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setExternalChainAddress

Function Type: external
Function Signature: setExternalChainAddress(bytes32,string)
Access Control: onlyAdmin
Returns: void

Configures the external chain station address for all supported cross-chain protocols. This administrative function establishes the connection between the host chain station and its counterpart on external blockchains.

Parameters​

ParameterTypeDescription
externalChainStationAddressBytes32bytes32External station address in bytes32 format (for Hyperlane and LayerZero)
externalChainStationAddressStringstringExternal station address in string format (for Axelar)

Access Control​

modifier onlyAdmin() {
    if (msg.sender != admin.current) {
        revert();
    }
    _;
}

Only the current admin can call this function.

Workflow​

1. Hyperlane Configuration​

hyperlane.externalChainStationAddress = externalChainStationAddressBytes32;

Sets the external chain station address for Hyperlane protocol communication.

2. LayerZero Configuration​

layerZero.externalChainStationAddress = externalChainStationAddressBytes32;

Sets the external chain station address for LayerZero protocol communication.

3. Axelar Configuration​

axelar.externalChainStationAddress = externalChainStationAddressString;

Sets the external chain station address for Axelar protocol communication using string format.

4. LayerZero Peer Setup​

_setPeer(
    layerZero.externalChainStationEid,
    layerZero.externalChainStationAddress
);

Establishes the peer relationship in LayerZero's OApp framework for secure message passing.

Protocol-Specific Address Formats​

Hyperlane & LayerZero​

  • Format: bytes32
  • Usage: Direct address representation for protocol routing
  • Example: 0x742d35Cc6634C0532925a3b8D43C1C16bE8c91234567... (truncated to 32 bytes)

Axelar​

  • Format: string
  • Usage: Human-readable address for Axelar gateway calls
  • Example: "0x742d35Cc6634C0532925a3b8D43C1C16bE8c91234567"

Configuration Requirements​

Before calling this function, ensure:

  1. External Station Deployment: The external chain station contract is deployed on the target blockchain
  2. Address Verification: Both address formats represent the same deployed contract
  3. Protocol Compatibility: The external station supports all three protocols (Hyperlane, LayerZero, Axelar)

Security Considerations​

Address Validation​

  • Critical Setup: Incorrect addresses will break cross-chain communication
  • No Reversal: Once set, addresses affect all future cross-chain operations
  • Format Consistency: Both bytes32 and string parameters must represent the same contract

Admin Control​

  • Single Point: Only current admin can modify these addresses
  • Time Delay: Admin changes follow 1-day time delay governance (see Admin Functions)

Configuration Dependencies​

This function configures addresses but relies on constructor initialization for:

  • Domain/Chain IDs: Set during contract deployment
  • Protocol Endpoints: Hyperlane mailbox, LayerZero endpoint, Axelar gateway addresses
  • Gas Service: Axelar gas service configuration

Protocol Integration Effects​

Hyperlane​

  • Messages sent to hyperlane.externalChainStationDomainId
  • Delivered to hyperlane.externalChainStationAddress
  • Authenticated by domain and address validation

LayerZero​

  • Messages sent to layerZero.externalChainStationEid
  • Peer relationship established with layerZero.externalChainStationAddress
  • OApp security through trusted peer configuration

Axelar​

  • Contract calls to axelar.externalChainStationChainName
  • Target address axelar.externalChainStationAddress
  • Gateway routing and execution validation

Error Conditions​

ErrorCondition
Access Control RevertCalled by non-admin address
LayerZero Peer ErrorInvalid EID or address format for _setPeer

Usage Example​

// Example configuration call
setExternalChainAddress(
    0x742d35Cc6634C0532925a3b8D43C1C16bE8c9123456789abcdef123456789abcd, // bytes32 format
    "0x742d35Cc6634C0532925a3b8D43C1C16bE8c91234567" // string format
);

Post-Configuration Verification​

After calling this function, verify configuration through getter functions:

  • getHyperlaneConfig(): Confirm Hyperlane address setting
  • getLayerZeroConfig(): Confirm LayerZero address and peer setup
  • getAxelarConfig(): Confirm Axelar address setting
Critical Configuration

This function establishes the foundation for all cross-chain communication. Incorrect addresses will result in failed transfers and potential loss of funds. Always verify external station deployment and address accuracy before configuration.