Authorization

The user should grant authorization to allow smart contracts to send messages on behalf of a user account. This is achieved by the Authorization.sol that provides the necessary functions to grant approvals and allowances. The precompiled contracts use the AuthorizationI interface, to allow users to approve the corresponding messages and amounts.

Solidity Interfaces

Authorization.sol

Find the Solidity interface in the evmos/extensions repo.

Transactions

• approve

  Approves a list of Cosmos or IBC transactions with a specific amount of tokens

  function approve(
          address spender,
          uint256 amount,
          string[] calldata methods
      ) external returns (bool approved);

• revoke

  Revokes authorizations of Cosmos transactions.

  function revoke(
      address spender,
      string[] calldata methods
  ) external returns (bool revoked);

• increaseAllowance

  Increase the allowance of a given spender by a specific amount of tokens for IBC transfer methods or staking

  function increaseAllowance(
          address spender,
          uint256 amount,
          string[] calldata methods
      ) external returns (bool approved);

• decreaseAllowance

  Decreases the allowance of a given spender by a specific amount of tokens for IBC transfer methods or staking

  function decreaseAllowance(
          address spender,
          uint256 amount,
          string[] calldata methods
      ) external returns (bool approved);

Queries

• allowance

  Returns the remaining number of tokens that the spender will be allowed to spend on behalf of the owner through IBC transfer methods or staking. This is zero by default

  function allowance(
          address owner,
          address spender,
          string calldata method
  ) external view returns (uint256 remaining);

Events

• Approval

  This event is emitted when the allowance of a spender is set by a call to the approve method. The value field specifies the new allowance and the methods field holds the information for which methods the approval was set.

  event Approval(
          address indexed owner,
          address indexed spender,
          string[] methods,
          uint256 value
      );

• Revocation

  This event is emitted when an owner revokes a spender's allowance.

  event Revocation(
      address indexed owner,
      address indexed spender,
      string[] methods
  );

• AllowanceChange

  This event is emitted when the allowance of a spender is changed by a call to the decrease or increase allowance method. The values field specifies the new allowances and the methods field holds the information for which methods the approval was set.

  event AllowanceChange(
          address indexed owner,
          address indexed spender,
          string[] methods,
          uint256[] values
      );