EVM MCP Server

Instructions

Implementation Reference

• src/index.ts:162-190 (handler)

  The handler function that executes the eth_blockNumber tool. It makes an RPC call to get the latest block number in hex, parses it to decimal, adds a timestamp, and formats the response using formatResponse.

  async () => {
    try {
      const result = await makeRPCCall("eth_blockNumber");
      const blockNumber = parseInt(result, 16);
      return {
        content: [
          {
            type: "text",
            text: formatResponse(
              {
                hex: result,
                decimal: blockNumber,
                timestamp: new Date().toISOString(),
              },
              "Latest Block Number",
            ),
          },
        ],
      };
    } catch (error: any) {
      return {
        content: [
          {
            type: "text",
            text: `Error: ${error.message}`,
          },
        ],
      };
    }

• src/index.ts:161-161 (schema)

  Empty schema indicating no input parameters are required for the tool.

  {},

• src/index.ts:158-192 (registration)

  Registration of the eth_blockNumber tool using McpServer's server.tool method, specifying name, description, schema, and handler.

  server.tool(
    "eth_blockNumber",
    "Returns the number of the most recent block",
    {},
    async () => {
      try {
        const result = await makeRPCCall("eth_blockNumber");
        const blockNumber = parseInt(result, 16);
        return {
          content: [
            {
              type: "text",
              text: formatResponse(
                {
                  hex: result,
                  decimal: blockNumber,
                  timestamp: new Date().toISOString(),
                },
                "Latest Block Number",
              ),
            },
          ],
        };
      } catch (error: any) {
        return {
          content: [
            {
              type: "text",
              text: `Error: ${error.message}`,
            },
          ],
        };
      }
    },
  );

• src/index.ts:89-96 (helper)

  Helper function makeRPCCall used by the handler to send the RPC request to the Ethereum provider.

  async function makeRPCCall(method: string, params: any[] = []): Promise<any> {
    try {
      const result = await provider.send(method, params);
      return result;
    } catch (error: any) {
      throw new Error(`RPC call failed: ${error.message}`);
    }
  }