komodo_cex_market_data 0.0.3+1

CEX market data repositories and strategies with fallbacks for Komodo SDK apps.

Komodo CEX Market Data

Composable repositories and strategies to fetch cryptocurrency prices from multiple sources with fallbacks and health-aware selection.

Sources supported:

• Komodo price service
• Binance
• CoinGecko

Install

dart pub add komodo_cex_market_data

Concepts

• Repositories implement a common interface to fetch prices and lists
• A selection strategy chooses the best repository per request
• Failures trigger temporary backoff; callers transparently fall back

Quick start (standalone)

import 'package:get_it/get_it.dart';
import 'package:komodo_cex_market_data/komodo_cex_market_data.dart';

final di = GetIt.asNewInstance();

// Configure providers/repos/strategy
await MarketDataBootstrap.register(di, config: const MarketDataConfig());

final repos = await MarketDataBootstrap.buildRepositoryList(
  di,
  const MarketDataConfig(),
);

final manager = CexMarketDataManager(
  priceRepositories: repos,
  selectionStrategy: di<RepositorySelectionStrategy>(),
);
await manager.init();

// Fetch current price (see komodo_defi_types AssetId for details)
// In practice, you will receive an AssetId from the SDK or coins package
final price = await manager.fiatPrice(
  AssetId.parse({
    'coin': 'KMD',
    'protocol': {'type': 'UTXO'},
  }),
  quoteCurrency: Stablecoin.usdt,
);

With the SDK

KomodoDefiSdk wires this package for you. Use sdk.marketData:

final price = await sdk.marketData.fiatPrice(asset.id);
final change24h = await sdk.marketData.priceChange24h(asset.id);

Customization

const cfg = MarketDataConfig(
  enableKomodoPrice: true,
  enableBinance: true,
  enableCoinGecko: true,
  repositoryPriority: [
    RepositoryType.komodoPrice,
    RepositoryType.binance,
    RepositoryType.coinGecko,
  ],
  customRepositories: [],
);

Rate Limit Handling

The package includes intelligent rate limit handling to prevent API quota exhaustion and service disruption:

Automatic 429 Detection

When a repository returns a 429 (Too Many Requests) response, it is immediately marked as unhealthy and excluded from requests for 5 minutes. The system detects rate limiting errors by checking for:

• HTTP status code 429 in exception messages
• Text patterns like "too many requests" or "rate limit"

Fallback Behavior

// If CoinGecko hits rate limit, automatically falls back to Binance
final price = await manager.fiatPrice(assetId);
// No manual intervention required - fallback is transparent

Repository Health Recovery

Rate-limited repositories automatically recover after the backoff period:

// After 5 minutes, CoinGecko becomes available again
// Next request will include it in the selection pool
final newPrice = await manager.fiatPrice(assetId);

Monitoring Rate Limits

You can check repository health status (mainly useful for testing):

// Check if a repository is healthy (not rate-limited)
final isHealthy = manager.isRepositoryHealthyForTest(repository);

License

MIT