Subscription fee strategy

The subscription fee strategy allows a dapp to implement a recurring payment model.

Two ways to implement subscriptions:

• Automatic activation: Users transfer a set amount of a specified token upon registering. If the transferred amount meets the minimum requirement, their account is created with the subscription active.
• Self-serve activation: Users with existing tokens on another chain can transfer the subscription fee directly.

Benefits of subscriptions:

• Recurring revenue: Provides a predictable income stream to support dapp sustainability.
• Easy setup: Simple implementation offers clear advantages to users.

Getting started

A code example with tests is available here.

To begin, expand the app configuration as shown below.

lib.ft4.core.accounts.strategies.transfer:
  rules:
    - sender_blockchain: x"0000000000000000000000000000000000000000000000000000000000000000"
      sender: "*"
      recipient: "*"
      asset:
        - name: "MyTestAsset"
        min_amount: 100L
      timeout_days: 60
      strategy:
      - "subscription"
lib.ft4.core.accounts.strategies.transfer.subscription:
  asset:
    - name: "MyTestAsset" # issued by current blockchain # OR id: x"C633343E4AA3213EA92158648F11BA8DFF606C6CAC80614CFA5F45E57367F823"
    amount: 10L
  subscription_period_days: 30
  free_operations:
    - some_free_operation

This configuration includes two main settings, strategies.transfer and strategies.transfer.subscription. The example above specifies the following:

1. Transfer strategy: For any sender and recipient on any blockchain, transactions involving the "MyTestAsset" asset with a minimum amount of 100 coins can request a subscription. The timeout period is set to 60 days.
2. Subscription strategy: The subscription price is set at 10 "MyTestAsset" coins for a 30-day period. Users may perform some_free_operation even without an active subscription.

To test the configuration above, refer to the provided tests.