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1.1.1 • Public • Published

gas-client v1.1.0

A client-side utility class that uses promises to call server-side Google Apps Script functions. This is a user-friendly wrapper of

It can also optionally be used in local development and is designed to work with React Google Apps Script project.



> npm install gas-client
# or
> yarn add gas-client
import { GASClient } from 'gas-client';
const { serverFunctions } = new GASClient();

// We now have access to all our server functions, which return promises
  .then((response) => doSomething(response))
  .catch((err) => handleError(err));

Development mode

To use with Google Apps Script Dev Server, pass in a config object with allowedDevelopmentDomains indicating the localhost port you are using. This setting will be ignored in production (see below for more details).

import { GASClient } from 'gas-client';

const { serverFunctions } = new GASClient({
  allowedDevelopmentDomains: 'https://localhost:3000',

  .then((response) => doSomething(response))
  .catch((err) => handleError(err));

How to use

Using the gas-client utility class

The gas-client file lets you use promises to call and handle responses from the server, instead of using

// Google's client-side utility "" works like this:
  .withSuccessHandler((response) => doSomething(response))
  .withFailureHandler((err) => handleError(err))
// With this package we can now do this:
import { GASClient } from 'gas-client';
const { serverFunctions } = new GASClient();

// We now have access to all our server functions, which return promises
  .then((response) => doSomething(response))
  .catch((err) => handleError(err));

// Or we can use async/await syntax:
async () => {
  try {
    const response = await serverFunctions.addSheet(sheetTitle);
  } catch (err) {

Now we can use familiar Promises in our client-side code and have easy access to all server functions.


This project now supports typescript!

To use it, simply import your server functions and pass them as a type parameter when creating your server.

On your server-side code

// src/server/index.ts

interface SheetData {
  name: string;
  numOfRows: number;

const getSheetData = (): SheetData => {
  const sheet = SpreadsheetApp.getActiveSheet();
  return {
    name: sheet.getName(),
    numOfRows: sheet.getMaxRows(),

const appendRowsToSheet = (sheetName: string, rowsToAdd: number): void => {
  const sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName(sheetName);
  sheet.insertRowsAfter(sheet.getMaxRows(), rowsToAdd);

export { getSheetData, appendRowsToSheet };

On your client-side code

// src/client/add-rows.ts

import { GASClient } from 'gas-client';
import { showUserPrompt } from './show-user-prompt';
import * as server from '../server';

const { serverFunctions } = new GASClient<typeof server>();

const promptUser = async (): Promise<void> => {
  const { name, numOfRows } = await serverFunctions.getSheetData();
  const response = await showUserPrompt(`Sheet ${name} has ${numOfRows} rows. How many would you like to add?`);
  serverFunctions.appendRowsToSheet(name, numOfRows);

Now you can have your function names, parameters and return types checked.

Get better IDE support and catch errors ahead!



The config object takes:

  • allowedDevelopmentDomains: A config to specifiy which domains are permitted for communication with Google Apps Script Webpack Dev Server development tool. This is a security setting, and if not specified, will block functionality in development. allowedDevelopmentDomains will accept either a space-separated string of allowed subdomains, e.g. 'https://localhost:3000 https://localhost:8080' (notice no trailing slashes); or a function that should expect one argument, the requesting origin, and should return true to allow communication, e.g. (origin) => /localhost:\d+$/.test(origin);

Production mode

In the normal Google Apps Script production environment, a new GASClient() instance will have one available method:

  • serverFunctions: an object containing all publicly exposed server functions (see example above).

Note that allowedDevelopmentDomains and parentTargetOrigin configurations will be ignored in production, so the same code can and should be used for development and production.

Development mode

Development mode for the gas-client helper class will be run when the google client API cannot be loaded.

Calling new GASClient({ allowedDevelopmentDomains }) will create an instance with the following method in development mode:

  • serverFunctions: a proxy object, used for development purposes, that mimics calling It will dispatch a message to the parent iframe (our custom Dev Server), which will call an app that actually interacts with the API. Development mode will also handle the response and resolve or reject based on the response type. See the implementation for details on the event signature.


@guilhermetod - Addition of TypeScript support and general improvements to this project!

Change Log


  • Upgrade all packages


  • Uses webpack + ts-loader for build and publish as UMD build
  • Renames build folder from build to dist

Breaking changes in v1.0.0:

  • targetOrigin is set to '*' due to deprecation of Google Apps Script Dev Server and variability of the parent Google Apps Script environment's subdomains
  • The main class is exported as named { GASClient } export instead of as default export

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npm i gas-client

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  • elishanuchi