Django ASGI: send_default_pii triggers request.user.is_authenticated sync access

[ohnoah]

Summary

When running Django under ASGI with send_default_pii=True, Sentry’s Django integration calls request.user.is_authenticated in the ASGI event processor. On Django 5.x this triggers lazy session-backed user resolution in an async context and raises SynchronousOnlyOperation: You cannot call this from an async context.

This appears to happen when the request uses Django’s session auth (e.g. Django admin). It does not occur when user objects are already concretely loaded (custom auth middleware). Disabling send_default_pii avoids the error.

Environment

• Python: 3.11
• Django: 5.1.2
• sentry-sdk: 2.48.0
• Deployment: ASGI (gunicorn + uvicorn worker)

Steps to Reproduce

1. Configure Django with AuthenticationMiddleware + SessionMiddleware.
2. Run under ASGI.
3. Configure Sentry with send_default_pii=True.
4. Hit /admin/ (or any endpoint using Django session auth).

Actual Behavior

Sentry logs an internal SDK error:

.../django/utils/functional.py in _setup
.../sentry_sdk/integrations/django/__init__.py in is_authenticated
return request_user.is_authenticated
.../sentry_sdk/integrations/django/__init__.py in _set_user_info
if user is None or not is_authenticated(user):
.../sentry_sdk/integrations/django/asgi.py in asgi_request_event_processor
_set_user_info(request, event)
.../django/contrib/sessions/backends/base.py in _get_session
return self._session_cache
SynchronousOnlyOperation: You cannot call this from an async context - use a thread or sync_to_async.

Expected Behavior

In async contexts, the Django integration should avoid touching request.user synchronously. Ideally it should use async-safe APIs (e.g. request.auser() / auth.aget_user) or skip user capture in ASGI when send_default_pii is enabled.

Notes

• This appears limited to async requests; WSGI does not raise.
• A workaround is send_default_pii=False and manually calling sentry_sdk.set_user() after resolving the user asynchronously.

[linear]

PY-2023