plain.auth 0.19.0

Add users to your app and decide what they can access.

plain.auth

Add users to your app and decide what they can access.

• Overview
• Authentication setup
  • Settings configuration
  • Creating a user model
  • Login views
• Checking if a user is logged in
• Restricting views
• Installation

Overview

The plain.auth package provides user authentication and authorization for Plain applications. Here's a basic example of checking if a user is logged in:

# In a view
if request.user:
    print(f"Hello, {request.user.email}!")
else:
    print("You are not logged in.")

And restricting a view to logged-in users:

from plain.auth.views import AuthViewMixin
from plain.views import View

class ProfileView(AuthViewMixin, View):
    login_required = True

    def get(self):
        return f"Welcome, {self.request.user.email}!"

Authentication setup

Settings configuration

Configure your authentication settings in app/settings.py:

INSTALLED_PACKAGES = [
    # ...
    "plain.auth",
    "plain.sessions",
    "plain.passwords",  # Or another auth method
]

MIDDLEWARE = [
    "plain.sessions.middleware.SessionMiddleware",
    "plain.auth.middleware.AuthenticationMiddleware",
]

AUTH_USER_MODEL = "users.User"
AUTH_LOGIN_URL = "login"

Creating a user model

Create your own user model using plain create users or manually:

# app/users/models.py
from plain import models
from plain.passwords.models import PasswordField


class User(models.Model):
    email = models.EmailField()
    password = PasswordField()
    is_admin = models.BooleanField(default=False)
    created_at = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return self.email

Login views

To log users in, you'll need to pair this package with an authentication method:

• plain-passwords - Username/password authentication
• plain-oauth - OAuth provider authentication
• plain-passkeys (TBD) - WebAuthn/passkey authentication
• plain-passlinks (TBD) - Magic link authentication

Example with password authentication:

# app/urls.py
from plain.auth.views import LogoutView
from plain.urls import path
from plain.passwords.views import PasswordLoginView


class LoginView(PasswordLoginView):
    template_name = "login.html"


urlpatterns = [
    path("logout/", LogoutView, name="logout"),
    path("login/", LoginView, name="login"),
]

Checking if a user is logged in

A request.user will either be None or point to an instance of your AUTH_USER_MODEL.

In templates:

{% if request.user %}
    <p>Hello, {{ request.user.email }}!</p>
{% else %}
    <p>You are not logged in.</p>
{% endif %}

In Python code:

if request.user:
    print(f"Hello, {request.user.email}!")
else:
    print("You are not logged in.")

Restricting views

Use the AuthViewMixin to restrict views to logged-in users, admin users, or custom logic:

from plain.auth.views import AuthViewMixin
from plain.exceptions import PermissionDenied
from plain.views import View


class LoggedInView(AuthViewMixin, View):
    login_required = True


class AdminOnlyView(AuthViewMixin, View):
    login_required = True
    admin_required = True


class CustomPermissionView(AuthViewMixin, View):
    def check_auth(self):
        super().check_auth()
        if not self.request.user.is_special:
            raise PermissionDenied("You're not special!")

The AuthViewMixin provides:

• login_required - Requires a logged-in user
• admin_required - Requires user.is_admin to be True
• check_auth() - Override for custom authorization logic

Installation

Install the plain.auth package from PyPI:

uv add plain.auth