Deploy Your First App — Complete Walkthrough

This walkthrough takes you from an empty folder on your computer to a live website on the Domain India App Platform. You'll write a tiny Node.js app, test it locally, and deploy it with a deploy token. No previous deployment experience is needed, and you don't need Git, Docker or an SSH key.

1. What you need

On Windows, use PowerShell, not the old Command Prompt.

This guide uses Node.js because Node.js apps are detected and built automatically. Python, PHP and other languages also run on the platform, but they need a Dockerfile in your project; the getting-started guide has a minimal Python example.

2. Create the project

mkdir hello-app
cd hello-app

Create three files in that folder.

index.js, the application:

const http = require('http');

// The platform tells your app which port to use.
// On your computer there is no PORT, so fall back to 3000.
const port = process.env.PORT || 3000;

const server = http.createServer((req, res) => {
  res.writeHead(200, { 'Content-Type': 'text/html; charset=utf-8' });
  res.end('<h1>Hello from App Platform</h1><p>My first deployment.</p>');
});

// 0.0.0.0 accepts connections from outside the container.
server.listen(port, '0.0.0.0', () => {
  console.log(`Listening on port ${port}`);
});

package.json, which tells the platform this is a Node.js project:

{
  "name": "hello-app",
  "version": "1.0.0",
  "private": true,
  "scripts": {
    "start": "node index.js"
  }
}

Procfile, with no file extension, which says how to start the app:

web: node index.js

That's the whole application, with no dependencies to install.

3. The two rules that decide whether your app works

Almost every "the build succeeded but my site doesn't load" problem comes down to one of these:

1. Listen on the port in PORT. Never hard-code a port number.
2. Bind to 0.0.0.0, not localhost. An app bound to localhost only accepts connections from inside its own container, so visitors see nothing.

server.listen(3000, 'localhost');             // wrong: unreachable
server.listen(process.env.PORT, '0.0.0.0');   // right

4. Run it on your computer first

If it doesn't run locally, it won't run on the platform either.

PORT=3000 node index.js

On Windows PowerShell:

$env:PORT=3000; node index.js

You should see Listening on port 3000. Open http://localhost:3000 in your browser and you should see "Hello from App Platform". Stop the server with Ctrl+C.

5. Create the app and a deploy token

6. Package and deploy

Move up one level, to the folder that contains hello-app, and package it:

cd ..
tar czf app.tar.gz --exclude=node_modules --exclude=.git -C hello-app .

-C hello-app . packages the contents of hello-app, not the folder itself. That matters: the platform expects package.json at the top of the archive.

Now paste and run the command you copied from the Deploy Tokens tab, in the same folder as app.tar.gz. Don't type the command by hand; copying it avoids a wrong address or a leftover placeholder.

The command waits while your app builds, then prints the result. Behind the scenes:

1. Your archive is received.
2. The platform finds package.json and treats the project as Node.js.
3. Dependencies are installed and the app is built.
4. A health check runs on the new version.
5. Traffic switches to it with no downtime.

You can follow the same build output in the Deploys tab.

7. Open your live site

Go to the app's Overview tab and open its address. You should see "Hello from App Platform", served over HTTPS.

8. Change something and deploy again

Edit the message in index.js:

res.end('<h1>Hello from App Platform</h1><p>Updated!</p>');

Then repeat step 6: package, then run the same upload command. Refresh your site and the change is live. This is the loop you'll use from now on.

9. If something goes wrong

More fixes are in Troubleshooting the App Platform.

10. Next steps

• Settings and secrets: Environment variables
• A database: PostgreSQL database
• Your own domain: Custom domains and SSL
• Deploy from GitHub: Deploying from GitHub

Ready to go live? Open your App Platform apps, compare App Platform plans, or ask us in a support ticket.