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Technical Specifications

Dynamic Address Generation​

  • Contract: RouterRelay
    • addressForTokenDeposit: Generates a dynamic, single-use deposit address for token deposits based on user-supplied data, which can also be displayed as a QR code for easy scanning.
    • sendTokenDeposit: Deploys a DepositReceiver contract to handle the asset forwarding and initiate cross-chain transfers.

Asset Transfer and Forwarding​

  • Contract: ReceiverImplementation
  • Purpose: Receives assets and forwards them as per user-specified data. Handles transaction failures with a refund mechanism.
  • Core Components:
    • Data Structure: GenericData
      • callTo: Target address for forward operation (e.g., another contract).
      • approvalTo: Address for granting token approval if required.
      • data: Encoded transaction data for interaction.
      • srcToken: Address of the asset being transferred.
      • refundAddress: Address for refunds in case of transaction failure.
      • Native Asset Identifier: NATIVE_ASSETID to detect and handle native tokens (e.g., ETH).
    • Key Function: receiveAndSendToken
      • Verifies callTo and refundAddress are non-zero.
      • Identifies asset type (native/ERC20) and retrieves the balance.
      • Grants approval for ERC20 transfers if necessary and initiates a call to callTo with data.
      • If the transaction fails, refunds the balance to refundAddress.
      • Uses safeTransfer for ERC20 tokens, ensuring a secure refund process.

Temporary Deposit Receiver Contract​

  • Contract: DepositReceiver
  • Purpose: Acts as a transient address to hold the user’s tokens and call ReceiverImplementation using delegatecall.
  • Core Components:
    • Constructor:
      • Executes delegatecall to ReceiverImplementation for asset handling.
      • If delegatecall fails, reverts with the original error and refunds assets to refundAddress.
      • Self-destructs after transaction completion to clear storage and prevent reuse.
      • Fallback Function: Receives native tokens (e.g., ETH), allowing flexibility for handling WETH and similar assets.

Deterministic Address Calculation​

  • _depositAddress Function in RouterRelay.
  • Uses CREATE2 for predictable address generation based on salt and genericData.
  • Allows the creation of identical addresses across chains, simplifying cross-chain deposits.