# Custom AdminSite clashes with app\_name; throws "NoReverseMatch at /admin/"

**URL:** <https://forum.djangoproject.com/t/custom-adminsite-clashes-with-app-name-throws-noreversematch-at-admin/18380>\
**Category:** Mystery Errors\
**Created:** [January 23, 2023, 7:19pm UTC](https://forum.djangoproject.com/t/custom-adminsite-clashes-with-app-name-throws-noreversematch-at-admin/18380 "2023-01-23T19:19:28Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![PedroPerpetua](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.djangoproject.com/pedroperpetua/32/11895_2.png) [@PedroPerpetua](https://forum.djangoproject.com/u/PedroPerpetua)\
**Post date:** [January 23, 2023, 7:19pm UTC](https://forum.djangoproject.com/t/custom-adminsite-clashes-with-app-name-throws-noreversematch-at-admin/18380/1 "2023-01-23T19:19:28Z")

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Hello everyone - first post. I tried searching about this issue and didn’t find much; was wondering if I’m missing some configurations or if this is perhaps a bug? Though it feels like someone would’ve stumbled upon such a simple thing before but I couldn’t find much.

The TL:DR is that having a custom AdminSite in some app and then included in that app’s urls, if that app also defines an “app\_name” in said urls, Django will throw a NoReverseMatch error when trying to access that admin page.

Now for a detailed explanation, assume the following Django project:

```auto
app/
├── app/
│ ├── settings.py
│ ├── urls.py
│ └── ...
└── my_custom_app/
    ├── admin.py
    ├── urls.py
    └── ...

```

Where the files are, as expected:

```plaintext
# my_custom_app/admin.py
from django.contrib import admin

class AdminSite(admin.AdminSite):
    pass

# my_custom_app/urls.py
from django.urls import path
from core.admin import admin_site

app_name = "my_custom_app" # this is the problematic line

urlpatterns = [
    path("admin/", admin_site.urls, name="admin"),
]

# app/urls.py
from django.conf import settings
from django.urls import include, path

urlpatterns = [
    path("", include("my_custom_app.urls")),
]

```

Note: `my_custom_app` is installed in the settings as the last app

When trying to access `<server_address>/admin`, instead of having access to the Django admin, the server will throw a “NoReverseMatch at /admin/” error, citing “‘admin’ is not a registered namespace”. Now, if you remove the “problematic line” (`app_name = "my_custom_app"` from `my_custom_app/urls.py`), the problem vanishes and everything works as expected.

Aditional details:  
Django version: 4.1.5  
I do have a bunch of other common modules installed, but they shouldn’t have anything to do with the issue I think:

```auto
rest_framework
rest_framework_simplejwt
rest_framework_simplejwt.token_blacklist
drf_standardized_errors
corsheaders

```

Am I doing something wrong?

---

<div class="post-metadata">

**Author:** ![KenWhitesell](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.djangoproject.com/kenwhitesell/32/280_2.png) [@KenWhitesell](https://forum.djangoproject.com/u/KenWhitesell)\
**Post date:** [January 23, 2023, 7:40pm UTC](https://forum.djangoproject.com/t/custom-adminsite-clashes-with-app-name-throws-noreversematch-at-admin/18380/2 "2023-01-23T19:40:51Z")

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Are you looking to use this custom AdminSite in _addition_ to the default site or _instead_ of?

Note, if you are looking to replace the default site, you don’t show your `apps.py` file here.

You may want to review the docs for both [Customizing the `AdminSite` class](https://docs.djangoproject.com/en/4.1/ref/contrib/admin/#customizing-the-adminsite-class) and [Overriding the default admin site](https://docs.djangoproject.com/en/4.1/ref/contrib/admin/#overriding-the-default-admin-site).

But yes, adding the app\_name to your urls.py file creates a namespace for the urls defined within it, which means they would be reversed by using names like “my\_custom\_app:admin” and not just “admin”.

---

<div class="post-metadata">

**Author:** ![PedroPerpetua](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.djangoproject.com/pedroperpetua/32/11895_2.png) [@PedroPerpetua](https://forum.djangoproject.com/u/PedroPerpetua)\
**Post date:** [January 23, 2023, 7:54pm UTC](https://forum.djangoproject.com/t/custom-adminsite-clashes-with-app-name-throws-noreversematch-at-admin/18380/3 "2023-01-23T19:54:25Z")

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> Are you looking to use this custom AdminSite in _addition_ to the default site or _instead_ of?

My intent is to replace the default one (so _instead of_). I keep it in a `core` app alongside some other, well, “core functionality”, including a couple more views. My issue is that indeed, I can’t keep it’s url there alongside the other app urls if I want the other reverse names to be `core:<view_name>`.

> Note, if you are looking to replace the default site, you don’t show your `apps.py` file here.  
> You may want to review the docs for both [Customizing the `AdminSite` class](https://docs.djangoproject.com/en/4.1/ref/contrib/admin/#customizing-the-adminsite-class) and [Overriding the default admin site](https://docs.djangoproject.com/en/4.1/ref/contrib/admin/#overriding-the-default-admin-site).

I’m now reading the part on _Overriding the default admin site_. This is the prefered approach to do this then? Should I be keeping the admin site in some sort of seperate app instead of keeping it bundled with “core”.

The idea behind it being bundled in the “core” app is that I have my other apps with their own `admin.py` file where they import the admin\_site from `core.admin` and then define their own admin classes to register.

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<div class="post-metadata">

**Author:** ![KenWhitesell](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.djangoproject.com/kenwhitesell/32/280_2.png) [@KenWhitesell](https://forum.djangoproject.com/u/KenWhitesell)\
**Post date:** [January 23, 2023, 8:02pm UTC](https://forum.djangoproject.com/t/custom-adminsite-clashes-with-app-name-throws-noreversematch-at-admin/18380/4 "2023-01-23T20:02:37Z")

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Notice in that section on Overriding… that they show the directory as being `myproject` and not `myapp` for those files. I would interpret that as meaning that no - a custom admin site that is replacing the default does _not_ belong in an app, it’s a project-level configuration item.

Your other apps then would import the site from `myproject.admin` and not `core.admin`.

(This is under the working assumption that you’re using the default directory structure that includes a `myproject` directory that is inside the BASE\_DIR `myproject` directory.)

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<div class="post-metadata">

**Author:** ![PedroPerpetua](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.djangoproject.com/pedroperpetua/32/11895_2.png) [@PedroPerpetua](https://forum.djangoproject.com/u/PedroPerpetua)\
**Post date:** [January 23, 2023, 8:09pm UTC](https://forum.djangoproject.com/t/custom-adminsite-clashes-with-app-name-throws-noreversematch-at-admin/18380/5 "2023-01-23T20:09:02Z")

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Thank you! That makes sense. I’ll experiment with it and report back.

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<div class="post-metadata">

**Author:** ![PedroPerpetua](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.djangoproject.com/pedroperpetua/32/11895_2.png) [@PedroPerpetua](https://forum.djangoproject.com/u/PedroPerpetua)\
**Post date:** [January 27, 2023, 11:44pm UTC](https://forum.djangoproject.com/t/custom-adminsite-clashes-with-app-name-throws-noreversematch-at-admin/18380/6 "2023-01-27T23:44:04Z")

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Just to update on this; I didn’t have much time to get the Overriding to work, and just called it that the solution I currently had was good enough. I’ll mark this as solution if someone else comes across and wants to try it.