[BUG] Django Ninja docs fails when django.contrib.auth is not in INSTALLED_APPS

[devjerry0]

Describe the bug
When trying to access the Django Ninja auto-generated docs at /api/v1/docs, an error occurs if django.contrib.auth is not in INSTALLED_APPS:

This is problematic for projects that intentionally avoid using Django's auth system:

1. It forces including django.contrib.auth in INSTALLED_APPS even when not using Django's auth system
2. This adds unwanted database tables or requires workarounds
3. The only current alternative is to disable docs completely with docs_url=None or create a custom view.

Expected Behavior

Django Ninja's documentation should work without requiring django.contrib.auth to be in INSTALLED_APPS. Ideally:

1. Not depend on Django's auth system for docs rendering
2. Provide a parameter/flag to disable auth or alternative docs viewer that doesn't require auth

Steps to Reproduce

Setup

# settings.py
INSTALLED_APPS = [
    # "django.contrib.auth",  # Not included
    "django.contrib.contenttypes",
    "django.contrib.sessions",
    "django.contrib.messages",
    "django.contrib.staticfiles",
    # Your other apps...
]

# api.py
from ninja import NinjaAPI

api = NinjaAPI(
    title="My API",
    version="1.0.0",
    # Using default docs settings
)

@api.get("/hello")
def hello(request):
    return {"message": "Hello world"}

# urls.py
from django.urls import path
from .api import api

urlpatterns = [
    path("api", api.urls),
]`

You can quickly get this by runninng in ./manage.py shell this line:
import django; import pydantic; import ninja; django.__version__; ninja.__version__; pydantic.__version__

Versions (please complete the following information):

• Python version: 3.12+
• Django version: 5.1+
• Django-Ninja version: 1.3+
• Pydantic version: latest

[vitalik]

Hi @devjerry0 would be nice if you provide a traceback,

I assume you have something like this:

...
  File "/private/tmp/dislip_contradictiveness/.venv/lib/python3.12/site-packages/django/template/context.py", line 259, in bind_template
    context = processor(self.request)
              ^^^^^^^^^^^^^^^^^^^^^^^
  File "/private/tmp/dislip_contradictiveness/.venv/lib/python3.12/site-packages/django/contrib/auth/context_processors.py", line 60, in auth
    from django.contrib.auth.models import AnonymousUser
  File "/private/tmp/dislip_contradictiveness/.venv/lib/python3.12/site-packages/django/contrib/auth/models.py", line 39, in <module>
    class Permission(models.Model):
  File "/private/tmp/dislip_contradictiveness/.venv/lib/python3.12/site-packages/django/db/models/base.py", line 136, in __new__
    raise RuntimeError(
RuntimeError: Model class django.contrib.auth.models.Permission doesn't declare an explicit app_label and isn't in an application in INSTALLED_APPS.

if so you need to remove auth context processor from TEMPLATE settings:

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.request',
                # 'django.contrib.auth.context_processors.auth',   # <-------------- !!!!!!!!!!!!!!!!
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

[devjerry0]

@vitalik thanks for the quick response!
jeez of course I forgot the template config, we don't use templates apart from the openapi docs.

Thank you, worked!
Want me to create a pr on the ninja docs ?

btw my workaround was creating a hacky custom view ^^

import json

from typing import TYPE_CHECKING, Any

from django.http import HttpRequest, HttpResponse
from ninja import NinjaAPI
from ninja.openapi.docs import Swagger

if TYPE_CHECKING:
    from ninja import NinjaAPI

CSRF_TEMPLATE = """{% if add_csrf %}
        configObject.requestInterceptor = (req) => {
            req.headers['X-CSRFToken'] = "{{csrf_token}}";
            return req;
        };
    {% endif %}"""


class CustomDocsViewer(Swagger):
    """Custom documentation viewer that bypasses Django auth.

    This viewer extends the default Swagger viewer but removes the authentication
    requirement by bypassing Django's auth system and CSRF protection.
    """

    def render_page(self, request: HttpRequest, api: "NinjaAPI", **kwargs: Any) -> HttpResponse:
        """Render the API documentation without using Django auth."""
        self.settings["url"] = self.get_openapi_url(api, kwargs)

        with open(self.template_cdn) as f:
            html = (
                f.read()
                .replace("{{ api.title }}", getattr(api, "title", "API Documentation"))
                .replace("{{ swagger_settings | safe }}", json.dumps(self.settings, indent=1))
                .replace(CSRF_TEMPLATE, "")
            )

        return HttpResponse(html)