Bridge Failures in Multi-Chain Yield Farming: Recovery Methods That Actually Work

# Using Etherscan API for Ethereum transactions
curl "https://api.etherscan.io/api?module=transaction&action=gettxreceiptstatus&txhash=YOUR_TX_HASH&apikey=YOUR_API_KEY"

// Check bridge transaction status
const Web3 = require('web3');
const web3 = new Web3('YOUR_RPC_ENDPOINT');

async function checkBridgeStatus(txHash) {
    const receipt = await web3.eth.getTransactionReceipt(txHash);
    
    // Look for bridge-specific event logs
    const bridgeEvents = receipt.logs.filter(log => 
        log.address.toLowerCase() === BRIDGE_CONTRACT_ADDRESS.toLowerCase()
    );
    
    return bridgeEvents.length > 0 ? 'Bridge initiated' : 'Bridge not found';
}

// Sample event monitoring for destination chain
event TokensReleased(
    address indexed recipient,
    uint256 amount,
    bytes32 indexed depositHash
);

const { POSClient } = require('@maticnetwork/maticjs');
const { Web3ClientPlugin } = require('@maticnetwork/maticjs-web3');

// Initialize POS client
const posClient = new POSClient();
await posClient.init({
    network: 'mainnet',
    version: 'v1',
    parent: {
        provider: web3Provider,
        defaultConfig: { from: userAddress }
    },
    child: {
        provider: maticProvider,
        defaultConfig: { from: userAddress }
    }
});

// Complete stuck deposit manually
async function completeDeposit(txHash) {
    try {
        const result = await posClient.depositManager.depositEther(
            amount,
            userAddress,
            {
                from: userAddress,
                gasPrice: '30000000000' // 30 gwei
            }
        );
        
        console.log('Manual completion initiated:', result.transactionHash);
        return result;
    } catch (error) {
        console.error('Manual completion failed:', error);
    }
}

const { L1TransactionReceipt } = require('@arbitrum/sdk');

async function claimArbitrumWithdrawal(l2TxHash) {
    const l2Receipt = await l2Provider.getTransactionReceipt(l2TxHash);
    const l1TxReceipt = new L1TransactionReceipt(l2Receipt);
    
    // Wait for challenge period (7 days for mainnet)
    const messages = await l1TxReceipt.getL2ToL1Messages(l1Signer);
    
    for (const message of messages) {
        const status = await message.status(l2Provider);
        
        if (status === 'CONFIRMED') {
            const executeResult = await message.execute(l2Provider);
            console.log('Withdrawal executed:', executeResult.hash);
        }
    }
}

const MultichainSDK = require('@multichain/sdk');

async function recoverMultichainTransaction(txHash, fromChainId, toChainId) {
    const sdk = new MultichainSDK({
        chainId: fromChainId,
        rpcUrl: RPC_URLS[fromChainId]
    });
    
    // Query transaction status
    const status = await sdk.getTransactionStatus(txHash);
    
    if (status === 'PENDING' && Date.now() - status.timestamp > 3600000) { // 1 hour
        // Attempt recovery
        const recovery = await sdk.recoverTransaction({
            txHash: txHash,
            toChainId: toChainId,
            gasPrice: '50000000000' // Higher gas for priority
        });
        
        return recovery;
    }
}

const { Hop } = require('@hop-protocol/sdk');

const hop = new Hop('mainnet');

async function recoverHopTransfer(transferId) {
    const bridge = hop.connect(signer).bridge('USDC');
    
    try {
        // Get transfer status
        const transfer = await bridge.getTransfer(transferId);
        
        if (transfer.status === 'pending') {
            // Attempt to complete transfer
            const tx = await bridge.completeTransfer(transferId);
            await tx.wait();
            
            console.log('Hop transfer completed:', tx.hash);
        }
    } catch (error) {
        console.error('Hop recovery failed:', error.message);
    }
}

// Example: Direct interaction with bridge contract
interface IBridge {
    function completeTransfer(
        bytes32 transferId,
        address recipient,
        uint256 amount,
        bytes calldata proof
    ) external;
}

contract BridgeRecovery {
    IBridge public bridge;
    
    constructor(address _bridge) {
        bridge = IBridge(_bridge);
    }
    
    function emergencyComplete(
        bytes32 transferId,
        address recipient,
        uint256 amount,
        bytes calldata merkleProof
    ) external {
        // Verify caller authorization
        require(msg.sender == recipient, "Unauthorized");
        
        // Attempt completion with higher gas
        bridge.completeTransfer{gas: 500000}(
            transferId,
            recipient,
            amount,
            merkleProof
        );
    }
}

const bridgeABI = [/* Bridge contract ABI */];
const bridgeContract = new web3.eth.Contract(bridgeABI, BRIDGE_ADDRESS);

async function directBridgeCall(transferData) {
    const gasEstimate = await bridgeContract.methods
        .completeTransfer(
            transferData.id,
            transferData.recipient,
            transferData.amount,
            transferData.proof
        )
        .estimateGas({ from: userAddress });
    
    const tx = await bridgeContract.methods
        .completeTransfer(
            transferData.id,
            transferData.recipient,
            transferData.amount,
            transferData.proof
        )
        .send({
            from: userAddress,
            gas: Math.floor(gasEstimate * 1.5), // 50% buffer
            gasPrice: web3.utils.toWei('50', 'gwei')
        });
    
    return tx;
}

## Bridge Recovery Request

**Transaction Details:**
- TX Hash: 0x...
- Source Chain: Ethereum
- Destination Chain: Polygon  
- Amount: 1000 USDC
- Timestamp: 2025-07-19 14:30 UTC

**Error Description:**
Transaction shows completed on source chain but tokens not received on destination chain after 24 hours.

**Recovery Attempts:**
- [x] Status verification
- [x] Manual completion attempt
- [ ] Direct contract interaction

// Alternative bridge route implementation
const bridgeOptions = [
    { name: 'Polygon PoS', contract: '0x...', fee: 0.1 },
    { name: 'Hop Protocol', contract: '0x...', fee: 0.05 },
    { name: 'Multichain', contract: '0x...', fee: 0.15 }
];

async function attemptAlternativeBridge(amount, token, fromChain, toChain) {
    for (const bridge of bridgeOptions) {
        try {
            const quote = await getBridgeQuote(bridge.name, amount, token, fromChain, toChain);
            
            if (quote.success && quote.fee < amount * 0.02) { // Max 2% fee
                const tx = await executeBridge(bridge, amount, token, fromChain, toChain);
                
                if (tx.success) {
                    console.log(`Recovery successful via ${bridge.name}`);
                    return tx;
                }
            }
        } catch (error) {
            console.log(`${bridge.name} failed, trying next option`);
        }
    }
}

// Use arbitrage opportunities for recovery
async function arbitrageRecovery(stuckAmount, token) {
    // Find price differences between chains
    const prices = await Promise.all([
        getTokenPrice(token, 'ethereum'),
        getTokenPrice(token, 'polygon'),
        getTokenPrice(token, 'arbitrum')
    ]);
    
    // Execute arbitrage to effectively "recover" value
    const bestChain = prices.reduce((best, current, index) => {
        return current.price > best.price ? 
            { ...current, chain: ['ethereum', 'polygon', 'arbitrum'][index] } : 
            best;
    });
    
    return await executeArbitrageRecovery(stuckAmount, token, bestChain.chain);
}

// Comprehensive pre-bridge validation
async function validateBridgeTransaction(bridgeData) {
    const checks = {
        networkStatus: await checkNetworkHealth(bridgeData.sourceChain),
        gasPrice: await getOptimalGasPrice(bridgeData.sourceChain),
        bridgeCapacity: await checkBridgeLiquidity(bridgeData.bridge, bridgeData.amount),
        validatorStatus: await checkValidatorUptime(bridgeData.bridge)
    };
    
    const validationScore = calculateValidationScore(checks);
    
    return {
        safe: validationScore > 0.8,
        warnings: generateWarnings(checks),
        recommendations: getRecommendations(checks)
    };
}

function calculateValidationScore(checks) {
    const weights = {
        networkStatus: 0.3,
        gasPrice: 0.2,
        bridgeCapacity: 0.3,
        validatorStatus: 0.2
    };
    
    return Object.entries(checks).reduce((score, [key, value]) => {
        return score + (weights[key] * value.score);
    }, 0);
}

// Dynamic bridge selection based on real-time conditions
class SmartBridgeSelector {
    constructor() {
        this.bridges = new Map();
        this.performanceHistory = new Map();
    }
    
    async selectOptimalBridge(amount, token, fromChain, toChain) {
        const candidates = await this.getCandidateBridges(token, fromChain, toChain);
        
        const scored = await Promise.all(
            candidates.map(async (bridge) => ({
                bridge,
                score: await this.scoreBridge(bridge, amount, token)
            }))
        );
        
        return scored
            .sort((a, b) => b.score - a.score)
            .slice(0, 3); // Return top 3 options
    }
    
    async scoreBridge(bridge, amount, token) {
        const metrics = await Promise.all([
            this.getReliabilityScore(bridge),
            this.getSpeedScore(bridge),
            this.getCostScore(bridge, amount, token),
            this.getLiquidityScore(bridge, amount, token)
        ]);
        
        // Weighted scoring: Reliability 40%, Speed 25%, Cost 20%, Liquidity 15%
        return metrics[0] * 0.4 + metrics[1] * 0.25 + metrics[2] * 0.2 + metrics[3] * 0.15;
    }
}

// Automated monitoring and recovery system
class BridgeMonitor {
    constructor() {
        this.pendingTransactions = new Map();
        this.recoveryStrategies = [
            this.retryTransaction,
            this.useAlternativeBridge,
            this.contactSupport
        ];
    }
    
    async monitorTransaction(txHash, bridgeType, timeout = 3600000) { // 1 hour default
        const transaction = {
            hash: txHash,
            bridgeType,
            timestamp: Date.now(),
            timeout,
            status: 'pending'
        };
        
        this.pendingTransactions.set(txHash, transaction);
        
        // Start monitoring
        setTimeout(() => this.initiateRecovery(txHash), timeout);
        
        return this.watchTransaction(txHash);
    }
    
    async initiateRecovery(txHash) {
        const transaction = this.pendingTransactions.get(txHash);
        
        if (transaction.status === 'pending') {
            for (const strategy of this.recoveryStrategies) {
                try {
                    const result = await strategy.call(this, transaction);
                    if (result.success) {
                        transaction.status = 'recovered';
                        break;
                    }
                } catch (error) {
                    console.log(`Recovery strategy failed: ${error.message}`);
                }
            }
        }
    }
}

// Example bot configuration
const recoveryBot = {
    enableAutoRecovery: true,
    maxGasPrice: web3.utils.toWei('100', 'gwei'),
    retryAttempts: 5,
    supportedBridges: ['polygon', 'arbitrum', 'optimism'],
    notificationChannels: ['email', 'discord', 'telegram']
};

// Calculate if recovery attempt is economically viable
function calculateRecoveryROI(stuckAmount, recoveryMethod) {
    const methods = {
        manual: { successRate: 0.7, avgCost: 30, avgTime: 24 },
        protocol: { successRate: 0.85, avgCost: 60, avgTime: 12 },
        direct: { successRate: 0.9, avgCost: 125, avgTime: 3 },
        professional: { successRate: 0.95, avgCost: stuckAmount * 0.05, avgTime: 48 }
    };
    
    const method = methods[recoveryMethod];
    const expectedRecovery = stuckAmount * method.successRate;
    const netRecovery = expectedRecovery - method.avgCost;
    const roi = (netRecovery / stuckAmount) * 100;
    
    return {
        expectedRecovery,
        netRecovery,
        roi,
        recommendation: roi > 90 ? 'Proceed' : 'Consider alternatives'
    };
}

// Comprehensive bridge health monitoring system
class BridgeHealthMonitor {
    constructor() {
        this.healthChecks = new Map();
        this.alertThresholds = {
            responseTime: 30000, // 30 seconds
            failureRate: 0.05,   // 5%
            liquidityRatio: 0.8  // 80%
        };
    }
    
    async performHealthCheck(bridge) {
        const startTime = Date.now();
        
        try {
            const [liquidity, validators, recentTxs] = await Promise.all([
                this.checkLiquidity(bridge),
                this.checkValidators(bridge),
                this.checkRecentTransactions(bridge)
            ]);
            
            const responseTime = Date.now() - startTime;
            
            const health = {
                bridge: bridge.name,
                timestamp: Date.now(),
                responseTime,
                liquidity: liquidity.ratio,
                validatorUptime: validators.uptimePercent,
                recentFailureRate: recentTxs.failureRate,
                overall: this.calculateOverallHealth(liquidity, validators, recentTxs, responseTime)
            };
            
            this.healthChecks.set(bridge.name, health);
            
            if (this.shouldAlert(health)) {
                await this.sendAlert(health);
            }
            
            return health;
        } catch (error) {
            console.error(`Health check failed for ${bridge.name}:`, error);
            return null;
        }
    }
    
    shouldAlert(health) {
        return health.responseTime > this.alertThresholds.responseTime ||
               health.recentFailureRate > this.alertThresholds.failureRate ||
               health.liquidity < this.alertThresholds.liquidityRatio;
    }
}

// Multi-channel alert system
const alertConfig = {
    channels: {
        email: {
            enabled: true,
            recipients: ['trader@example.com'],
            severity: 'medium' // low, medium, high, critical
        },
        discord: {
            enabled: true,
            webhook: 'https://discord.com/api/webhooks/...',
            severity: 'high'
        },
        telegram: {
            enabled: true,
            chatId: '123456789',
            severity: 'critical'
        }
    },
    conditions: {
        bridgeFailure: ['email', 'discord'],
        highGasPrice: ['email'],
        lowLiquidity: ['discord'],
        validatorIssues: ['telegram', 'discord']
    }
};