.py

@@ -303,9 +303,16 @@ class StreamableHTTPTransport:
 
             if response.status_code == 404:
                 if isinstance(message.root, JSONRPCRequest):
+                    error_msg = (
+                        f"MCP server URL returned 404 Not Found: {self.url} "
+                        "— verify the server URL is correct and the server is running"
+                        if is_initialization
+                        else "Session terminated by server"
+                    )
                     self._send_session_terminated_error(
                         ctx.server_to_client_queue,
                         message.root.id,
+                        message=error_msg,
                     )
                 return
 
@@ -381,12 +388,13 @@ class StreamableHTTPTransport:
         self,
         server_to_client_queue: ServerToClientQueue,
         request_id: RequestId,
+        message: str = "Session terminated by server",
     ):
         """Send a session terminated error response."""
         jsonrpc_error = JSONRPCError(
             jsonrpc="2.0",
             id=request_id,
-            error=ErrorData(code=32600, message="Session terminated by server"),
+            error=ErrorData(code=32600, message=message),
         )
         session_message = SessionMessage(JSONRPCMessage(jsonrpc_error))
         server_to_client_queue.put(session_message)

api/libs/url_utils.py

@@ -0,0 +1,3 @@
+def normalize_api_base_url(base_url: str) -> str:
+    """Normalize a base URL to always end with /v1, avoiding double /v1 suffixes."""
+    return base_url.rstrip("/").removesuffix("/v1").rstrip("/") + "/v1"

api/models/model.py

@@ -25,6 +25,7 @@ from graphon.enums import WorkflowExecutionStatus
 from graphon.file import FILE_MODEL_IDENTITY, File, FileTransferMethod, FileType
 from graphon.file import helpers as file_helpers
 from libs.helper import generate_string  # type: ignore[import-not-found]
+from libs.url_utils import normalize_api_base_url
 from libs.uuid_utils import uuidv7
 from models.utils.file_input_compat import build_file_from_input_mapping
 
@@ -446,7 +447,8 @@ class App(Base):
 
     @property
     def api_base_url(self) -> str:
-        return (dify_config.SERVICE_API_URL or request.host_url.rstrip("/")) + "/v1"
+        base = dify_config.SERVICE_API_URL or request.host_url.rstrip("/")
+        return normalize_api_base_url(base)
 
     @property
     def tenant(self) -> Tenant | None:

api/tests/unit_tests/controllers/console/datasets/test_datasets.py

@@ -1772,6 +1772,21 @@ class TestDatasetApiBaseUrlApi:
 
         assert response["api_base_url"] == "http://localhost:5000/v1"
 
+    def test_get_api_base_url_no_double_v1(self, app):
+        api = DatasetApiBaseUrlApi()
+        method = unwrap(api.get)
+
+        with (
+            app.test_request_context("/"),
+            patch(
+                "controllers.console.datasets.datasets.dify_config.SERVICE_API_URL",
+                "https://example.com/v1",
+            ),
+        ):
+            response = method(api)
+
+        assert response["api_base_url"] == "https://example.com/v1"
+
 
 class TestDatasetRetrievalSettingApi:
     def test_get_success(self, app):

api/tests/unit_tests/core/mcp/client/test_streamable_http.py

@@ -971,6 +971,23 @@ class TestHandlePostRequestNew:
         assert isinstance(item, SessionMessage)
         assert isinstance(item.message.root, JSONRPCError)
         assert item.message.root.id == 77
+        assert item.message.root.error.message == "Session terminated by server"
+
+    def test_404_on_initialization_includes_url_in_error(self):
+        t = _new_transport(url="http://example.com/mcp/server/abc123/mcp")
+        q: queue.Queue = queue.Queue()
+        msg = _make_request_msg("initialize", 1)
+        ctx = self._make_ctx(t, q, message=msg)
+        mock_resp = MagicMock()
+        mock_resp.status_code = 404
+        ctx.client.stream = self._stream_ctx(mock_resp)
+        t._handle_post_request(ctx)
+        item = q.get_nowait()
+        assert isinstance(item, SessionMessage)
+        assert isinstance(item.message.root, JSONRPCError)
+        assert item.message.root.error.code == 32600
+        assert "404 Not Found" in item.message.root.error.message
+        assert "http://example.com/mcp/server/abc123/mcp" in item.message.root.error.message
 
     def test_404_for_notification_no_error_sent(self):
         t = _new_transport()

web/app/components/tools/mcp/hooks/use-mcp-service-card.ts

@@ -69,7 +69,7 @@ export const useMCPServiceCardState = (
   const serverPublished = !!id
   const serverActivated = status === 'active'
   const serverURL = serverPublished
-    ? `${appInfo.api_base_url.replace('/v1', '')}/mcp/server/${server_code}/mcp`
+    ? `${appInfo.api_base_url.replace(/\/v1$/, '')}/mcp/server/${server_code}/mcp`
     : '***********'
 
   // App state checks