MCP Etherscan Server

Instructions

Implementation Reference

• src/server.ts:285-299 (handler)

  Executes the get-gas-prices tool by calling EtherscanService.getGasOracle(), formatting the safe, standard, and fast gas prices into a text response.

  if (name === "get-gas-prices") {
    try {
      const prices = await etherscanService.getGasOracle();
      const response =
        `Current Gas Prices:\n` +
        `Safe Low: ${prices.safeGwei} Gwei\n` +
        `Standard: ${prices.proposeGwei} Gwei\n` +
        `Fast: ${prices.fastGwei} Gwei`;
      return {
        content: [{ type: "text", text: response }],
      };
    } catch (error) {
      throw error;
    }
  }

• src/server.ts:138-146 (schema)

  Defines the tool schema with name, description, and empty input schema (no parameters required).

  {
    name: "get-gas-prices",
    description: "Get current gas prices in Gwei",
    inputSchema: {
      type: "object",
      properties: {},
    },
  },
  {

• src/server.ts:63-163 (registration)

  Registers the get-gas-prices tool in the list of available tools returned by ListToolsRequestHandler.

  server.setRequestHandler(ListToolsRequestSchema, async () => {
    return {
      tools: [
        {
          name: "check-balance",
          description: "Check the ETH balance of an Ethereum address",
          inputSchema: {
            type: "object",
            properties: {
              address: {
                type: "string",
                description: "Ethereum address (0x format)",
                pattern: "^0x[a-fA-F0-9]{40}$",
              },
            },
            required: ["address"],
          },
        },
        {
          name: "get-transactions",
          description: "Get recent transactions for an Ethereum address",
          inputSchema: {
            type: "object",
            properties: {
              address: {
                type: "string",
                description: "Ethereum address (0x format)",
                pattern: "^0x[a-fA-F0-9]{40}$",
              },
              limit: {
                type: "number",
                description: "Number of transactions to return (max 100)",
                minimum: 1,
                maximum: 100,
              },
            },
            required: ["address"],
          },
        },
        {
          name: "get-token-transfers",
          description: "Get ERC20 token transfers for an Ethereum address",
          inputSchema: {
            type: "object",
            properties: {
              address: {
                type: "string",
                description: "Ethereum address (0x format)",
                pattern: "^0x[a-fA-F0-9]{40}$",
              },
              limit: {
                type: "number",
                description: "Number of transfers to return (max 100)",
                minimum: 1,
                maximum: 100,
              },
            },
            required: ["address"],
          },
        },
        {
          name: "get-contract-abi",
          description: "Get the ABI for a smart contract",
          inputSchema: {
            type: "object",
            properties: {
              address: {
                type: "string",
                description: "Contract address (0x format)",
                pattern: "^0x[a-fA-F0-9]{40}$",
              },
            },
            required: ["address"],
          },
        },
        {
          name: "get-gas-prices",
          description: "Get current gas prices in Gwei",
          inputSchema: {
            type: "object",
            properties: {},
          },
        },
        {
          name: "get-ens-name",
          description: "Get the ENS name for an Ethereum address",
          inputSchema: {
            type: "object",
            properties: {
              address: {
                type: "string",
                description: "Ethereum address (0x format)",
                pattern: "^0x[a-fA-F0-9]{40}$",
              },
            },
            required: ["address"],
          },
        },
      ],
    };
  });

• src/services/etherscanService.ts:155-179 (helper)

  Core helper function that fetches current gas oracle data from Etherscan API and parses safeGasPrice, ProposeGasPrice, and FastGasPrice.

  async getGasOracle(): Promise<GasPrice> {
    try {
      // Get current gas prices
      const result = await fetch(
        `https://api.etherscan.io/api?module=gastracker&action=gasoracle&apikey=${this.provider.apiKey}`
      );
      
      const data = await result.json();
      
      if (data.status !== "1" || !data.result) {
        throw new Error(data.message || "Failed to fetch gas prices");
      }
  
      return {
        safeGwei: data.result.SafeGasPrice,
        proposeGwei: data.result.ProposeGasPrice,
        fastGwei: data.result.FastGasPrice
      };
    } catch (error) {
      if (error instanceof Error) {
        throw new Error(`Failed to get gas prices: ${error.message}`);
      }
      throw error;
    }
  }