candles

Instructions

Implementation Reference

• index.js:80-99 (handler)

  The async function getCryptoCandles(symbol, interval, days) fetches OHLCV candlestick data from the CoinGecko API and maps the response to {time, open, high, low, close} objects.

  async function getCryptoCandles(symbol, interval = '1h', days = 7) {
    const id = symbol.toLowerCase().replace('usdt', '').replace('usd', '');
    const idMap = {
      btc: 'bitcoin', eth: 'ethereum', sol: 'solana', doge: 'dogecoin',
      xrp: 'ripple', bnb: 'binancecoin', ada: 'cardano', avax: 'avalanche-2',
    };
    const coinId = idMap[id] || id;
  
    const data = await fetch(
      `https://api.coingecko.com/api/v3/coins/${coinId}/ohlc?vs_currency=usd&days=${days}`
    );
  
    return data.map(c => ({
      time: new Date(c[0]).toISOString(),
      open: c[1],
      high: c[2],
      low: c[3],
      close: c[4],
    }));
  }

• index.js:249-259 (schema)

  Tool registration definition for 'candles' with inputSchema requiring 'symbol' (string) and optional 'days' (number).

  {
    name: 'candles',
    description: 'Get OHLCV candlestick data for any crypto. Returns open, high, low, close for each period.',
    inputSchema: {
      type: 'object',
      properties: {
        symbol: { type: 'string', description: 'Crypto symbol' },
        days: { type: 'number', description: 'Number of days of history (1, 7, 14, 30, 90, 180, 365). Default: 7' }
      },
      required: ['symbol']
    }

• index.js:236-316 (registration)

  The getToolDefinitions() method returns all tool definitions including 'candles'. The tools/list MCP method calls this to register tools.

  getToolDefinitions() {
    return [
      {
        name: 'price',
        description: 'Get current price, 24h change, volume, market cap for any cryptocurrency. Examples: BTC, ETH, SOL, DOGE.',
        inputSchema: {
          type: 'object',
          properties: {
            symbol: { type: 'string', description: 'Crypto symbol (BTC, ETH, SOL, DOGE, etc.)' }
          },
          required: ['symbol']
        }
      },
      {
        name: 'candles',
        description: 'Get OHLCV candlestick data for any crypto. Returns open, high, low, close for each period.',
        inputSchema: {
          type: 'object',
          properties: {
            symbol: { type: 'string', description: 'Crypto symbol' },
            days: { type: 'number', description: 'Number of days of history (1, 7, 14, 30, 90, 180, 365). Default: 7' }
          },
          required: ['symbol']
        }
      },
      {
        name: 'order_book',
        description: 'Get live order book — top 20 bids and asks with spread. Shows market depth and liquidity.',
        inputSchema: {
          type: 'object',
          properties: {
            symbol: { type: 'string', description: 'Trading pair (BTC, ETHUSDT, etc.)' }
          },
          required: ['symbol']
        }
      },
      {
        name: 'market_cap',
        description: 'Get top cryptocurrencies ranked by market cap with prices, volumes, and 24h changes.',
        inputSchema: {
          type: 'object',
          properties: {
            limit: { type: 'number', description: 'Number of coins to return (default: 20, max: 100)' }
          }
        }
      },
      {
        name: 'trending',
        description: 'Get trending cryptocurrencies right now — what people are searching for and trading.',
        inputSchema: { type: 'object', properties: {} }
      },
      {
        name: 'analyze',
        description: 'Technical analysis for any crypto: RSI, SMA, volatility, z-score, trend direction. Actionable signals included.',
        inputSchema: {
          type: 'object',
          properties: {
            symbol: { type: 'string', description: 'Crypto symbol' },
            days: { type: 'number', description: 'Lookback period in days (default: 30)' }
          },
          required: ['symbol']
        }
      },
      {
        name: 'compare',
        description: 'Compare multiple assets side by side — prices, changes, market caps.',
        inputSchema: {
          type: 'object',
          properties: {
            symbols: { type: 'string', description: 'Comma-separated symbols (e.g., "BTC,ETH,SOL")' }
          },
          required: ['symbols']
        }
      },
      {
        name: 'feargreed',
        description: 'Crypto Fear & Greed Index — market sentiment indicator. Shows last 7 days.',
        inputSchema: { type: 'object', properties: {} }
      }
    ];
  }

• index.js:318-324 (registration)

  The handleToolCall() method dispatches the 'candles' case to getCryptoCandles(args.symbol, '1h', args.days || 7). The interval is hardcoded to '1h'.

  async handleToolCall(name, args) {
    switch (name) {
      case 'price':
        return await getCryptoPrice(args.symbol);
  
      case 'candles':
        return await getCryptoCandles(args.symbol, '1h', args.days || 7);

• index.js:31-44 (helper)

  The fetch() helper function is used by getCryptoCandles to make HTTPS requests with JSON parsing and timeout handling.

  function fetch(url) {
    return new Promise((resolve, reject) => {
      const req = https.get(url, { headers: { 'User-Agent': 'mcp-market-data/0.1' } }, (res) => {
        let data = '';
        res.on('data', chunk => data += chunk);
        res.on('end', () => {
          try { resolve(JSON.parse(data)); }
          catch (e) { reject(new Error(`Parse error: ${data.slice(0, 200)}`)); }
        });
      });
      req.on('error', reject);
      req.setTimeout(15000, () => { req.destroy(); reject(new Error('Timeout')); });
    });
  }