Token module

The token module handles all logic related to balance. Specifically the following criteria:

  • Validating and subtracting fees for all transactions.

  • Checking the minimum remaining balance requirement.

  • Giving block rewards to the block generator.

  • Transferring account balances.

Name

token

ID

2

Assets
ID Name

0

TransferAsset

Reducers

Actions

none

Events

none

Account schema

The token module adds a new property balance under the key token to every account in the network as follows:

{
    type: 'object',
    properties: {
        balance: {
            fieldNumber: 1,
            dataType: 'uint64',
        },
    },
    default: {
        balance: BigInt(0),
    },
}

Transactions

The following transaction assets are provided by the token module.

TransferAsset

Allows the possibility to execute a transfer transaction, which transfers tokens from one account to another.

Schema
{
    $id: 'lisk/transfer-asset',
    title: 'Transfer transaction asset',
    type: 'object',
    required: ['amount', 'recipientAddress', 'data'],
    properties: {
        amount: {
            dataType: 'uint64',
            fieldNumber: 1,
        },
        recipientAddress: {
            dataType: 'bytes',
            fieldNumber: 2,
            minLength: 20,
            maxLength: 20,
        },
        data: {
            dataType: 'string',
            fieldNumber: 3,
            minLength: 0,
            maxLength: 64,
        },
    },
}

Reducers

credit()

Credits a specific amount of tokens to an account.

credit()
async (params: Record<string, unknown>, stateStore: StateStore): Promise<void> => {
    const { address, amount } = params;
    if (!Buffer.isBuffer(address)) {
        throw new Error('Address must be a buffer');
    }
    if (typeof amount !== 'bigint') {
        throw new Error('Amount must be a bigint');
    }
    if (amount <= BigInt(0)) {
        throw new Error('Amount must be a positive bigint.');
    }
    const account = await stateStore.account.getOrDefault<TokenAccount>(address);
    account.token.balance += amount;
    if (account.token.balance < this._minRemainingBalance) {
        throw new Error(
            `Remaining balance must be greater than ${this._minRemainingBalance.toString()}`,
        );
    }
    await stateStore.account.set(address, account);
},

debit()

Debits a specific amount of tokens from an account.

debit()
async (params: Record<string, unknown>, stateStore: StateStore): Promise<void> => {
    const { address, amount } = params;
    if (!Buffer.isBuffer(address)) {
        throw new Error('Address must be a buffer');
    }
    if (typeof amount !== 'bigint') {
        throw new Error('Amount must be a bigint');
    }
    if (amount <= BigInt(0)) {
        throw new Error('Amount must be a positive bigint.');
    }
    const account = await stateStore.account.getOrDefault<TokenAccount>(address);
    account.token.balance -= amount;
    if (account.token.balance < this._minRemainingBalance) {
        throw new Error(
            `Remaining balance must be greater than ${this._minRemainingBalance.toString()}`,
        );
    }
    await stateStore.account.set(address, account);
},

getBalance()

Get the balance of an specific account.

getBalance()
async (
    params: Record<string, unknown>,
    stateStore: StateStore,
): Promise<bigint> => {
    const { address } = params;
    if (!Buffer.isBuffer(address)) {
        throw new Error('Address must be a buffer');
    }
    const account = await stateStore.account.getOrDefault<TokenAccount>(address);
    return account.token.balance;
},

getMinRemainingBalance()

Returns the minimum remaining balance for accounts.

getMinRemainingBalance()
async (): Promise<bigint> => this._minRemainingBalance,