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",