Server-Side Apps Are Here: Deploy Python & Node.js on gapp.so

Your AI-Built Apps Can Now Have a Backend

Until now, apps published on gapp.so ran entirely in the browser — great for tools, games, and visualizations, but limiting if your app needs server-side logic.

Now, gapp.so supports full server-side applications. Python and Node.js apps that need a real backend can be published with the same workflow you already know.

Nothing Changes for You

The way you build and publish apps is exactly the same:

1. Build your app with your favorite AI tool — Gemini in AI Studio, Claude Code, Cursor, or anything else
2. Upload the code to gapp.so (via the submit page, or the Publish API)
3. Done — your app is live with a landing page, a shareable URL, and SEO

The only difference is what your app can do. Before, your app ran in the browser. Now, it can also run on a server — meaning it can handle API requests, process data, connect to databases, and more.

You don't need to know the difference. If your AI assistant generates a Flask or Express app, gapp.so detects it automatically and deploys it to a server for you. If it generates a static HTML or React app, it works the same as before.

What This Means

Here are some things you can now ask your AI assistant to build:

• API backends — "Build me a REST API that stores and retrieves todo items"
• Data processing tools — "Create a web app that converts CSV files to JSON"
• Real-time dashboards — "Make a dashboard that shows live server metrics"
• AI-powered services — "Build a text summarizer API using Python"

Your AI assistant will generate the server code. You upload it. gapp.so handles the rest.

Supported Technologies

Managing Your Server App

Server apps get an extra Server tab in your dashboard where you can:

• Check if your app is running or stopped
• Restart your server with one click
• View logs for debugging

Server apps automatically pause when nobody is using them and restart when someone visits — so you don't pay for idle time.

Technical Details (Optional Reading) {#technical-details}

> *The section below is for developers who want to understand the internals. Most users can skip this entirely.*

Auto-Detection

When you upload files, gapp.so scans your project to determine deployment type:

• Node.js: Looks for package.json with server framework dependencies (express, fastify, hono, koa, @nestjs/core, etc.)
• Python: Looks for requirements.txt or pyproject.toml with server framework dependencies (flask, fastapi, django, etc.)

If server dependencies are found, the app is deployed to a dedicated Fly.io machine. Otherwise, it's deployed as a static site via Cloudflare R2.

Dependency Installation

• Node.js: Runs npm install from package.json
• Python (pip): Runs pip install -r requirements.txt
• Python (uv): Runs uv sync from pyproject.toml + uv.lock (falls back to non-frozen if lock file is stale)

Start Command Detection

gapp.so automatically determines how to start your app:

• Node.js: Uses scripts.start from package.json, or falls back to node {entry file}
• Python: Detects the framework and generates the appropriate command (e.g., gunicorn app:app, uvicorn main:app --host 0.0.0.0)

Infrastructure

• Apps run on Fly.io Machines in the NRT (Tokyo) region
• Pre-built runner images for Node.js and Python (no Docker build step for users)
• Auto-stop after idle, auto-start on request (scale-to-zero)
• Each app gets a dedicated machine with its own public URL

Environment Variables

If your server app needs secrets (API keys, database URLs, etc.), you can add encrypted environment variables from the dashboard's Server tab. Values are encrypted at rest and injected into your app's runtime on deploy.

Ready to try it? Publish your app — the same way you always have.