Integrate Django flash messages into Inertia page props

inertia/http.py

@@ -4,6 +4,7 @@
 from json import dumps as json_encode
 from typing import Any, Callable
 
+from django.contrib.messages import get_messages
 from django.core.exceptions import ImproperlyConfigured
 from django.http import HttpRequest, HttpResponse
 from django.template.loader import render_to_string
@@ -112,7 +113,16 @@ def build_props(self) -> Any:
                 if isinstance(_props[key], IgnoreOnFirstLoadProp):
                     del _props[key]
 
-        return deep_transform_callables(_props)
+        _props = deep_transform_callables(_props)
+
+        flash = [
+            {"level": m.level_tag, "message": str(m)}
+            for m in get_messages(self.request)
+        ]
+        if flash:
+            _props["messages"] = flash
+
+        return _props
 
     def build_deferred_props(self) -> dict[str, Any] | None:
         if self.request.is_a_partial_render(self.component):

inertia/tests/test_messages.py

@@ -0,0 +1,24 @@
+from inertia.test import InertiaTestCase
+
+
+class FlashMessagesTestCase(InertiaTestCase):
+    def test_success_message_included_in_props(self):
+        self.inertia.get("/messages/")
+        self.assertIncludesProps({
+            "messages": [{"level": "success", "message": "Profile saved!"}]
+        })
+
+    def test_no_messages_key_when_no_messages(self):
+        self.inertia.get("/no-messages/")
+        self.assertNotIn("messages", self.props())
+
+    def test_messages_consumed_after_render(self):
+        # First request — message should be present
+        self.inertia.get("/messages/")
+        self.assertIncludesProps({
+            "messages": [{"level": "success", "message": "Profile saved!"}]
+        })
+
+        # Second request to a view with no messages — should not carry over
+        self.inertia.get("/no-messages/")
+        self.assertNotIn("messages", self.props())

inertia/tests/testapp/urls.py

@@ -23,4 +23,6 @@
     path("clear-history/", views.clear_history_test),
     path("clear-history-redirect/", views.clear_history_redirect_test),
     path("clear-history-type-error/", views.clear_history_type_error_test),
+    path("messages/", views.messages_test),
+    path("no-messages/", views.no_messages_test),
 ]

inertia/tests/testapp/views.py

@@ -1,3 +1,4 @@
+from django.contrib import messages
 from django.http.response import HttpResponse
 from django.shortcuts import redirect
 from django.utils.decorators import decorator_from_middleware
@@ -152,3 +153,14 @@ def clear_history_redirect_test(request):
 def clear_history_type_error_test(request):
     request.session[INERTIA_SESSION_CLEAR_HISTORY] = "foo"
     return {}
+
+
+@inertia("TestComponent")
+def messages_test(request):
+    messages.success(request, "Profile saved!")
+    return {}
+
+
+@inertia("TestComponent")
+def no_messages_test(request):
+    return {}