Hooks

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  • EVM Hooks
  • Governance Hooks

The erc20 module implements two transaction hooks from the EVM and Governance modules

EVM Hooks

👉 Purpose: Allow for users to convert ERC20s to Cosmos Coins by sending an Ethereum tx transfer to the module account address. This enables native conversion of tokens via Metamask and EVM-enabled wallets.

Registered Coin: ERC20 to Coin

1. User transfers ERC20 tokens to the ModuleAccount address to escrow (lock)
2. Check if the ERC20 Token that was transferred from the sender is a native ERC20 or a native cosmos coin by looking at the ethereum Logs
3. If the token contract address is corresponds to the ERC20 representation of a native Cosmos Coin
   1. Call burn() ERC20 method from the ModuleAccount
      1. NOTE: This is the same as 1.2, but since the tokens are already on the ModuleAccount balance, we burn the tokens from the module address instead of calling burnFrom()
      2. NOTE: We don't need to mint because (1.1) escrows the coin
   2. Transfer Cosmos Coin to the bech32 account address of the sender hex address (1.)

Registered ERC20: ERC20 to Coin

1. User transfers coins to the Module Account to escrow (lock)
2. Check if the ERC20 Token that was transferred is a native ERC20 or a native cosmos coin
3. If the token contract address is a native ERC20 token
   1. Mint Cosmos Coin
   2. Transfer Cosmos Coin to the bech32 account address of the sender hex (1.)

Governance Hooks

👉 Purpose: speed up the approval process of a token pair registration by defining a custom VotingPeriod duration for the RegisterCoinProposal and RegisterERC20Proposal.

Overwriting the Voting Period

By Implementing the GovHooks (opens new window) Interface from the Cosmos-SDK, the voting period for all proposals of the ERC20 module can be customized using the AfterProposalDeposit hook.

1. Set the voting period on the erc20 module parameters at genesis or through governance
2. Submit a new governance proposal, e.g. RegisterERC20Proposal
3. The AfterProposalDeposit hook is automatically called and overrides the voting period for all proposals to the value defined on the erc20 module parameters.