Data Providers

Overview

Profitmaker supports multiple data providers that fetch market data from exchanges. The provider system abstracts away the difference between running CCXT in the browser vs. on a server.

Provider Types

Type	Class	Location	Description
ccxt-browser	CCXTBrowserProviderImpl	packages/core/src/ccxtBrowserProvider.ts	CCXT runs directly in the browser
ccxt-server	CCXTServerProviderImpl	packages/core/src/ccxtServerProvider.ts	CCXT runs on Express server, browser sends HTTP requests
marketmaker.cc	—	Planned	External data provider
custom-server-with-adapter	—	Planned	Custom server with adapter interface

Browser Provider (default)

The browser provider is created automatically on first load:

{
  id: 'universal-browser',
  type: 'ccxt-browser',
  name: 'Universal Browser Provider',
  status: 'connected',
  exchanges: ['*'],    // supports all exchanges
  priority: 100,       // low priority (fallback)
  config: { sandbox: false }
}

How it works:

1. CCXT library loads in the browser
2. Exchange instances are created and cached in ccxtInstanceManager
3. REST calls go directly from browser to exchange API
4. WebSocket connections (CCXT Pro) also run in browser

Limitations:

• Some exchanges block browser requests (CORS)
• Browser has limited connection capacity
• API keys are used in browser memory (encrypted at rest in localStorage)

Server Provider

The server provider routes all CCXT operations through the Express server, bypassing CORS restrictions.

Setup:

1. Start the server: bun server:dev
2. Add a server provider in the UI (Data Provider Settings widget) or programmatically:

const provider = dataProviderStore.getState().createProvider(
  'ccxt-server',
  'My Server Provider',
  ['binance', 'bybit'],  // or ['*'] for all
  {
    serverUrl: 'http://localhost:3001',
    apiToken: 'your-secret-token'
  }
);

How it works:

1. Browser sends HTTP POST to http://localhost:3001/api/exchange/<method>
2. Server creates/reuses a CCXT instance
3. Server calls the exchange API (no CORS issues)
4. Server returns the response to the browser

Advantages:

• No CORS problems
• Server can run CCXT Pro for WebSocket streaming
• API keys can stay on the server (not in browser)
• Server can be deployed separately

Provider Selection

When a widget subscribes to data, the store picks the best provider:

1. Find all providers that support the requested exchange
2. Sort by priority (lower number = higher priority)
3. Use the first enabled provider

You can control this by:

• Setting provider priority: updateProviderPriority(providerId, priority)
• Enabling/disabling providers: toggleProvider(providerId)
• Restricting exchanges per provider: set exchanges array

Data Types

DataType	REST Method	WebSocket Method	Description
candles	fetchOHLCV	watchOHLCV	OHLCV candlestick data
trades	fetchTrades	watchTrades	Recent trades feed
orderbook	fetchOrderBook	watchOrderBook	Order book depth
ticker	fetchTicker	watchTicker	24h ticker summary
balance	fetchBalance	watchBalance	Account balances (requires API key)

WebSocket vs REST

The dataFetchSettings.method controls the default strategy:

WebSocket mode ('websocket')

• Real-time streaming via CCXT Pro
• Lower latency, more efficient
• Requires CCXT Pro support on the exchange
• Falls back to REST if WebSocket unavailable

REST mode ('rest')

• Polling at configurable intervals
• Works with all exchanges
• Default intervals (configurable per data type):

restIntervals: {
  trades: 1000,     // 1 second
  candles: 5000,    // 5 seconds
  orderbook: 500,   // 0.5 seconds
  balance: 30000,   // 30 seconds
  ticker: 600000    // 10 minutes
}

Fallback

If WebSocket is selected but the exchange doesn’t support it for a given data type, the system automatically falls back to REST polling.

Subscription System

Subscriptions are deduplicated by key: {exchange}:{market}:{symbol}:{dataType}:{timeframe}

// Widget subscribes
await subscribe(
  'chart-widget-abc',    // subscriberId (unique per widget instance)
  'binance',             // exchange
  'BTC/USDT',           // symbol
  'candles',            // dataType
  '1h',                 // timeframe (for candles)
  'spot'                // market type
);

// Widget unsubscribes on unmount
unsubscribe('chart-widget-abc', 'binance', 'BTC/USDT', 'candles', '1h', 'spot');

Multiple widgets subscribing to the same key share one data stream. The stream is closed only when the last subscriber unsubscribes.

Data Initialization

Widgets typically need initial data before streaming begins. Use the initialize* methods:

// Fetch initial candles for a chart
const candles = await initializeChartData('binance', 'BTC/USDT', '1h', 'spot');

// Fetch initial trades
const trades = await initializeTradesData('binance', 'BTC/USDT', 'spot', 50);

// Fetch initial orderbook
const orderbook = await initializeOrderBookData('binance', 'BTC/USDT', 'spot');

// Load more historical candles (infinite scroll)
const older = await loadHistoricalCandles('binance', 'BTC/USDT', '1h', 'spot', beforeTimestamp);

Chart Update Events

The store includes an event system specifically for Chart widgets. When new candles arrive via WebSocket, the store emits events that Night Vision chart instances can listen to:

// Register listener
addChartUpdateListener('binance', 'BTC/USDT', '1h', 'spot', listener);

// Remove listener
removeChartUpdateListener('binance', 'BTC/USDT', '1h', 'spot', listener);

CCXT Instance Management

Exchange instances are cached in packages/core/src/ccxtInstanceManager.ts:

• Instances are keyed by: {exchangeId}:{marketType}:{ccxtType}:{sandbox}:{apiKeyPrefix}
• Server-side cache TTL: 24 hours, cleanup every 10 minutes
• Browser-side: instances persist for the page session
• Markets are loaded on first instance creation (exchange.loadMarkets())

Intelligent Method Selection

For order book fetching, the store includes selectOptimalOrderBookMethod() which checks exchange capabilities and selects the best available method (some exchanges support fetchOrderBook but not watchOrderBook, or have different depth limits).

Supported Exchanges

CCXT v4.4 supports 100+ exchanges. Common ones:

binance, bybit, okx, bitget, kucoin, gate, mexc, huobi, kraken, coinbase, bitfinex, bitmex, phemex, deribit, and many more.

Use getAllSupportedExchanges() to get the full list from the current CCXT version.