Transfer strategies

FT4 includes three registration strategies that require the user to transfer tokens before an account exists: transfer open, transfer fee, and transfer subscription. Each requires a token transfer to activate the account, but they differ in how, or whether, you earn revenue from it.

Transfer open strategy

With transfer open, the user sends a set amount of tokens to an account that doesn't exist yet, then claims that account to activate it. Think of the non-existent account as an empty account waiting for funds. After activation, the user can spend the tokens that were sent to it.

This option sits between fully free registration and the paid strategies: a token transfer is required, but no fee is charged.

Code example for transfer open strategy

Start from the template using the transfer open examples and their tests.

Add this registration configuration to your chromia.yml file:

lib.ft4.core.accounts.strategies.transfer:  rules:    - sender_blockchain: x"0000000000000000000000000000000000000000000000000000000000000000"    sender: "*"    recipient: "*"    asset:        - name: "MyTestAsset"        min_amount: 100L    timeout_days: 60    strategy:    - "open"

Transfer fee strategy

Transfer fee asks the user to buy a set amount of tokens once to unlock your dapp's features. It suits users who want a single, straightforward step.

To register, the user transfers a set amount of tokens to a non-existent account, which is an empty account that must be topped up. When the tokens arrive, the fee is subtracted from the transferred amount.

Code example for transfer fee strategy

Start from the template using the transfer fee examples and their tests.

Add this configuration to your chromia.yml file:

lib.ft4.core.accounts.strategies.transfer:  rules:    - sender_blockchain: x"0000000000000000000000000000000000000000000000000000000000000000"    sender: "*"    recipient: "*"    asset:        - name: "MyTestAsset"        min_amount: 100L    timeout_days: 60    strategy:    - "fee"lib.ft4.core.accounts.strategies.transfer.fee:  asset:    - name: "MyTestAsset" # issued by current blockchain    amount: 40L  fee_account: x"YOUR_FEE_ACCOUNT_ADDRESS" # All fees will be collected into this account

Transfer subscription strategy

Transfer subscription charges users on a recurring basis to keep using your dapp, giving you a steady income to maintain and develop it.

Setup involves a few steps. You first enable subscriptions in chromia.yml. The user then calls the transfer function, pays a predefined fee, and sends a set amount of tokens to a non-existent account, an empty account that must be funded and is central to the flow.

Next, the user calls the claim function to take ownership of that account. You control the subscription length with subscription_period_days in chromia.yml. Once the period expires, the account becomes inactive and can't be used. The user reactivates it by renewing, which means sending a set amount of tokens to the account.

Code example for transfer subscription strategy

Start from the template using the transfer subscription examples and their tests, which show the full implementation.

To enable subscriptions, paste this configuration into your chromia.yml file:

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

Strategy comparison

Configuration properties