VN Stock API MCP Server

Instructions

Implementation Reference

• src/index.ts:180-209 (registration)

  Tool registration with name 'analyze_doji_pattern', description, and input schema definition.
  name: "analyze_doji_pattern", description: "Analyze Doji candlestick patterns in stock price charts. Doji patterns indicate market indecision and potential trend reversals. Detects various types of Doji patterns including Standard Doji, Long-legged Doji, Dragonfly Doji, Gravestone Doji, and Four Price Doji.", inputSchema: { type: "object", properties: { symbol: { type: "string", description: "Stock symbol to analyze (e.g., 'VIC', 'VNM', 'VCB')", }, period: { type: "string", enum: ["1D", "1W", "1M"], description: "Time period for analysis: '1D' (daily), '1W' (weekly), '1M' (monthly). Default: '1D'", default: "1D", }, days: { type: "number", description: "Number of days to analyze (default: 30, max: 100). Used to detect Doji patterns in historical data.", default: 30, }, threshold: { type: "number", description: "Threshold for Doji detection as percentage of price range (default: 0.1 = 0.1%). Lower values detect more Doji patterns.", default: 0.1, }, }, required: ["symbol"], }, },
• src/index.ts:235-236 (registration)

  Handler registration in the switch statement for CallToolRequest.
  case "analyze_doji_pattern": return await this.analyzeDojiPattern(args as any);
• src/index.ts:1033-1151 (handler)

  Main handler function that orchestrates fetching historical stock data, detecting Doji patterns, classifying them, and generating analysis report.
  private async analyzeDojiPattern(args: { symbol: string; period?: "1D" | "1W" | "1M"; days?: number; threshold?: number; }) { const { symbol, period = "1D", days = 30, threshold = 0.1 } = args; const maxDays = Math.min(days, 100); const symbolUpper = symbol.trim().toUpperCase(); try { // Try to get OHLC data from FireAnt API let candles: any[] = []; try { // FireAnt API endpoint for historical data const apiUrl = `https://restv2.fireant.vn/symbols/${symbolUpper}/bars?resolution=${period}&from=${Date.now() - maxDays * 24 * 60 * 60 * 1000}&to=${Date.now()}`; const response = await fetch(apiUrl, { headers: { "User-Agent": "Mozilla/5.0", Accept: "application/json", }, }); if (response.ok) { const data: any = await response.json(); candles = Array.isArray(data) ? data : data.data || data.bars || []; } } catch (error) { // If API fails, provide guidance return { content: [ { type: "text", text: JSON.stringify( { symbol: symbolUpper, error: "Unable to fetch OHLC data from FireAnt API", note: "FireAnt API may require authentication. Please check FireAnt API documentation or use Firecrawl to scrape from https://www.fireant.vn", suggestion: "You can use Firecrawl MCP server to scrape historical price data from FireAnt website, then analyze Doji patterns manually.", dojiPatterns: this.getDojiPatternInfo(), }, null, 2 ), }, ], isError: true, }; } if (candles.length === 0) { return { content: [ { type: "text", text: JSON.stringify( { symbol: symbolUpper, error: "No price data available", note: "Unable to fetch historical price data. Please check if the symbol is correct or try using Firecrawl to scrape data.", dojiPatterns: this.getDojiPatternInfo(), }, null, 2 ), }, ], isError: true, }; } // Analyze Doji patterns const dojiPatterns = this.detectDojiPatterns(candles, threshold); const analysis = this.analyzeDojiSignificance(dojiPatterns, candles); return { content: [ { type: "text", text: JSON.stringify( { symbol: symbolUpper, period: period, analysisPeriod: `${maxDays} days`, totalCandles: candles.length, dojiPatternsFound: dojiPatterns.length, patterns: dojiPatterns, analysis: analysis, interpretation: this.getDojiInterpretation(dojiPatterns), note: "Doji patterns indicate market indecision. Always combine with other technical indicators for better trading decisions.", }, null, 2 ), }, ], }; } catch (error) { return { content: [ { type: "text", text: JSON.stringify( { error: error instanceof Error ? error.message : String(error), symbol: symbolUpper, note: "Unable to analyze Doji patterns. Please ensure you have access to price data.", dojiPatterns: this.getDojiPatternInfo(), }, null, 2 ), }, ], isError: true, }; } }
• src/index.ts:1153-1201 (helper)

  Helper function to detect Doji patterns in OHLC candle data.
  private detectDojiPatterns(candles: any[], threshold: number): any[] { const dojiPatterns: any[] = []; for (let i = 0; i < candles.length; i++) { const candle = candles[i]; const open = parseFloat(candle.open || candle.o || 0); const high = parseFloat(candle.high || candle.h || 0); const low = parseFloat(candle.low || candle.l || 0); const close = parseFloat(candle.close || candle.c || 0); const timestamp = candle.timestamp || candle.time || candle.date || i; if (open === 0 || high === 0 || low === 0 || close === 0) continue; const bodySize = Math.abs(close - open); const totalRange = high - low; const upperShadow = high - Math.max(open, close); const lowerShadow = Math.min(open, close) - low; // Threshold for Doji detection (body should be very small compared to range) const dojiThreshold = (totalRange * threshold) / 100; if (bodySize <= dojiThreshold && totalRange > 0) { const dojiType = this.classifyDojiType( bodySize, upperShadow, lowerShadow, totalRange ); dojiPatterns.push({ index: i, date: new Date(timestamp).toISOString(), open: open, high: high, low: low, close: close, bodySize: bodySize, totalRange: totalRange, upperShadow: upperShadow, lowerShadow: lowerShadow, type: dojiType.type, description: dojiType.description, significance: dojiType.significance, }); } } return dojiPatterns; }
• src/index.ts:1203-1279 (helper)

  Helper function to classify detected Doji patterns into specific types with descriptions and significance.
  private classifyDojiType( bodySize: number, upperShadow: number, lowerShadow: number, totalRange: number ): { type: string; description: string; significance: string } { const bodyRatio = bodySize / totalRange; const upperRatio = upperShadow / totalRange; const lowerRatio = lowerShadow / totalRange; // Four Price Doji: Open = High = Low = Close if (bodySize === 0 && totalRange === 0) { return { type: "Four Price Doji", description: "Extremely rare pattern where Open = High = Low = Close", significance: "Very strong indecision, extremely rare occurrence", }; } // Standard Doji: Small body with shadows on both sides if (bodyRatio < 0.1 && upperRatio > 0.2 && lowerRatio > 0.2) { return { type: "Standard Doji", description: "Open and close are nearly equal with shadows on both sides", significance: "Market indecision, potential trend reversal", }; } // Long-legged Doji: Small body with very long shadows if ( bodyRatio < 0.1 && upperRatio > 0.3 && lowerRatio > 0.3 && totalRange > 0 ) { return { type: "Long-legged Doji", description: "Small body with very long upper and lower shadows", significance: "High volatility and strong indecision, potential reversal", }; } // Dragonfly Doji: Small body at top, long lower shadow if ( bodyRatio < 0.1 && lowerRatio > 0.6 && upperRatio < 0.1 && totalRange > 0 ) { return { type: "Dragonfly Doji", description: "Open and close near the high, with long lower shadow", significance: "Bullish reversal signal, especially after downtrend", }; } // Gravestone Doji: Small body at bottom, long upper shadow if ( bodyRatio < 0.1 && upperRatio > 0.6 && lowerRatio < 0.1 && totalRange > 0 ) { return { type: "Gravestone Doji", description: "Open and close near the low, with long upper shadow", significance: "Bearish reversal signal, especially after uptrend", }; } // Generic Doji return { type: "Doji", description: "Open and close are nearly equal", significance: "Market indecision, watch for confirmation", }; }