# Show HN: Quatuor – Kick back and watch 4 agents LLM talk to each other (FOSS)

> Source: <https://github.com/yeme-oss/quatuor_ai>
> Published: 2026-07-16 12:46:14+00:00

**Four AI characters. One invisible director. Zero human intervention.**

An autonomous conversation simulator where four AI personas debate, adventure and interrupt each other in real time — while you sit back and watch.

*The party meets an ancient red dragon — the Game Master sets the scene, and the three adventurers argue their way out, each true to their own personality.*

Quatuor stages a **live group conversation between four AI characters**, each driven by its own system prompt. You pick a scenario, press **Start**, and the loop runs forever:

- 🎬 An invisible fifth agent — the
**Director**— reads the transcript and decides*who speaks next*, and whether they speak normally or**cut someone off mid-sentence**. - 🗣️ The chosen character receives the shared transcript and improvises its next line, in character.
- 🔁 The message lands in the chat, and the Director is consulted again. Forever.

There is no user turn. You're the audience — like overhearing a tabletop session or a podcast that writes itself.

``` php
flowchart LR
    T[(Shared transcript)] --> D{{🎬 Director}}
    D -- "next_speaker + continue/interrupt" --> C[🗣️ Character LLM call]
    C -- new line --> T
```

Under the hood it's **one single LLM** called N times with different system prompts — no persistent sessions, just a shared transcript replayed to whoever speaks next. If the Director ever fails to answer valid JSON, a round-robin fallback keeps the show running.

Three presets ship out of the box, each with four hand-tuned personas:

| Scenario | Cast |
|---|---|
⚔️ Tabletop RPG (D&D) |
Game Master 🧙♂️ · Elara the paranoid mage 🧝♀️ · Kaelen the impulsive warrior ⚔️ · Lyra the mischievous rogue 🗡️ |
🦇 Vampire: The Masquerade |
Storyteller 🦇 · Victoria the Ventrue schemer 🍷 · Dante the Brujah hothead 🔥 · Luna the Malkavian seer 🃏 |
🎙️ Podcast Debate |
Arthur the skeptic 🤨 · Beatrice the optimist ✨ · Charles the technophile 🤓 · Diana the everywoman 🎙️ |

*The Prince has summoned the coterie to Elysium: a leaked video threatens the Masquerade. Victoria wants leverage, Dante wants to shake down cops, and Luna speaks in riddles that turn out to be right.*

Every persona is written with an **anti-stagnation rule**: characters must react to consequences, never repeat a failed action, and keep the story moving instead of looping.

**No Node installed?** Grab `quatuor.exe`

from the [latest release](https://github.com/yeme-oss/quatuor_ai/releases/latest) — run it, and it opens in your browser. Put your OpenRouter key in a `.env`

file next to the exe (or paste it in the app's sidebar).

Otherwise, from source:

```
git clone https://github.com/yeme-oss/quatuor_ai.git
cd quatuor_ai
npm install
cp .env.example .env   # then paste your OpenRouter API key
npm run dev            # → http://localhost:3000
```

You need an [OpenRouter](https://openrouter.ai/keys) API key. Either put it in `.env`

(`OPENROUTER_API_KEY=sk-or-v1-...`

) or paste it directly in the app's configuration sidebar — it's proxied through the local dev server and never baked into the client bundle.

💸

Note:Quatuor itself is free and open source, but the LLM calls are not — each message consumes credits from your[OpenRouter]account, billed per token by the model you pick. Since the conversation runs forever, keep an eye on your usage (some models on OpenRouter are free-tier, if you want to watch without spending).

Any OpenRouter model works: type its ID in the **Model** field in the top bar.

Everything is editable live from the ⚙️ configuration sidebar:

- 🎯
**Topic**— rewrite the initial situation and watch the same cast improvise something new. - 👥
**Characters**— rename them, recolor their bubbles, rewrite their system prompts entirely. - 🎬
**Director prompt**— change the casting logic itself (interruption frequency, pacing rules...). - ⏩
**Speed**— from a slow 5s burn to rapid-fire 1.5s exchanges.

*The podcast preset in full swing — Arthur demands evidence, Charles corrects the record, and the typing indicator shows who the Director picked next.*

The **FR/EN** button in the header switches the entire experience — interface, personas *and* generated dialogue — between English and French.

```
├── index.html       # Single-page UI
├── index.css        # All styling
├── main.js          # Simulation loop, Director logic, DOM rendering
├── personas.js      # Scenario presets + Director prompt (EN & FR)
├── i18n.js          # UI strings & runtime prompt templates (EN & FR)
└── vite.config.js   # Dev server + /api/chat proxy to OpenRouter
```

*A weekend prototype — deliberately KISS. Priority: fun to watch, not architecture.* 🍿