feat: implement process-local internal authentication for Gateway and enhance CSRF handling

backend/app/gateway/app.py

@@ -79,6 +79,11 @@ async def _ensure_admin_user(app: FastAPI) -> None:
         # Skip admin migration work rather than failing gateway startup.
         logger.warning("Auth persistence not ready; skipping admin bootstrap check")
         return
+
+    sf = get_session_factory()
+    if sf is None:
+        return
+
     admin_count = await provider.count_admin_users()
 
     if admin_count == 0:
@@ -90,10 +95,6 @@ async def _ensure_admin_user(app: FastAPI) -> None:
 
     # Admin already exists — run orphan thread migration for any
     # LangGraph thread metadata that pre-dates the auth module.
-    sf = get_session_factory()
-    if sf is None:
-        return
-
     async with sf() as session:
         stmt = select(UserRow).where(UserRow.system_role == "admin").limit(1)
         row = (await session.execute(stmt)).scalar_one_or_none()

backend/app/gateway/auth_middleware.py

@@ -18,6 +18,7 @@ from starlette.types import ASGIApp
 
 from app.gateway.auth.errors import AuthErrorCode, AuthErrorResponse
 from app.gateway.authz import _ALL_PERMISSIONS, AuthContext
+from app.gateway.internal_auth import INTERNAL_AUTH_HEADER_NAME, get_internal_user, is_valid_internal_auth_token
 from deerflow.runtime.user_context import reset_current_user, set_current_user
 
 # Paths that never require authentication.
@@ -75,8 +76,12 @@ class AuthMiddleware(BaseHTTPMiddleware):
         if _is_public(request.url.path):
             return await call_next(request)
 
+        internal_user = None
+        if is_valid_internal_auth_token(request.headers.get(INTERNAL_AUTH_HEADER_NAME)):
+            internal_user = get_internal_user()
+
         # Non-public path: require session cookie
-        if not request.cookies.get("access_token"):
+        if internal_user is None and not request.cookies.get("access_token"):
             return JSONResponse(
                 status_code=401,
                 content={
@@ -100,10 +105,13 @@ class AuthMiddleware(BaseHTTPMiddleware):
         # bubble up, so we catch and render it as JSONResponse here.
         from app.gateway.deps import get_current_user_from_request
 
-        try:
-            user = await get_current_user_from_request(request)
-        except HTTPException as exc:
-            return JSONResponse(status_code=exc.status_code, content={"detail": exc.detail})
+        if internal_user is not None:
+            user = internal_user
+        else:
+            try:
+                user = await get_current_user_from_request(request)
+            except HTTPException as exc:
+                return JSONResponse(status_code=exc.status_code, content={"detail": exc.detail})
 
         # Stamp both request.state.user (for the contextvar pattern)
         # and request.state.auth (so @require_permission's "auth is

backend/app/gateway/internal_auth.py

@@ -0,0 +1,26 @@
+"""Process-local authentication for Gateway internal callers."""
+
+from __future__ import annotations
+
+import secrets
+from types import SimpleNamespace
+
+from deerflow.runtime.user_context import DEFAULT_USER_ID
+
+INTERNAL_AUTH_HEADER_NAME = "X-DeerFlow-Internal-Token"
+_INTERNAL_AUTH_TOKEN = secrets.token_urlsafe(32)
+
+
+def create_internal_auth_headers() -> dict[str, str]:
+    """Return headers that authenticate same-process Gateway internal calls."""
+    return {INTERNAL_AUTH_HEADER_NAME: _INTERNAL_AUTH_TOKEN}
+
+
+def is_valid_internal_auth_token(token: str | None) -> bool:
+    """Return True when *token* matches the process-local internal token."""
+    return bool(token) and secrets.compare_digest(token, _INTERNAL_AUTH_TOKEN)
+
+
+def get_internal_user():
+    """Return the synthetic user used for trusted internal channel calls."""
+    return SimpleNamespace(id=DEFAULT_USER_ID, system_role="internal")