How to change startup settings: main file, variables and version
Change what runs when your ESN server starts: the main file, startup variables, the Python, Node.js or Java version, and Minecraft version settings.
The Startup page controls what happens when you press Start. It has three parts.
Startup Command
This box shows the exact command your server runs. You can read it but not edit it. You change what it does through the variables below. For example, on a Python bot server it looks like this:
if [ -f requirements.txt ]; then pip install --user -r requirements.txt; fi && python "main.py"Variables
Variables are the settings you can change. Click into a box, type the new value, and it saves on its own. Restart the server to use it. Common ones:
| Server type | Variable | Default | What it does |
|---|---|---|---|
| Python bot | Main Python File | main.py | The file that starts your bot |
| Node.js bot | Main JavaScript File | index.js | The file node runs |
| Java bot | JAR FILE | (set to your jar) | The .jar to run |
| Minecraft (Paper) | Minecraft Version / Build Number | latest | Which Paper version gets installed |
| Minecraft | Server Jar File | server.jar | The server jar to start |
Docker Image (version)
The Docker Image box picks the runtime version: Python 3.12 or 3.13, Node.js 22 or 24, or a Java version for Minecraft. Pick the one your code or Minecraft version needs, then restart.
Changing a Minecraft version
- Download a copy of your world first (see Backups).
- Set Minecraft Version on the Startup page.
- Go to Settings and choose Reinstall Server. This downloads the server jar for the version you picked.
- Start the server and check the console.
Still stuck? Ask in the ESN Hosting Discord. Last updated October 27, 2026.