Bridge Facet

The Bridge Facet handles the transfer of collateral to and from registered bridge addresses. It allows users to send funds to a bridge for cross-chain movement and to claim funds received from a bridge on the destination chain. Administrators can suspend and restore bridge transactions for dispute resolution. The underlying logic is implemented in the BridgeFacetImpl library.

In v0.8.5, the Bridge Facet is retained alongside the new Withdraw System (see WithdrawFacet). The new withdraw system introduces a multi-provider architecture with express and virtual providers for cross-chain withdrawals and instant payouts. The Bridge Facet serves as the direct bridge transfer mechanism, while the WithdrawFacet handles the broader cooldown-based withdrawal flows with provider integration.

Overview

The Bridge Facet provides the following key functionalities:

• Transfer to Bridge: Users send collateral from their protocol balance to a registered bridge address, initiating a cross-chain transfer.

• Withdraw Received Bridge Value: Users claim funds that have arrived via a bridge transaction on the destination chain.

• Transaction Suspension: A suspender role can freeze suspicious bridge transactions pending investigation.

• Transaction Restoration: A dispute role can restore suspended transactions with a validated amount, resolving disputes.

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transferToBridge()

Transfers a specified amount of collateral from the caller's balance to a registered bridge address.

Function Signature:

function transferToBridge(uint256 amount, address bridgeAddress) external whenNotAccountingPaused notSuspended(signer);

Parameters:

• amount: The amount to transfer (in collateral decimals).

• bridgeAddress: The address of the registered bridge to receive the funds.

Example:

// Transfer 500 tokens to a bridge for cross-chain movement
symmioDiamond.transferToBridge(500, bridgeAddress);

Events Emitted:

• TransferToBridge(address sender, uint256 amount, address bridgeAddress, uint256 transactionId)

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withdrawReceivedBridgeValue()

Claims the funds associated with a specific bridge transaction that has been received on this chain.

Function Signature:

function withdrawReceivedBridgeValue(uint256 transactionId) external whenNotAccountingPaused notSuspended(msg.sender);

Parameters:

• transactionId: The ID of the bridge transaction to claim.

Example:

// Claim funds from a completed bridge transaction
symmioDiamond.withdrawReceivedBridgeValue(transactionId);

Events Emitted:

• WithdrawReceivedBridgeValue(uint256 transactionId)

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withdrawReceivedBridgeValues()

Claims funds from multiple bridge transactions in a single call.

Function Signature:

function withdrawReceivedBridgeValues(uint256[] memory transactionIds) external whenNotAccountingPaused notSuspended(msg.sender);

Parameters:

• transactionIds: An array of bridge transaction IDs to claim.

Events Emitted:

• WithdrawReceivedBridgeValues(uint256[] transactionIds)

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suspendBridgeTransaction()

Suspends a specific bridge transaction, freezing it pending investigation. Only callable by the suspender role.

Function Signature:

function suspendBridgeTransaction(uint256 transactionId) external onlyRole(SUSPENDER_ROLE);

Parameters:

• transactionId: The ID of the bridge transaction to suspend.

Access: Requires SUSPENDER_ROLE.

Events Emitted:

• SuspendBridgeTransaction(uint256 transactionId)

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restoreBridgeTransaction()

Restores a previously suspended bridge transaction with a validated amount. This resolves a dispute by confirming the correct transfer amount, which may differ from the originally reported amount.

Function Signature:

function restoreBridgeTransaction(uint256 transactionId, uint256 validAmount) external onlyRole(DISPUTE_ROLE);

Parameters:

• transactionId: The ID of the suspended bridge transaction to restore.

• validAmount: The validated amount to associate with the restored transaction.

Access: Requires DISPUTE_ROLE.

Events Emitted:

• RestoreBridgeTransaction(uint256 transactionId, uint256 validAmount)