The Subscription Cycle

The Subscription model (see models) is the corner stone on which access to the service is authorized. It is also a fundamental block of the Flexible Security Framework.

class saas.models.Subscription(*args, **kwargs)

Subscription represent a service contract (Plan) between two Organization, a subscriber and a provider, that is paid by the subscriber to the provider over the lifetime of the subscription.

When auto_renew is True, extend_subscriptions (usually called from a cron job) will invoice the organization for an additional period once the date reaches currenct end of subscription.

Implementation Note: Even through (organization, plan) should be unique at any point in time, it is a little much to implement with PostgreSQL that for each (organization, plan), there should not be overlapping timeframe [created_at, ends_at[.

The djaodjin-saas logic supports subscribe and unsubscribe to multiple plans at any one time but, by default, will generate credit card charges on a billing cycle. At the time a customer first subscribes to a Plan, a billing cycle is established for the Organization. From that time on, a customer is billed at the begining of each billing cycle for all services subscribed to.


Thus all subscriptions are charged as a single credit card charge through the payment processor (see backends available).

In normal business operations, service is available as soon as customer subscribes; service becomes unavailable at the end of a billing cycle.

Whenever potential fraud is detected, that is a customer’s card is denied N number of times or a chargeback is created, a customer is locked out immediately.


Plans can be configured to create one-time-only subcriptions, repeat subscriptions or auto-renewal subscriptions.

Plan.renewal_type Description Example
ONE_TIME The provider wishes to upgrade subscriber to a different plan when the period ends. A 30-day trial plan
REPEAT The service is provided on request. It requires the customer to explicitely take action in the product. Car rental with pre-negotiatied rates
AUTO_RENEW The service is provided continuoulsly until canceled. web hosting

When a Subscription for a Plan where renewal_type == AUTO_RENEW is created, Subscription.auto_renew is set to True to tell the periodic renewal task to automatically extends the subscription for one more period in the day before it ends.

The function saas.renewals.extend_subscriptions(at_time) iterates through all active subscription that ends in a day of at_time and which have auto_renew == True, and records a subscription order in the Transaction ledger for each of them.

Later, saas.renewals.create_charges_for_balance calls the processor backend to create an actual charge for the balance due by an Organization.

When a subscription is canceled, auto_renew is set to False. ends_at is set to the current date/time (cancel now) or left unchanged (cancel at end of period).

Expiration notices

Expiration notices (if any) are triggered 90, 60, 30, 15 and 1 day(s) before a subscription ends. This can be changed through the EXPIRE_NOTICE_DAYS in

SAAS = {
    "EXPIRE_NOTICE_DAYS": [90, 60, 30, 15, 1]

Different types of expiration notices are sent based on the value of Plan.renewal_type, Subscription.auto_renew, and the subscriber payment method.

A subscriber payment method (i.e. Organization) can be either be absent, valid or expired. The payment method status is determined at the time a renewal Charge would be created.

There would be 18 (3 * 2 * 3) combinations of expiration notices if a few combinations could not happen.

  • Subscription.auto_renew shall be false when Plan.renewal_type is

ONE_TIME because it does not make sense to have a subscription that renews if the plan states the subscription length is fixed to one period.

  • Subscription.auto_renew shall also be set to false when Plan.renewal_type is REPEAT. Without adding this constraint, there is no direct means to detect subscriptions to a repeat plan that would be “canceled”.

We assume here that cancelation of repeat plans is uninteresting (if either possible) and state that cancelation only makes sense with plans having an auto-renew behavior. Thus, instead of adding another state variable, we use Plan.renewal == AUTO_RENEW && Subscription.auto_renew == false to detect cancelations of auto-renewals.

The signals triggered by saas.renewals.trigger_expiration_notices are such for the available combinations

Plan Subscription Organization payment method ACTION
ONE_TIME auto_renew=false ABSENT Upgrades notice
ONE_TIME auto_renew=false VALID Upgrades notice
ONE_TIME auto_renew=false EXPIRED Upgrades notice
REPEAT auto_renew=false ABSENT Expiration notice
REPEAT auto_renew=false VALID Expiration notice
REPEAT auto_renew=false EXPIRED Expiration notice
AUTO_RENEW auto_renew=false ABSENT None (canceled)
AUTO_RENEW auto_renew=false VALID None (canceled)
AUTO_RENEW auto_renew=false EXPIRED None (canceled)
AUTO_RENEW auto_renew=true ABSENT Attach payment method notice
AUTO_RENEW auto_renew=true VALID None
AUTO_RENEW auto_renew=true EXPIRED Payment method will expire notice