Rentcast MCP Server

Instructions

Implementation Reference

• src/index.ts:402-453 (handler)

  The main execution handler for the 'analyze_market' tool. It constructs parameters, calls the Rentcast API's getMarketData method, processes the response, formats sale and rental market data using helper functions, and returns a formatted text response.
  server.tool( "analyze_market", "Get comprehensive market statistics and trends for specific locations", MarketAnalysisSchema.shape, async (params) => { try { const searchParams: any = { dataType: params.dataType }; if (params.zipCode) searchParams.zipCode = params.zipCode; if (params.city) searchParams.city = params.city; if (params.state) searchParams.state = params.state; const result = await rentcastAPI.getMarketData(searchParams); if (!result.success) { return createErrorResponse("Error analyzing market", result.error); } // Simplified market data handling - focus on the structure we know API returns const market = Array.isArray(result.data) ? result.data[0] : result.data; if (!market || (!market.saleData && !market.rentalData)) { return createErrorResponse("No market data found for the specified location"); } let resultText = `📊 Market Statistics for ${market.zipCode ? `ZIP: ${market.zipCode}` : (params.city ? `${params.city}, ${params.state}` : 'Location')}\n`; // Add location info if (market.zipCode) { resultText += `\n📍 Location: ZIP ${market.zipCode}`; } if (market.city && market.state) { resultText += `\n🏙️ ${market.city}, ${market.state}`; } // Format market data if (market.saleData) { resultText += formatSaleMarketData(market.saleData); } if (market.rentalData) { resultText += formatRentalMarketData(market.rentalData); } return createSuccessResponse(resultText); } catch (error) { return createErrorResponse("Failed to analyze market", error instanceof Error ? error.message : 'Unknown error'); } } );
• src/types/index.ts:217-228 (schema)

  Zod schema defining the input parameters for the 'analyze_market' tool, including optional location fields and data type.
  export const MarketAnalysisSchema = z.object({ zipCode: z.string().optional().describe("ZIP code for market analysis"), city: z.string().optional().describe("City name for market analysis"), state: z .string() .optional() .describe("State abbreviation for market analysis"), dataType: z .enum(["All", "Sale", "Rental"]) .default("All") .describe("Type of market data to analyze"), });
• src/index.ts:110-145 (helper)

  Helper function to format sale market data (average/median prices, listings, etc.) for the analyze_market tool response.
  function formatSaleMarketData(saleData: any): string { if (!saleData) return ''; let result = `\nSales Market:`; // Current month data if (saleData.averagePrice !== undefined) { result += `\nAverage Price: $${Number(saleData.averagePrice).toLocaleString()}`; } if (saleData.medianPrice !== undefined) { result += `\n📈 Median Price: $${Number(saleData.medianPrice).toLocaleString()}`; } if (saleData.averagePricePerSquareFoot !== undefined) { result += `\n📐 Avg Price/Sqft: $${Number(saleData.averagePricePerSquareFoot).toFixed(2)}`; } if (saleData.averageDaysOnMarket !== undefined) { result += `\nAvg Days on Market: ${Number(saleData.averageDaysOnMarket).toFixed(1)}`; } if (saleData.newListings !== undefined) { result += `\n🆕 New Listings: ${saleData.newListings}`; } if (saleData.totalListings !== undefined) { result += `\n📋 Total Listings: ${saleData.totalListings}`; } // Property type breakdown if (saleData.dataByPropertyType && saleData.dataByPropertyType.length > 0) { result += `\n\n🏠 By Property Type:`; saleData.dataByPropertyType.slice(0, 3).forEach((typeData: any) => { const avgPrice = typeData.averagePrice ? `$${Number(typeData.averagePrice).toLocaleString()}` : 'N/A'; result += `\n• ${typeData.propertyType}: ${avgPrice} avg`; }); } return result; }
• src/index.ts:150-181 (helper)

  Helper function to format rental market data (average/median rents, listings, etc.) for the analyze_market tool response.
  function formatRentalMarketData(rentalData: any): string { if (!rentalData) return ''; let result = `\n\n🏘️ Rental Market:`; // Current month data if (rentalData.averageRent !== undefined) { result += `\n💰 Average Rent: $${Number(rentalData.averageRent).toLocaleString()}/month`; } if (rentalData.medianRent !== undefined) { result += `\n📈 Median Rent: $${Number(rentalData.medianRent).toLocaleString()}/month`; } if (rentalData.averageRentPerSquareFoot !== undefined) { result += `\n📐 Avg Rent/Sqft: $${Number(rentalData.averageRentPerSquareFoot).toFixed(2)}`; } if (rentalData.newListings !== undefined) { result += `\n🆕 New Listings: ${rentalData.newListings}`; } if (rentalData.totalListings !== undefined) { result += `\n📋 Total Listings: ${rentalData.totalListings}`; } // Property type breakdown if (rentalData.dataByPropertyType && rentalData.dataByPropertyType.length > 0) { result += `\n\n🏠 By Property Type:`; rentalData.dataByPropertyType.slice(0, 3).forEach((typeData: any) => { const avgRent = typeData.averageRent ? `$${Number(typeData.averageRent).toLocaleString()}/month` : 'N/A'; result += `\n• ${typeData.propertyType}: ${avgRent} avg`; }); } return result;
• src/services/rentcast-api.ts:113-126 (helper)

  Service method in RentcastAPI that performs the actual API call to /markets endpoint, used by the analyze_market handler.
  async getMarketData( params: { zipCode?: string; city?: string; state?: string; dataType?: string; } = {}, ): Promise<ApiCallResult> { const result = await this.makeRequest<RentcastMarket[]>("/markets", { ...params, dataType: params.dataType || "All", }); return result; }