Step 5: Transaction Monitoring & Status Tracking

async function waitForConfirmation(orderId) {
  while (true) {
    const response = await fetch(
      `https://api.unikron.ch/api/v1/mev/orders/${orderId}`,
      { headers: { "X-API-Key": "YOUR_KEY" } }
    );
 
    const { ok, data } = await response.json();
 
    // Log current transaction state
    console.log(`ORDER_STATUS: ${data.status.toUpperCase()}`);
    console.log(`TIMESTAMP: ${new Date().toISOString()}`);
 
    // Terminal states
    if (data.status === "confirmed") {
      console.log(`TRANSACTION_CONFIRMED: ${data.txHash}`);
      console.log(`BLOCK_NUMBER: ${data.blockNumber}`);
      console.log(`ETHERSCAN_URL: https://etherscan.io/tx/${data.txHash}`);
      return {
        success: true,
        txHash: data.txHash,
        blockNumber: data.blockNumber,
        gasUsed: data.gasUsed,
        effectiveGasPrice: data.effectiveGasPrice,
      };
    }
 
    if (data.status === "failed") {
      console.error(`TRANSACTION_FAILED: ${data.error}`);
      console.error(`FAILURE_REASON: ${data.revertReason || "Unknown"}`);
      throw new Error(`Transaction failed: ${data.error}`);
    }
 
    // Polling interval: 10 seconds (complies with rate limits)
    await new Promise((resolve) => setTimeout(resolve, 10000));
  }
}
 
await waitForConfirmation(order.orderId);

const POLLING_CONFIG = {
  interval: 10000, // 10 seconds (rate limit compliant)
  timeout: 300000, // 5 minutes maximum wait
  maxRetries: 3, // Retry failed API calls
  exponentialBackoff: true,
};

// Example: DataDog/NewRelic integration
async function monitorTransaction(orderId) {
  const startTime = Date.now();
 
  try {
    const result = await waitForConfirmation(orderId);
 
    // Success metrics
    metrics.recordTransactionSuccess({
      orderId,
      duration: Date.now() - startTime,
      gasUsed: result.gasUsed,
      effectiveGasPrice: result.effectiveGasPrice,
    });
 
    return result;
  } catch (error) {
    // Failure metrics and alerting
    metrics.recordTransactionFailure({
      orderId,
      error: error.message,
      duration: Date.now() - startTime,
    });
 
    alerts.trigger("transaction_failed", { orderId, error });
    throw error;
  }
}