Production Best Practices

Building production-ready applications with SwapKit requires careful attention to security, performance, and user experience. This guide covers essential best practices.

Security

API Key Management

For frontend applications, use a backend proxy to keep API keys secure:

// Frontend
const quote = await fetch('/api/swap-quote', {
  method: 'POST',
  body: JSON.stringify(quoteParams)
}).then(r => r.json());

// Backend API route
import { SwapKitApi } from '@swapkit/helpers/api';

export async function POST(request: Request) {
  const params = await request.json();
  
  // Add API key server-side
  const quote = await SwapKitApi.getSwapQuote({
    ...params,
    apiKey: process.env.SWAPKIT_API_KEY
  });
  
  return Response.json(quote);
}

Private Key Handling

Always use secure wallet connections instead of handling private keys directly:

import { createSwapKit, Chain } from '@swapkit/sdk';

const swapKit = createSwapKit();

// ✅ Use secure wallet connections
await swapKit.connectEVMWallet([Chain.Ethereum]); // MetaMask
await swapKit.connectLedger([Chain.Bitcoin]);      // Hardware wallet
await swapKit.connectTrezor([Chain.Bitcoin]);      // Trezor wallet

Input Validation

Always validate user inputs:

import { createSwapKit, SwapKitError } from '@swapkit/sdk';

const swapKit = createSwapKit();

function validateSwapInput(params: any): void {
  // Validate addresses
  if (!swapKit.validateAddress(params.recipient, params.chain)) {
    throw new SwapKitError('core_swap_invalid_params', {
      message: 'Invalid recipient address'
    });
  }
  
  // Validate amounts
  const amount = Number(params.amount);
  if (isNaN(amount) || amount <= 0) {
    throw new SwapKitError('core_swap_invalid_params', {
      message: 'Invalid amount'
    });
  }
  
  // Validate slippage
  if (params.slippage < 0 || params.slippage > 50) {
    throw new SwapKitError('core_swap_invalid_params', {
      message: 'Slippage must be between 0 and 50%'
    });
  }
}

Performance Optimization

Bundle Size Reduction

Use the modular approach for smaller bundles:

Modular (Recommended)

// Import only what you need
import { SwapKit, ThorchainPlugin, evmWallet } from '@swapkit/sdk';

const swapKit = SwapKit({
  plugins: { ...ThorchainPlugin },
  wallets: { ...evmWallet }
});

All-in-one

// Imports everything - larger bundle
import { createSwapKit } from '@swapkit/sdk';

const swapKit = createSwapKit();

Lazy Loading Toolboxes

Load toolboxes only when needed:

import { Chain } from '@swapkit/sdk';

// Lazy load toolboxes
async function getToolboxForChain(chain: Chain) {
  switch (chain) {
    case Chain.Ethereum:
      const { getEvmToolbox } = await import('@swapkit/sdk');
      return getEvmToolbox(chain);
    
    case Chain.Bitcoin:
      const { getUtxoToolbox } = await import('@swapkit/sdk');
      return getUtxoToolbox(chain);
    
    default:
      const { getToolbox } = await import('@swapkit/sdk');
      return getToolbox(chain);
  }
}

Request Caching

Implement caching for frequently accessed data:

class SwapKitCache {
  private cache = new Map<string, { data: any; timestamp: number }>();
  private ttl: Record<string, number> = {
    price: 60_000,      // 1 minute
    balance: 300_000,   // 5 minutes
    quote: 30_000,      // 30 seconds
  };
  
  async get<T>(
    key: string, 
    type: keyof typeof this.ttl,
    fetcher: () => Promise<T>
  ): Promise<T> {
    const cached = this.cache.get(key);
    const now = Date.now();
    
    if (cached && now - cached.timestamp < this.ttl[type]) {
      return cached.data;
    }
    
    const data = await fetcher();
    this.cache.set(key, { data, timestamp: now });
    return data;
  }
}

const cache = new SwapKitCache();

// Use cache for prices
const price = await cache.get(
  `price_${asset}`,
  'price',
  async () => {
    const { SwapKitApi } = await import('@swapkit/helpers/api');
    return SwapKitApi.getPrice(asset);
  }
);

Batch Operations

Batch multiple operations for efficiency:

import { Chain } from '@swapkit/sdk';

// ❌ Inefficient - multiple sequential calls
const ethBalance = await swapKit.getBalance(Chain.Ethereum);
const btcBalance = await swapKit.getBalance(Chain.Bitcoin);
const avaxBalance = await swapKit.getBalance(Chain.Avalanche);

// ✅ Efficient - parallel calls
const chains = [Chain.Ethereum, Chain.Bitcoin, Chain.Avalanche];
const balances = await Promise.all(
  chains.map(chain => swapKit.getBalance(chain))
);

Error Handling

Comprehensive Error Handling

Handle all error scenarios gracefully:

import { SwapKitError } from '@swapkit/sdk';

async function executeSwap(route: SwapRoute) {
  try {
    const txHash = await swapKit.swap({ route });
    return { success: true, txHash };
  } catch (error) {
    if (error instanceof SwapKitError) {
      // Handle SwapKit-specific errors
      switch (error.code) {
        case 'wallet_not_connected':
          return { success: false, error: 'Please connect your wallet' };
        
        case 'insufficient_balance':
          return { success: false, error: 'Insufficient balance' };
        
        case 'user_rejected':
          return { success: false, error: 'Transaction cancelled' };
        
        default:
          return { success: false, error: error.message };
      }
    }
    
    // Handle network errors
    if (error instanceof Error && error.message.includes('network')) {
      return { success: false, error: 'Network error. Please try again.' };
    }
    
    // Unknown error
    console.error('Unexpected error:', error);
    return { success: false, error: 'An unexpected error occurred' };
  }
}

Retry Logic

Implement retry logic for transient failures:

import { SwapKitError, SwapKitApi } from '@swapkit/sdk';

async function withRetry<T>(
  fn: () => Promise<T>,
  options = { maxRetries: 3, delay: 1000 }
): Promise<T> {
  let lastError: Error;
  
  for (let i = 0; i <= options.maxRetries; i++) {
    try {
      return await fn();
    } catch (error) {
      lastError = error as Error;
      
      // Don't retry user rejections
      if (error instanceof SwapKitError && 
          error.code === 'user_rejected') {
        throw error;
      }
      
      // Wait before retry
      if (i < options.maxRetries) {
        await new Promise(r => setTimeout(r, options.delay * (i + 1)));
      }
    }
  }
  
  throw lastError!;
}

// Usage
const quote = await withRetry(() => 
  SwapKitApi.getSwapQuote(params)
);

User Experience

Loading States

Provide clear feedback during operations:

import { SwapKitApi } from '@swapkit/sdk';

interface SwapState {
  status: 'idle' | 'quoting' | 'approving' | 'swapping' | 'success' | 'error';
  message?: string;
  txHash?: string;
}

async function performSwap(params: SwapParams) {
  const setState = (update: Partial<SwapState>) => {
    // Update UI state
  };
  
  try {
    setState({ status: 'quoting', message: 'Getting best price...' });
    const quote = await SwapKitApi.getSwapQuote(params);
    
    setState({ status: 'approving', message: 'Approving tokens...' });
    await swapKit.approveAssetValue(assetValue);
    
    setState({ status: 'swapping', message: 'Executing swap...' });
    const txHash = await swapKit.swap({ route: quote.routes[0] });
    
    setState({ status: 'success', txHash });
  } catch (error) {
    setState({ 
      status: 'error', 
      message: getErrorMessage(error) 
    });
  }
}

Transaction Tracking

Track transaction status for better UX:

import { Chain, SwapKitApi } from '@swapkit/sdk';

async function trackTransaction(
  txHash: string, 
  chain: Chain,
  onUpdate: (status: string) => void
) {
  let attempts = 0;
  const maxAttempts = 60; // 5 minutes with 5s intervals
  
  while (attempts < maxAttempts) {
    try {
      const status = await SwapKitApi.getTrackerDetails({ txHash, chain });
      
      onUpdate(status.status);
      
      if (status.status === 'completed' || status.status === 'failed') {
        return status;
      }
    } catch (error) {
      // Continue polling
    }
    
    await new Promise(r => setTimeout(r, 5000));
    attempts++;
  }
  
  throw new Error('Transaction tracking timeout');
}

Network Configuration

RPC Failover

Configure multiple RPC endpoints for reliability:

import { Chain } from '@swapkit/sdk';

const rpcEndpoints = {
  [Chain.Ethereum]: [
    process.env.ALCHEMY_ETH_RPC,
    process.env.INFURA_ETH_RPC,
    'https://eth.llamarpc.com'
  ].filter(Boolean),
  
  [Chain.Avalanche]: [
    process.env.AVALANCHE_RPC,
    'https://api.avax.network/ext/bc/C/rpc'
  ].filter(Boolean)
};

// Failover logic
async function getRpcUrl(chain: Chain): Promise<string> {
  const endpoints = rpcEndpoints[chain] || [];
  
  for (const url of endpoints) {
    try {
      const response = await fetch(url, {
        method: 'POST',
        body: JSON.stringify({ method: 'eth_blockNumber', params: [], id: 1 })
      });
      
      if (response.ok) return url;
    } catch {
      continue;
    }
  }
  
  throw new Error(`No working RPC for ${chain}`);
}

Gas Price Management

Implement dynamic gas pricing:

import { SwapKitApi } from '@swapkit/sdk';

async function getOptimalGasPrice(chain: Chain, priority: 'low' | 'medium' | 'high') {
  const gasRates = await SwapKitApi.getGasRate(chain);
  
  const multipliers = {
    low: 0.9,
    medium: 1.0,
    high: 1.5
  };
  
  return {
    maxFeePerGas: Math.floor(Number(gasRates) * multipliers[priority]),
    maxPriorityFeePerGas: Math.floor(Number(gasRates) * 0.1)
  };
}

Monitoring & Analytics

Error Tracking

Track errors for debugging:

import * as Sentry from '@sentry/browser';

// Initialize error tracking
Sentry.init({
  dsn: process.env.SENTRY_DSN,
  environment: process.env.NODE_ENV,
  beforeSend(event, hint) {
    // Don't send sensitive data
    if (event.request?.data) {
      delete event.request.data.privateKey;
      delete event.request.data.mnemonic;
    }
    return event;
  }
});

// Track SwapKit errors
try {
  await swapKit.swap({ route });
} catch (error) {
  Sentry.captureException(error, {
    tags: {
      chain: route.sellAsset.split('.')[0],
      provider: route.providers[0]
    }
  });
  throw error;
}

Performance Monitoring

Track key metrics:

class PerformanceTracker {
  track(operation: string, fn: () => Promise<any>) {
    const start = performance.now();
    
    return fn()
      .then(result => {
        const duration = performance.now() - start;
        this.report(operation, duration, 'success');
        return result;
      })
      .catch(error => {
        const duration = performance.now() - start;
        this.report(operation, duration, 'error');
        throw error;
      });
  }
  
  private report(operation: string, duration: number, status: string) {
    // Send to analytics
    analytics.track('operation_performance', {
      operation,
      duration,
      status
    });
  }
}

const tracker = new PerformanceTracker();

// Track swap performance
const txHash = await tracker.track('swap', () => 
  swapKit.swap({ route })
);

Deployment Checklist

Before deploying to production:

• Environment Variables: All sensitive data in env vars
• API Keys: Production keys configured, not exposed
• Error Handling: Comprehensive error handling implemented
• Monitoring: Error tracking and analytics configured
• Performance: Bundle optimized, lazy loading implemented
• Security: Input validation, secure wallet handling
• Testing: All features tested on mainnet
• Documentation: User guides and FAQs prepared
• Support: Support channels established
• Compliance: Legal requirements addressed

Testing in Production

Gradual Rollout

// Feature flags for gradual rollout
const features = {
  newSwapFlow: process.env.ENABLE_NEW_SWAP_FLOW === 'true',
  thorchainSwaps: process.env.ENABLE_THORCHAIN === 'true'
};

if (features.newSwapFlow) {
  // New implementation
} else {
  // Stable implementation
}

Health Checks

import { SwapKitApi, Chain } from '@swapkit/sdk';

async function healthCheck(): Promise<HealthStatus> {
  const checks = await Promise.allSettled([
    SwapKitApi.getPrice('ETH'),
    swapKit.validateAddress('0x...', Chain.Ethereum),
    fetch(rpcUrls[Chain.Ethereum])
  ]);
  
  return {
    api: checks[0].status === 'fulfilled',
    sdk: checks[1].status === 'fulfilled',
    rpc: checks[2].status === 'fulfilled'
  };
}

Next Steps

• Review Security considerations
• Implement Advanced Features
• Monitor performance with API Reference