Distribution

Solidity Interface & ABI​

Distribution.sol is an interface through which Solidity contracts can interact with Cosmos SDK distribution. This is convenient for developers as they don’t need to know the implementation details behind the x/distribution module in the Cosmos SDK. Instead, they can interact with distribution functions using the Ethereum interface they are familiar with.

Interface Distribution.sol​

Find the Solidity interface in the evmos/extensions repo.

ABI​

Find the ABI in the evmos/extensions repo.

Transactions​

• setWithdrawAddress

  /// @dev Change the address, that can withdraw the rewards of a delegator.
  /// Note that this address cannot be a module account.
  /// @param delegatorAddress The address of the delegator
  /// @param withdrawerAddress The address that will be capable of withdrawing rewards for
  /// the given delegator address
  function setWithdrawAddress(
      address delegatorAddress,
      string memory withdrawerAddress
  ) external returns (bool success);

• withdrawDelegatorRewards

  /// @dev Withdraw the rewards of a delegator from a validator
  /// @param delegatorAddress The address of the delegator
  /// @param validatorAddress The address of the validator
  /// @return amount The amount of Coin withdrawn
  function withdrawDelegatorRewards(
      address delegatorAddress,
      string memory validatorAddress
  )
  external
  returns (
      Coin[] calldata amount
  );

• withdrawValidatorCommission

  /// @dev Withdraws the rewards commission of a validator.
  /// @param validatorAddress The address of the validator
  /// @return amount The amount of Coin withdrawn
  function withdrawValidatorCommission(
      string memory validatorAddress
  )
  external
  returns (
      Coin[] calldata amount
  );

Queries​

• validatorDistribution

  /// @dev Queries validator commission and self-delegation rewards for validator.
  /// @param validatorAddress The address of the validator
  /// @return distributionInfo The validator's distribution info
  function validatorDistributionInfo(
      string memory validatorAddress
  )
  external
  view
  returns (
      ValidatorDistributionInfo[] calldata distributionInfo
  );

• validatorOutstandingRewards

  /// @dev Queries the outstanding rewards of a validator address.
  /// @param validatorAddress The address of the validator
  /// @return rewards The validator's outstanding rewards
  function validatorOutstandingRewards(
      string memory validatorAddress
  )
  external
  view
  returns (
      DecCoin[] calldata rewards
  );

• validatorCommission

  /// @dev Queries the accumulated commission for a validator.
  /// @param validatorAddress The address of the validator
  /// @return commission The validator's commission
  function validatorCommission(
      string memory validatorAddress
  )
  external
  view
  returns (
      DecCoin[] calldata commission
  );

• validatorSlashes

  /// @dev Queries the slashing events for a validator in a given height interval
  /// defined by the starting and ending height.
  /// @param validatorAddress The address of the validator
  /// @param startingHeight The starting height
  /// @param endingHeight The ending height
  /// @return slashes The validator's slash events
  /// @return pageResponse The pagination response for the query
  function validatorSlashes(
      string memory validatorAddress,
      uint64 startingHeight,
      uint64 endingHeight
  )
  external
  view
  returns (
      ValidatorSlashEvent[] calldata slashes,
      PageResponse calldata pageResponse
  );

• delegationRewards

  /// @dev Queries the total rewards accrued by a delegation from a specific address to a given validator.
  /// @param delegatorAddress The address of the delegator
  /// @param validatorAddress The address of the validator
  /// @return rewards The total rewards accrued by a delegation.
  function delegationRewards(
      address delegatorAddress,
      string memory validatorAddress
  )
  external
  view
  returns (
      DecCoin[] calldata rewards
  );

• delegationTotalRewards

  /// @dev Queries the total rewards accrued by each validator, that a given
  /// address has delegated to.
  /// @param delegatorAddress The address of the delegator
  /// @return rewards The total rewards accrued by each validator for a delegator.
  /// @return total The total rewards accrued by a delegator.
  function delegationTotalRewards(
      address delegatorAddress
  )
  external
  view
  returns (
      DelegationDelegatorReward[] calldata rewards,
      DecCoin[] calldata total
  );

• delegatorValidators

  /// @dev Queries all validators, that a given address has delegated to.
  /// @param delegatorAddress The address of the delegator
  /// @return validators The addresses of all validators, that were delegated to by the given address.
  function delegatorValidators(
      address delegatorAddress
  ) external view returns (string[] calldata validators);

• delegatorWithdrawAddress

  delegatorWithdrawAddress queries withdraw address of a delegator

  /// @dev Queries the address capable of withdrawing rewards for a given delegator.
  /// @param delegatorAddress The address of the delegator
  /// @return withdrawAddress The address capable of withdrawing rewards for the delegator.
  function delegatorWithdrawAddress(
      address delegatorAddress
  ) external view returns (string memory withdrawAddress);

Events​

Each of the transactions emits its corresponding event. These are:

• SetWithdrawerAddress

  /// @dev SetWithdrawerAddress defines an Event emitted when a new withdrawer address is being set
  /// @param caller the caller of the transaction
  /// @param withdrawerAddress the newly set withdrawer address
  event SetWithdrawerAddress(
      address indexed caller,
      string withdrawerAddress
  );

• WithdrawDelegatorRewards

  /// @dev WithdrawDelegatorRewards defines an Event emitted when rewards from a delegation are withdrawn
  /// @param delegatorAddress the address of the delegator
  /// @param validatorAddress the address of the validator
  /// @param amount the amount being withdrawn from the delegation
  event WithdrawDelegatorRewards(
      address indexed delegatorAddress,
      string indexed validatorAddress,
      uint256 amount
  );

• WithdrawValidatorCommission

  /// @dev WithdrawValidatorCommission defines an Event emitted when validator commissions are being withdrawn
  /// @param validatorAddress is the address of the validator
  /// @param commission is the total commission earned by the validator
  event WithdrawValidatorCommission(
      string indexed validatorAddress,
      uint256 commission
  );

Interact with the Solidity Interface​

Below are some examples of how to interact with this Solidity interface from your smart contracts.

Make sure to import the precompiled interface, e.g.:

import "https://github.com/financiyo/extensions/blob/main/precompiles/stateful/Distribution.sol";

Grant approval for the desired messages​

See below a function that grants approval to the smart contract to send all x/distribution module messages on behalf of the sender account. You can tweak this function to approve only the desired messages.

string[] private distributionMethods = [
    MSG_SET_WITHDRAWER_ADDRESS,
    MSG_WITHDRAW_DELEGATOR_REWARD,
    MSG_WITHDRAW_VALIDATOR_COMMISSION,
];

/// @dev Approves all distribution transactions.
/// @dev This creates a Cosmos Authorization Grant for the given methods.
/// @dev This emits an Approval event from the GenericAuthorization.sol.
function approveAllDistributionMethods() public {
    bool success = DISTRIBUTION_CONTRACT.approve(
        msg.sender,
        distributionMethods
    );
    require(success, "Failed to approve distribution methods");
}

Set withdraw address​

The changeWithdrawAddress function allows a user to set a new withdraw address in the Cosmos x/distribution module. For this transaction to be successful, make sure the user had already approved the MSG_SET_WITHDRAWER_ADDRESS message.

function changeWithdrawAddress(
    string memory _withdrawAddr
) public returns (bool) {
    return
        distribution.DISTRIBUTION_CONTRACT.setWithdrawAddress(
            msg.sender,
            _withdrawAddr
        );
}

Withdraw staking rewards​

The withdrawStakingRewards function allows a user to withdraw his/her rewards corresponding to a specified validator. For this transaction to be successful, make sure the user had already approved the MSG_WITHDRAW_DELEGATOR_REWARD message.

    function withdrawStakingRewards(
    string memory _valAddr
) public returns (types.Coin[] memory) {
    return
        distribution.DISTRIBUTION_CONTRACT.withdrawDelegatorRewards(
            msg.sender,
            _valAddr
        );
}

Withdraw validator commission​

If the user is running a validator, he/she could withdraw the corresponding commission using a smart contract. The user could use a function similar to withdrawCommission. For this transaction to be successful, make sure the user had already approved the MSG_WITHDRAW_VALIDATOR_COMMISSION message.

function withdrawCommission(
    string memory _valAddr
) public returns (types.Coin[] memory) {
    return
        distribution.DISTRIBUTION_CONTRACT.withdrawValidatorCommission(
            _valAddr
        );
}

Queries​

Similarly to transactions, smart contracts can use query methods. To use these methods, there is no need for authorization, as these are read-only methods. Examples of this are the getDelegationRewards and getValidatorCommision functions that return the information for the specified validator address.

getDelegationRewards(
    string memory _valAddr
) public view returns (types.DecCoin[] memory) {
    return
        distribution.DISTRIBUTION_CONTRACT.delegationRewards(
            msg.sender,
            _valAddr
        );
}

function getValidatorCommission(
    string memory _valAddr
) public view returns (types.DecCoin[] memory) {
    return distribution.DISTRIBUTION_CONTRACT.validatorCommission(_valAddr);
}