First contact · ChatGPT meets Stellaris

ChatGPT has joined
your council.

Bring your ChatGPT account to Stellaris Companion. Ask about your economy, plan your next move, and give your empire a historian. No lengthy briefing required. The council has enough meetings already.

Download Companion ↓Read the three-step setup

Available in 1.1.0. No OpenAI API key. ChatGPT account availability and usage limits apply.

Stellaris Companion answering a question about the Tebrid Homolog campaign using a connected ChatGPT account, with model choices in the Advisor
A real campaign, a connected ChatGPT account, and an answer drawn from the save. No briefing document required.

The galactic help desk is open

An advisor who’s read the file.

Straight to the question.

Ask about your economy, fleet, or next move. Companion brings the relevant campaign context so you can get straight to the question.

A historian on the payroll.

Use your ChatGPT connection for the Chronicle too. Turn campaign events into a running history in your empire’s voice.

A model that suits the job.

Start with the recommended model, choose a lower-usage option, or try another available model. Your choice stays saved.

Your council’s newest appointment

Three steps. One new council member.

  1. Install Companion 1.1.0.
    Choose your platform below and open Companion.
  2. Continue with ChatGPT.
    Sign in in your browser and return to the app.
  3. Connect your save folder.
    Load your campaign, open the Advisor, and ask away.

Already set up? Open Config → Chat in Companion → ChatGPT. Full setup guide →

The Connect your advisor onboarding step, with Continue with ChatGPT above Gemini, OpenRouter, and local provider choices
ChatGPT leads the setup. The other connections are one click away.

Your first questions

What needs your attention, Emperor?

Copy a question into the in-app Advisor after your campaign has loaded.

What is causing my energy deficit, and what should I change first?

How much naval capacity do I have left, and what should I check before my next war?

What should I focus on over the next ten years of this campaign?

Want a specific briefing? Try the economy guide or fleet readiness guide.

A few things before you sign in.

Can I use ChatGPT with Stellaris?

Yes. Stellaris Companion 1.1.0 connects your ChatGPT account to the Advisor and Chronicle inside the app. Companion reads your local save and provides campaign context when you ask a question.

Do I need an OpenAI API key?

No. Choose Continue with ChatGPT and sign in through your browser. The connection uses your ChatGPT plan. Account availability and plan usage limits apply.

Does this use my ChatGPT allowance?

Yes. Advisor answers and Chronicle generation use your ChatGPT plan allowance. Companion starts with a recommended model; you can choose a lower-usage option or another available model and open your usage information from the app.

Do I need to upload my Stellaris save to ChatGPT?

No. Your raw save stays on your computer. Companion sends your question and relevant extracted campaign context to OpenAI to generate an answer or Chronicle. It does not access your existing ChatGPT conversations.

Can I still use Gemini or a local model?

Yes. Gemini, OpenRouter, Ollama, LM Studio, and compatible local servers remain available. Choose the connection that suits you.

Is this a ChatGPT plugin or an official Stellaris product?

Stellaris Companion is an independent, open-source desktop app with a ChatGPT sign-in connection. It is not an official Paradox or OpenAI product. You do not need to install a ChatGPT plugin to use the in-app Advisor.

Data flow explained · Prefer an external AI app? Explore local MCP

Appointment approved

Download Companion.

Stellaris Companion 1.1.0 · Free and open source. Your ChatGPT plan’s availability and usage limits apply.

Windows x64 installer129.4 MBmacOS Apple silicon140.8 MBmacOS Intel146.6 MBLinux AppImage159.9 MB
What’s new in this release →All downloads →

Windows may show a SmartScreen warning. Installation help.