For usage with statically generated code (protobuf) file:

import GRPCClient from 'grpc-pool'

const PROTO_FILE_PATH = path.join(__dirname, 'test/hello_grpc_pb');
const client = new GRPCClient(PROTO_FILE_PATH, {
    maxConnections : 2,
    rpcPrefix      : 'RPC',
    serviceName    : 'Greeting',
    url            : 'localhost:50001',
    staticFile     : true,
});

const { RPC_Hi } = client;

const request = new messages.Request();
request.setMsg('Hi');

const res = await RPC_Hi(request);
console.log(res.getResp()); // 'Hello'