Bridge Mechanisms

Curvance implements a cross-chain bridging system for CVE tokens, allowing seamless movement between all supported blockchains through the Protocol Messaging Hub. This guide explains how the bridge. The bridging process leverages established bridge providers with these key components:

• Native Bridge Integration: Utilizes secure, audited bridges like Wormhole or other similar infrastructure.

• Gas Management: Native gas tokens are stored in the Protocol Messaging Hub to pay for cross-chain actions.

• Message Verification: Ensures secure cross-chain message delivery with proper verification mechanisms.

• Consistent Supply Management: Maintains proper token supply accounting across all chains through burn/mint or lock/release patterns.

Architectural Design

The CVE bridge architecture follows a burn-and-mint pattern:

1. Source Chain: CVE tokens are burned (removed from circulation)

2. Message Relay: Cross-chain message is sent via the underlying bridge provider

3. Destination Chain: Equivalent CVE tokens are minted to the recipient

Core Bridging Functions

bridge()

Burns the specified amount of CVE tokens from the caller's balance on the source chain and initiates a cross-chain message through the Protocol Messaging Hub. The message instructs the destination chain to mint an equivalent amount of tokens to the recipient. The function requires a fee payment in native tokens (attached via msg.value) to cover cross-chain messaging costs. The caller must have sufficient CVE balance. Emits a BridgeTokens event upon successful initiation.

Function Signature:

function bridge(
    address recipient,
    uint256 dstChainId, 
    uint256 amount, 
    uint256 gasLimit) 
    external payable;

Parameter	Type	Description
recipient	address	The address that will receive tokens on the destination chain
dstChainId	uint256	The address that will receive tokens on the destination chain
amount	uint256	Amount of CVE tokens to bridge (in wei)
gasLimit	uint256	Gas limit for execution on the destination chain

bridgeFee()

Returns the estimated amount of native tokens required to pay for the cross-chain bridge operation. The fee varies based on the destination chain, current network conditions, and the specified gas limit. This is a view function that doesn't modify state. The returned fee should be sent along with the bridge function call. Fees typically cover bridge provider costs, destination chain gas fees, and relayer compensation. Higher gas limits increase the fee but provide more execution resources on the destination chain.

Function Signature:

function bridgeFee(
    uint256 dstChainId, 
    uint256 gasLimit) 
    external view returns (uint256);

Parameter	Type	Description
recipient	address	The address receiving the bridged tokens.
amount	uint256	Amount of CVE tokens to mint (in wei)

completeBridge() - (system only)

System-only function called exclusively by the Protocol Messaging Hub to complete the bridging process on the destination chain. It mints the specified amount of CVE tokens to the recipient's address. This function implements strict access control and can only be executed by the authorized Messaging Hub contract. It validates that the message comes from a legitimate source chain and includes appropriate verification. Emits a BridgeTokensComplete event upon successful completion. This function should never be called directly by users or external contracts.

Function Signature:

function completeBridge(
    address recipient, 
    uint256 amount) external;

Parameter	Type	Description
recipient	address	The address receiving the bridged tokens
amount	uint256	Amount of CVE tokens to mint (in wei)

Event Signatures

// Emitted on source chain when bridge is initiated
event BridgeTokens(
    address user, 
    uint256 chainId, 
    uint256 dstChainId, 
    uint256 amount);

// Emitted on destination chain when bridge is completed
event BridgeTokensComplete(
    address user, 
    uint256 chainId, 
    uint256 amount);