Force APIRouter.include_router to propagate Mount paths instead of dropping them. (#1)

This change ensures that mounted ASGI applications (such as Flask apps wrapped in WSGIMiddleware) are not dropped when `APIRouter.include_router` is called.

Previously, while the initial load in `ExtensionLoader` worked as expected, the `Mount` objects were ignored by FastAPI's default inclusion logic. This caused the mounted elements to be lost during the final application assembly, resulting in 404 errors for the Flask routes.

This fix overrides the inclusion logic to manually propagate `Mount` objects downstream.

Author: deeleeramone

openbb_platform/core/openbb_core/api/app_loader.py

@@ -7,6 +7,7 @@
 from openbb_core.app.router import RouterLoader
 from openbb_core.provider.utils.errors import EmptyDataError, UnauthorizedError
 from pydantic import ValidationError
+from starlette.routing import Mount
 
 
 class AppLoader:
@@ -15,8 +16,30 @@ class AppLoader:
     @staticmethod
     def add_routers(app: FastAPI, routers: list[APIRouter | None], prefix: str):
         """Add routers."""
+
+        def _join_paths(p1: str, p2: str) -> str:
+            if not p1:
+                return p2 or "/"
+            if not p2:
+                return p1 or "/"
+            joined = p1.rstrip("/") + "/" + p2.lstrip("/")
+            return joined.rstrip("/") or "/"
+
         for router in routers:
             if router:
+                # FastAPI's include_router doesn't propagate Starlette Mount routes.
+                # If an APIRouter contains mounted sub-apps (e.g. WSGIMiddleware for Flask),
+                # mount them directly on the FastAPI app with the same prefix.
+                for route in getattr(router, "routes", []):
+                    if not isinstance(route, Mount):
+                        continue
+                    mount_path = _join_paths(prefix, route.path)
+                    if any(
+                        isinstance(existing, Mount) and existing.path == mount_path
+                        for existing in app.router.routes
+                    ):
+                        continue
+                    app.mount(mount_path, route.app, name=route.name)
                 app.include_router(router=router, prefix=prefix)
 
     @staticmethod

openbb_platform/core/openbb_core/api/router/commands.py

@@ -23,6 +23,7 @@
 from openbb_core.env import Env
 from openbb_core.provider.utils.helpers import to_snake_case
 from pydantic import BaseModel
+from starlette.routing import Mount
 from typing_extensions import ParamSpec
 
 try:
@@ -349,7 +350,18 @@ def add_command_map(command_runner: CommandRunner, api_router: APIRouter) -> Non
     plugins_router = RouterLoader.from_extensions()
 
     for route in plugins_router.api_router.routes:
-        route.endpoint = build_api_wrapper(command_runner=command_runner, route=route)  # type: ignore # noqa
+        if isinstance(route, APIRoute):
+            route.endpoint = build_api_wrapper(command_runner=command_runner, route=route)  # type: ignore # noqa
+            continue
+        # Mounted sub-apps (e.g. WSGIMiddleware for Flask) are Starlette Mount routes.
+        # APIRouter.include_router will not carry these over, so we mount them manually.
+        if isinstance(route, Mount):
+            if any(
+                isinstance(existing, Mount) and existing.path == route.path
+                for existing in api_router.routes
+            ):
+                continue
+            api_router.mount(route.path, route.app, name=route.name)
     api_router.include_router(router=plugins_router.api_router)
 
 

openbb_platform/core/openbb_core/app/router.py

@@ -15,6 +15,7 @@
 )
 
 from fastapi import APIRouter, Depends
+from fastapi.routing import APIRoute
 from openbb_core.app.deprecation import DeprecationSummary, OpenBBDeprecationWarning
 from openbb_core.app.extension_loader import ExtensionLoader
 from openbb_core.app.model.abstract.warning import OpenBBWarning
@@ -28,6 +29,7 @@
 )
 from openbb_core.env import Env
 from pydantic import BaseModel
+from starlette.routing import Mount
 from typing_extensions import ParamSpec
 
 P = ParamSpec("P")
@@ -182,6 +184,29 @@ def include_router(
             prefix=prefix,
             tags=tags,  # type: ignore
         )
+
+        # FastAPI's APIRouter.include_router only includes APIRoute instances.
+        # Starlette Mount routes (used by .mount, e.g. for WSGIMiddleware) must
+        # be manually propagated, otherwise mounted apps silently disappear.
+        def _join_paths(p1: str, p2: str) -> str:
+            if not p1:
+                return p2 or "/"
+            if not p2:
+                return p1 or "/"
+            joined = p1.rstrip("/") + "/" + p2.lstrip("/")
+            return joined.rstrip("/") or "/"
+
+        for route in router.api_router.routes:
+            if not isinstance(route, Mount):
+                continue
+            mount_path = _join_paths(prefix, route.path)
+            if any(
+                isinstance(existing, Mount) and existing.path == mount_path
+                for existing in self._api_router.routes
+            ):
+                continue
+            self._api_router.mount(mount_path, route.app, name=route.name)
+
         name = prefix if prefix else router.prefix
         self._routers[name.strip("/")] = router
 
@@ -426,7 +451,11 @@ def get_command_map(
     ) -> dict[str, Callable]:
         """Get command map."""
         api_router = router.api_router
-        command_map = {route.path: route.endpoint for route in api_router.routes}  # type: ignore
+        command_map = {
+            route.path: route.endpoint
+            for route in api_router.routes
+            if isinstance(route, APIRoute)
+        }
         return command_map
 
     @staticmethod
@@ -440,6 +469,8 @@ def get_provider_coverage(
 
         coverage_map: dict[Any, Any] = {}
         for route in api_router.routes:
+            if not isinstance(route, APIRoute):
+                continue
             openapi_extra = getattr(route, "openapi_extra", None)
             if openapi_extra:
                 model = openapi_extra.get("model", None)
@@ -471,7 +502,9 @@ def get_command_coverage(
 
         coverage_map: dict[Any, Any] = {}
         for route in api_router.routes:
-            openapi_extra = getattr(route, "openapi_extra")
+            if not isinstance(route, APIRoute):
+                continue
+            openapi_extra = getattr(route, "openapi_extra", None)
             if openapi_extra:
                 model = openapi_extra.get("model", None)
                 if model:
@@ -493,7 +526,9 @@ def get_commands_model(router: Router, sep: str | None = None) -> dict[str, str]
 
         coverage_map: dict[Any, Any] = {}
         for route in api_router.routes:
-            openapi_extra = getattr(route, "openapi_extra")
+            if not isinstance(route, APIRoute):
+                continue
+            openapi_extra = getattr(route, "openapi_extra", None)
             if openapi_extra:
                 model = openapi_extra.get("model", None)
                 if model and hasattr(route, "path"):

openbb_platform/core/tests/app/test_platform_router.py

@@ -18,6 +18,9 @@
     SignatureInspector,
 )
 from pydantic import BaseModel, ConfigDict
+from starlette.applications import Starlette
+from starlette.responses import PlainTextResponse
+from starlette.routing import Mount
 
 
 class MockBaseModel(BaseModel):
@@ -53,6 +56,34 @@ def test_include_router(router):
     assert router.include_router(some_router) is None
 
 
+def test_include_router_propagates_mount() -> None:
+    """Mounted sub-app routes should survive Router.include_router."""
+    child = Router()
+    child.api_router.mount(
+        "/",
+        Starlette(
+            routes=[
+                # A simple mounted route to prove the mount exists.
+                # If Mount isn't propagated, it silently disappears.
+                # (We don't need to issue HTTP requests here.)
+                # noqa: E501
+            ],
+        ),
+    )
+
+    # Mount an app that has at least one route.
+    mounted_app = Starlette()
+    mounted_app.add_route("/health", lambda *_: PlainTextResponse("ok"))
+    child.api_router.routes.clear()
+    child.api_router.mount("/", mounted_app)
+
+    parent = Router()
+    parent.include_router(child, prefix="/flask")
+
+    mount_paths = [r.path for r in parent.api_router.routes if isinstance(r, Mount)]
+    assert "/flask" in mount_paths
+
+
 @pytest.fixture(scope="module")
 def router_loader():
     """Set up router_loader."""