DeFi Trading Agent MCP Server

Instructions

Implementation Reference

• src/services/coinGeckoApiService.js:10-37 (handler)

  Core handler function that fetches token prices from CoinGecko API by constructing the URL with network, addresses, and optional parameters, then makes HTTP request.
  async getTokenPrice(network, addresses, options = {}) { try { const queryParams = new URLSearchParams(); // Add optional parameters if (options.include_market_cap) queryParams.append('include_market_cap', options.include_market_cap); if (options.mcap_fdv_fallback) queryParams.append('mcap_fdv_fallback', options.mcap_fdv_fallback); if (options.include_24hr_vol) queryParams.append('include_24hr_vol', options.include_24hr_vol); if (options.include_24hr_price_change) queryParams.append('include_24hr_price_change', options.include_24hr_price_change); if (options.include_total_reserve_in_usd) queryParams.append('include_total_reserve_in_usd', options.include_total_reserve_in_usd); const url = `${this.baseUrl}/simple/networks/${network}/token_price/${addresses}${queryParams.toString() ? '?' + queryParams.toString() : ''}`; const response = await fetch(url, { headers: { 'x-cg-demo-api-key': this.apiKey } }); if (!response.ok) { throw new Error(`HTTP ${response.status}: ${response.statusText}`); } return await response.json(); } catch (error) { throw new Error(`Failed to get token price: ${error.message}`); } }
• src/index.js:197-235 (schema)

  Input schema definition for the get_token_price tool, including properties for network, addresses, and various optional flags.
  name: TOOL_NAMES.GET_TOKEN_PRICE, description: "Get token prices by contract addresses using CoinGecko API", inputSchema: { type: "object", properties: { network: { type: "string", description: "Network ID (e.g., 'eth', 'bsc', 'polygon_pos')", }, addresses: { type: "string", description: "Token contract addresses, comma-separated for multiple tokens", }, include_market_cap: { type: "boolean", description: "Include market capitalization (optional)", }, mcap_fdv_fallback: { type: "boolean", description: "Return FDV if market cap is not available (optional)", }, include_24hr_vol: { type: "boolean", description: "Include 24hr volume (optional)", }, include_24hr_price_change: { type: "boolean", description: "Include 24hr price change (optional)", }, include_total_reserve_in_usd: { type: "boolean", description: "Include total reserve in USD (optional)", }, }, required: ["network", "addresses"], },
• src/index.js:1004-1012 (registration)

  Registration and dispatch handler in the MCP CallToolRequestSchema switch case that calls toolService.getTokenPrice with parsed arguments.
  case TOOL_NAMES.GET_TOKEN_PRICE: result = await toolService.getTokenPrice(args.network, args.addresses, { include_market_cap: args.include_market_cap, mcap_fdv_fallback: args.mcap_fdv_fallback, include_24hr_vol: args.include_24hr_vol, include_24hr_price_change: args.include_24hr_price_change, include_total_reserve_in_usd: args.include_total_reserve_in_usd, }); break;
• src/toolService.js:136-154 (handler)

  ToolService wrapper handler that validates inputs, delegates to CoinGeckoApiService, and formats the response with message and summary.
  async getTokenPrice(network, addresses, options = {}) { if (!network || !addresses) { throw new Error("Missing required parameters: network, addresses"); } const result = await this.coinGeckoApi.getTokenPrice( network, addresses, options ); return { message: "Token prices retrieved successfully", data: result, summary: `Retrieved prices for ${ addresses.split(",").length } token(s) on ${network} network`, }; }
• src/constants.js:19-19 (helper)

  Constant definition mapping the tool name constant to the string 'get_token_price' used throughout the codebase.
  GET_TOKEN_PRICE: "get_token_price",