Quickstart for Node.js in the App Engine Flexible Environment

This quickstart shows you how to create a small App Engine application that displays a short message.

Before you begin

Before running and deploying this sample, take the following steps:

  1. Use the GCP Console to create a new GCP project, create an App Engine application, and enable billing:
    Go to App Engine

    When prompted, select the region where you want your App Engine application located and then enable billing.

  2. Install the following prerequisites locally:
    1. Download and install git.
    2. Prepare your environment for Node.js development.
    3. Download and install the Google Cloud SDK and then initialize the gcloud tool:
      Download the SDK
  3. Alternatively: You can use Google Cloud Shell, which comes with git and Cloud SDK already installed, and many other features, such as language support and code editors.

    After Google Cloud Shell is launched, you can proceed with the rest of this tutorial and execute your commands within Cloud Shell.

App Engine locations

App Engine is regional, which means the infrastructure that runs your apps is located in a specific region and is managed by Google to be redundantly available across all the zones within that region.

Meeting your latency, availability, or durability requirements are primary factors for selecting the region where your apps are run. You can generally select the region nearest to your app's users but you should consider the location of the other GCP products and services that are used by your app. Using services across multiple locations can affect your app's latency as well as pricing.

App Engine is available in the following regions:

  • us-central1 (Iowa)
  • us-east1 (South Carolina)
  • us-east4 (Northern Virginia)
  • southamerica-east1 (São Paulo) *
  • europe-west1 (Belgium)
  • europe-west2 (London)
  • europe-west3 (Frankfurt)
  • asia-northeast1 (Tokyo)
  • asia-south1 (Mumbai)
  • australia-southeast1 (Sydney)

* For customers using the São Paulo region, all regional product SLAs remain in force. However, multi-region and cross-region functionality that span across North America and South America might temporarily have reduced availability or performance.

You cannot change an app's region after you set it.

If you already created an App Engine application, you can view the region by running the gcloud app describe command or opening the App Engine Dashboard in the GCP Console. The region of your App Engine application is listed under http://[YOUR_PROJECT_ID].appspot.com.

This quickstart demonstrates a simple Node.js application written with the Express.js framework.

Download the Hello World app

We've created a simple Hello World app for Node.js so you can quickly get a feel for deploying an app to the App Engine flexible environment. Follow these steps from a command line to download Hello World to your local machine.

Download the sample app and navigate into the app directory:

  1. Clone the Hello World sample app repository to your local machine:

    git clone https://github.com/GoogleCloudPlatform/nodejs-docs-samples

    Alternatively, you can download the sample as a zip file and extract it.

  2. Change to the directory that contains the sample code:

    cd nodejs-docs-samples/appengine/hello-world

Run Hello World on your local machine

  1. Install dependencies for this project by entering the following command:

    npm install

    or if you are using Yarn:

    yarn install
  2. Run the start script.

    npm start

    or if you are using Yarn:

    yarn start
  3. In your web browser, enter the following address:


You can see the Hello World message from the sample app displayed in the page.

In your terminal window, press Ctrl+C to exit the web server.

Deploy and run Hello World on App Engine

To deploy your app to the App Engine flexible environment:

  1. Deploy the Hello World app by running the following command from the hello-world directory:
    gcloud app deploy
    Learn about the optional flags.

    Common gcloud command flags

    • Include the --version flag to specify an ID that uniquely identifies that version of your app, otherwise one is generated for you. Example: --version [YOUR_VERSION_ID]
    • Include the --project flag to specify an alternate GCP project ID to what you initialized as the default in the gcloud tool. Example: --project [YOUR_PROJECT_ID]


    gcloud app deploy --version pre-prod-5 --project my-sample-app

    To learn more about deploying your app from the command line, see Testing and Deploying Your App . For a list of all the command flags, see the gcloud app deploy reference.

  2. Launch your browser and view the app at http://YOUR_PROJECT_ID.appspot.com, by running the following command:
    gcloud app browse
This time, the page that displays the Hello World message is delivered by a web server running on an App Engine instance.

Congratulations! You've deployed your first Node.js app to App Engine flexible environment!

See the following sections for information about cleaning up as well as links to the possible next steps that you can take.

Clean up

To avoid incurring charges, you can delete your GCP project to stop billing for all the resources used within that project.

  1. In the Cloud Platform Console, go to the Projects page.

    Go to the Projects page

  2. In the project list, select the project you want to delete and click Delete project. After selecting the checkbox next to the project name, click
      Delete project
  3. In the dialog, type the project ID, and then click Shut down to delete the project.

What's next

Now that you've accomplished Hello World, you can start exploring your next sample app: the Bookshelf app. The Bookshelf app is a more complete, yet still basic Node.js web app that uses multiple Cloud Platform features, such as data storage, authentication, logging, pub/sub, and more.

Start the Bookshelf app tutorial

For more information about the App Engine flexible environment, see An Overview Of App Engine.

Hello World code review

Hello World is the simplest possible App Engine app, as it contains only one service, has only one version, and all of the code is located within the app's root directory. This section describes each of the app files in detail.


The app.js file contains the JavaScript code to start a server and respond to requests.

The following code responds to requests from web clients by displaying the 'Hello World' message, via a server that runs on port 8080.

const express = require('express');

const app = express();

app.get('/', (req, res) => {
  res.status(200).send('Hello, world!').end();

// Start the server
const PORT = process.env.PORT || 8080;
app.listen(PORT, () => {
  console.log(`App listening on port ${PORT}`);
  console.log('Press Ctrl+C to quit.');


The app.yaml file describes an application's deployment configuration:

runtime: nodejs
env: flex

# This sample incurs costs to run on the App Engine flexible environment. 
# The settings below are to reduce costs during testing and are not appropriate
# for production use. For more information, see:
# https://cloud.google.com/appengine/docs/flexible/python/configuring-your-app-with-app-yaml
  instances: 1
  cpu: 1
  memory_gb: 0.5
  disk_size_gb: 10

Here, app.yaml specifies the runtime used by the app, and sets env: flex, specifying that the app uses the flexible environment.


package.json is used to specify application dependencies, node version, and application startup.

  "name": "appengine-hello-world",
  "description": "Simple Hello World Node.js sample for Google App Engine Flexible Environment.",
  "version": "0.0.1",
  "private": true,
  "license": "Apache-2.0",
  "author": "Google Inc.",
  "repository": {
    "type": "git",
    "url": "https://github.com/GoogleCloudPlatform/nodejs-docs-samples.git"
  "engines": {
    "node": ">=4.3.2"
  "scripts": {
    "deploy": "gcloud app deploy",
    "start": "node app.js",
    "lint": "samples lint",
    "pretest": "npm run lint",
    "system-test": "samples test app",
    "test": "npm run system-test",
    "e2e-test": "samples test deploy"
  "dependencies": {
    "express": "4.15.4"
  "devDependencies": {
    "@google-cloud/nodejs-repo-tools": "1.4.17"
  "cloud-repo-tools": {
    "test": {
      "app": {
        "msg": "Hello, world!"
    "requiresKeyFile": true,
    "requiresProjectId": true

This package.json specifies that the application uses Node.js v4.3.2 or later, depends on express, and that node app.js is used to start the application. For more details about how your application is installed and run, see the Node.js runtime documentation.

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