fix(chainlit): serve source downloads from standalone Chainlit app (Ray Serve mode)

openrag/chainlit_api.py

@@ -1,4 +1,5 @@
 from api.middleware.auth import AuthMiddleware
+from api.routers.user.download import router as download_router
 from chainlit.utils import mount_chainlit
 from fastapi import FastAPI
 
@@ -21,4 +22,12 @@ def _get_auth_service(request):
     get_auth_service=_get_auth_service,
 )
 
+# Ray Serve mode runs the API and Chainlit on separate ports. Source previews
+# rewrite their file download links to the browser origin (the Chainlit host),
+# so this standalone Chainlit app must also expose the authorized,
+# partition-checked source-download route (/static/{extract_id}) or those
+# links would 404. In the mounted (/chainlit) deployment the UI shares the
+# API's origin, which already serves this route.
+app.include_router(download_router)
+
 mount_chainlit(app=app, target="./app_front.py", path="/chainlit")

tests/unit/test_chainlit_api_download.py

@@ -0,0 +1,45 @@
+"""Regression test for the standalone Chainlit app's source-download route.
+
+In Ray Serve mode the API and Chainlit run on separate ports. Source previews
+rewrite their file download links to the browser origin (the Chainlit host),
+so the standalone Chainlit app (``chainlit_api.app``) must expose the
+authorized ``/static/{extract_id}`` download route — otherwise PDFs/images/audio
+from search sources would 404 against the Chainlit service.
+"""
+
+from __future__ import annotations
+
+import importlib
+import sys
+import types
+
+from fastapi import FastAPI
+from fastapi.responses import PlainTextResponse
+
+
+def _import_chainlit_api(monkeypatch):
+    """Import ``chainlit_api`` with ``chainlit`` stubbed out."""
+    chainlit = types.ModuleType("chainlit")
+    chainlit_utils = types.ModuleType("chainlit.utils")
+
+    def mount_chainlit(app: FastAPI, target: str, path: str):
+        @app.get(f"{path}/")
+        async def chainlit_page():
+            return PlainTextResponse("chainlit")
+
+    chainlit_utils.mount_chainlit = mount_chainlit
+    chainlit.utils = chainlit_utils
+    monkeypatch.setitem(sys.modules, "chainlit", chainlit)
+    monkeypatch.setitem(sys.modules, "chainlit.utils", chainlit_utils)
+
+    sys.modules.pop("chainlit_api", None)
+    return importlib.import_module("chainlit_api")
+
+
+def test_standalone_chainlit_exposes_source_download_route(monkeypatch):
+    monkeypatch.setenv("AUTH_MODE", "token")
+
+    module = _import_chainlit_api(monkeypatch)
+
+    routes = {getattr(r, "name", None): getattr(r, "path", None) for r in module.app.routes}
+    assert routes.get("download_source") == "/static/{extract_id}"