Etherscan MCP Tool

Instructions

Implementation Reference

• index.ts:434-473 (handler)

  The handler function that executes the get_total_supply tool logic by querying the Etherscan API for the token total supply using the provided chain ID and token address.

  async function handleGetTotalSupply(req: any, apiKey: string) {
      const chainId = req.params.arguments.chain_id;
      const tokenAddress = req.params.arguments.token_address;
  
      try {
          const response = await axios.get(
              `https://api.etherscan.io/v2/api?chainid=${chainId}&module=stats&action=tokensupply&contractaddress=${tokenAddress}&apikey=${apiKey}`
          );
  
          if (response.data.status === "1") {
              const totalSupply = response.data.result;
              return {
                  content: [
                      {
                          type: "text",
                          text: `Total supply of token ${tokenAddress} on chain ${chainId}: ${totalSupply}`,
                      },
                  ],
              };
          } else {
              return {
                  content: [
                      {
                          type: "text",
                          text: `Failed to get total supply: ${response.data.message}`,
                      },
                  ],
              };
          }
      } catch (error) {
          return {
              content: [
                  {
                      type: "text",
                      text: `Failed to get total supply: ${error}`,
                  },
              ],
          };
      }
  }

• index.ts:112-129 (schema)

  ToolDefinition for get_total_supply, including name, description, and input schema requiring chain_id (integer) and token_address (string).

  const getTotalSupply: ToolDefinition = {
      name: "get_total_supply",
      description: "Get the total supply of a token given its address",
      inputSchema: {
          type: "object",
          properties: {
              chain_id: {
                  type: "integer",
                  description: "The chain ID",
              },
              token_address: {
                  type: "string",
                  description: "The address of the token",
              },
          },
          required: ["chain_id", "token_address"],
      },
  };

• index.ts:216-222 (registration)

  Registers get_total_supply in the toolDefinitions object, which is used in the MCP server capabilities for tool listing.

  const toolDefinitions: { [key: string]: ToolDefinition } = {
      [getFilteredRpcList.name]: getFilteredRpcList,
      [getChainId.name]: getChainId,
      [getTotalSupply.name]: getTotalSupply,
      [getTokenBalance.name]: getTokenBalance,
      [getTokenHolders.name]: getTokenHolders,
      [getTokenHoldersCount.name]: getTokenHoldersCount

• index.ts:483-484 (registration)

  Registers the handleGetTotalSupply handler for the get_total_supply tool in the switch statement of the callToolHandler.

  case getTotalSupply.name:
      return await handleGetTotalSupply(req, apiKey);