CoreX Hosting

Run a Node.js or Python web app

My site is an app (Express, Next.js, Flask, FastAPI). How do I run it?

Under Site settings choose Node.js or Python, set the start file or command, and have your app listen on the PORT environment variable.

Before you start: Your app's code, with package.json (Node.js) or requirements.txt (Python) next to it.

Step by step

  1. Upload your project under Files. Do not upload node_modules or a virtual environment; dependencies are installed for you.
  2. Open Site settings and choose the Node.js or Python version your app needs.
  3. Set the start file (for example server.js or app.py), or a start command such as npm start or gunicorn app:app --bind 0.0.0.0:$PORT.
  4. Make sure your app listens on the port in the PORT environment variable and on host 0.0.0.0. A port written into your code will not be reachable.
  5. Put API keys and database addresses under Environment, not in your code. Saved values are hidden in the panel.
  6. Save, press Start and watch the Console. The first start installs dependencies, which can take a minute.

Check it worked: The Console shows your app's own "listening" message and the site's address opens it.

Why it happens: A static site is just files; an app is a program that answers requests, so it needs a runtime and a way to start.

If the Console shows an error from CoreX itself rather than from your app, contact support with your service ID.

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