The Authorization System

weppy includes an useful authorization system, based on the one available in web2py. With a few lines of code, weppy will create any required database tables and generate forms for access control in your application.

So, how do you use it? Let's find out with an example:

from weppy import App, DAL
from import Auth
from weppy.sessions import SessionCookieManager

app = App(__name__)
app.config.db.uri = "sqlite://storage.sqlite"

db = DAL(app)
auth = Auth(app, db)

app.common_handlers = [

def account(f, k):
    form = auth(f, k)
    return dict(form=form)

That's it.

Write a template page for the account function, including the returned form, and open in your browser. weppy should redirect you to the login page and show you the related form.

Note: weppy's Auth module requires session handling and a DAL instance activated on your application to work properly.

As you've figured out, the exposed account function will be responsible for your app's authorization flow. With the default settings, the Auth module of weppy exposes the following:

  • http://.../{baseurl}/login
  • http://.../{baseurl}/logout
  • http://.../{baseurl}/register
  • http://.../{baseurl}/verify_email
  • http://.../{baseurl}/retrieve_username
  • http://.../{baseurl}/retrieve_password
  • http://.../{baseurl}/reset_password
  • http://.../{baseurl}/request_reset_password
  • http://.../{baseurl}/change_password
  • http://.../{baseurl}/profile

and it creates all the necessary database tables, from users to groups and memberships.

You can change the routing URL for the authorization function:

def account(f, k):
    # code

and even change the name of the exposed function. However, if you do that, you must tell the Auth module to use it to generate the URLs:

auth = Auth(app, db, base_url='mycontrol')

def mycontrol(f, k):
    form = auth(f, k)
    return dict(form=form)

Disable specific actions

You may want to disable some actions exposed by the authorization module. Let's say you don't want the retrieve_username functionality. To do that, just edit your application configuration:

app.config.auth.actions_disabled = ["retrieve_username"]

Add custom actions

You can also define custom actions to be routed by your application. Let's say you want to route "/account/facebook" on your "/account" exposed function:

def myfbfunction():
    # code

auth.register_action("facebook", myfbfunction)

and that's it.

Access control with "requires"

One of the strengths of the authorization module is that it is simple to introduce access controls to your application. Let's say that you need to allow access to a specific zone to only users who are logged in. With weppy, you can do that with one line of code:

from import requires

@requires(auth.is_logged_in, url('unauthorized_page'))
def myprotected_page():
    #some code

As you probably figured out, the requires helper will determine if the condition in the first parameter passed as and if that is not so, weppy will redirect the client to the URL in the second parameter.

You can also pass a function to be invoked as with the second parameter, for example:

def not_auth():

@requires(lambda: auth.has_membership('administrator'), not_auth)
def admin():
    # code

returns an HTTP 403 error.

Note: when you need to evaluate the condition during the request, you should use a lambda function if the first argument passed to requires is not a callable.

Sometimes you may need to return specific contents on missing authorization. In that case, you can write:

from import service

def not_auth():
    return dict(error="Not authorized")

@requires(auth.is_logged_in, not_auth)
def protected():
    return dict(data="Some data here")

so the client will also receive a JSON object on an authorization error.

– OK, dude. What if I want to protect an entire application module with access control?

You can use the RequireHandler instead of decorating any function of your module:

from weppy import AppModule
from weppy.handlers import RequireHandler

mymodule = AppModule(app, "mymodule", __name__)
mymodule.common_handlers = [RequireHandler(some_condition, otherwise)]

If you go this route, just remember to not add access control to your exposed function, otherwise your user won't be able to login.

Authorization models

New in version 0.4

The Auth module defines five models (and the five related database tables) under default behavior:

  • AuthUser
  • AuthGroup
  • AuthMembership
  • AuthPermission
  • AuthEvent

Now, you can customize the models by creating subclasses, and the thing you'll want to model most often is probably going to be a user. Your base class will be AuthUser and from there you can add your fields, like an avatar. You could define your User model like so:

from weppy.dal import Field
from import AuthUser

class User(AuthUser):
    avatar = Field("upload", uploadfolder="uploads")

    form_profile_rw = {
        "avatar": True

and pass it to the Auth instance:

from import Auth
auth = Auth(app, db, usermodel=User)

As you can see, defining your user model by subclassing AuthUser is essentially the same as subclassing Model, but there are some differences. Firstly, the fields you define will be the additional fields you will want to add to the user table. Secondly, you'll use form_profile_rw and form_registration_rw, instead of the form_rw attribute, to treat the field differently for accesses during user registration and during user edits after registration. The default visibility is set to False for any extra fields you define, so the above example allows the client to upload an avatar for their account only with the profile function, not during the registration.

The default fields included in the AuthUser model are:

  • email
  • password
  • first_name
  • last_name

plus some other columns need by the system and hidden to the users.

If you don't want to have the first_name and last_name fields inside your user model (they are set to be not-null), you can subclass the AuthUserBasic model instead, available under, which doesn't include them.

Before seeing how to customize the remaining auth models, let's see which relations are available as default.

Auth relations

The default Auth configuration gives you the ability to use these has_many relations on the AuthUser model (and any model subclassing it):

user = db.AuthUser(id=1)
# referring membership records
# referring group records
# referring permission records
# referring event records

The AuthGroup model has these has_many relations:

group = db.AuthGroup(id=1)
# referring user records
# referring permission records

Consequentially, AuthMembership, AuthPermission and AuthEvent have the inverse belongs_to relations:

membership = db.AuthMembership(id=1)
# referred user record
# referred group record

permission = db.AuthPermission(id=1)
# referred group record

event = db.AuthEvent(id=1)
# referred user record

Customizing auth models

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Users management

Thanks to the models and relations defined by the Auth module, you can manage the users in your application easily. Let's say you want to add a group of administrators:

admins = auth.add_group('administrators')

then you can add users to the administrators' group easily:

admin = db.User(id=42)
# 1st way:
auth.add_membership(admins, admin)
# 2nd way:
auth.add_membership('administrators', admin)
# 3rd way:
# 4th way:

Once you have added groups and memberships, you can use the has_membership helper of the Auth model that we saw previously, in the requires paragraph:

# on the logged user:
# specifying a user:
auth.has_membership('administrator', user)

and you can obviously get all the groups a user is a member of by using relation:


Nonetheless, weppy's Auth module also have a finer management for users, considering permissions:

auth.add_permission(admins, 'ban_users')

As you saw in the example, this allows you to bind specific permissions to groups, and then checks for them both on groups and users:

# on the logged user:
# on specific user:
auth.has_permission('ban_users', user=admin)
# on specific group:
auth.has_permission('ban_users', group=admins)

weppy's Auth permissions also support more details, like a model name and a record:

maintenance = db.Preference(name='maintenance').first()
auth.add_permission(admins, 'write', 'Setting',
# then you will check
auth.has_permission('write', 'Setting',

Blocking users

New in version 0.6

Sometimes you need to lock user operations on your application. The auth module has 2 different locking statuses for this:

  • disabled: the user won't be able to perform the normal auth operation until a reset of their password
  • blocked: the user won't be able to perform any auth operation (they are banned)

You can change an user status in two different ways. The first is directly with your Auth instance:


where the only accepted parameters are an user row (including the id) or just the id of the user involved.

You can also change the user status directly on a user you've selected from the database:

user = User.first()

The allow methods will simply reset any blocking status on the users.

Auth module configuration

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Additional login methods

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