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.

blockchains:
  <my_blockchain_name>:
    module: <my_module_name>
    moduleArgs:
      lib.ft4.core.admin:
        admin_pubkey: "030F1B600A04BE704499CA4EDCEDD767FC16035522AB40AEB700D391412CD721EA"
      lib.ft4.core.accounts.strategies.transfer.subscription:
        asset:
          - name: "MyTestAsset" # issued by current blockchain
            amount: 10L
        subscription_period_days: 30
        free_operations:
          - some_free_operation
        subscription_account: x"66A117242F7CF1B1E6B830232FD1CA059A6E5111CEE99C8FDC2AFF8CE11BDDE4"
      lib.ft4.core.accounts.strategies.transfer:
        rules:
          - sender_blockchain: "*"
            sender: "*"
            recipient: "*"
            asset:
              - name: "MyTestAsset"
                min_amount: 100L
            timeout_days: 60
            strategy:
              - "subscription"
compile:
  rellVersion: 0.13.14
database:
  schema: schema_my_rell_dapp
test:
  modules:
    - test
  moduleArgs:
    lib.ft4.core.admin:
      admin_pubkey: "030F1B600A04BE704499CA4EDCEDD767FC16035522AB40AEB700D391412CD721EA"
    lib.ft4.core.accounts.strategies.transfer.subscription:
      asset:
        - name: "MyTestAsset" # issued by current blockchain
          amount: 10L
      subscription_period_days: 30
      free_operations:
        - some_free_operation
      subscription_account: x"66A117242F7CF1B1E6B830232FD1CA059A6E5111CEE99C8FDC2AFF8CE11BDDE4"
    lib.ft4.core.accounts.strategies.transfer:
      rules:
        - sender_blockchain: "*"
          sender: "*"
          recipient: "*"
          asset:
            - name: "MyTestAsset"
              min_amount: 100L
          timeout_days: 60
          strategy:
            - "subscription"
libs:
  ft4:
    registry: https://gitlab.com/chromaway/ft4-lib.git
    path: rell/src/lib/ft4
    tagOrBranch: v1.1.0r
    rid: x"FEEB0633698E7650D29DCCFE2996AD57CDC70AA3BDF770365C3D442D9DFC2A5E"
    insecure: false
  iccf:
    registry: https://gitlab.com/chromaway/core/directory-chain
    path: src/iccf
    tagOrBranch: 1.32.2
    rid: x"1D567580C717B91D2F188A4D786DB1D41501086B155A68303661D25364314A4D"
    insecure: false

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.