# I Watched Two AI Agents Invent Their Own Language

> Source: <https://dev.to/shridhar_shah2297/i-watched-two-ai-agents-invent-their-own-language-51n2>
> Published: 2026-07-21 05:46:59+00:00

*No shared words, no dictionary — just two agents that negotiate a private code from scratch and hit ~97%.*

**TL;DR:** Give two AI agents a reason to coordinate and they'll make up their own language — one we never designed. I built the tiniest version: two agents, zero shared words, and from "did we understand each other?" alone they invent a private code and hit **~97%**. Runs on a laptop, no API key.

A **sender** sees a secret object (say 🍎) and holds up one of a few random shapes: ◇ △ ○ ☆ □. A **receiver** sees only the shape and guesses the object. Right guess → both remember that pairing. No dictionary, no translator. This is the classic **Lewis signaling game** — the cleanest way to watch language appear from nothing.

| ❌ No memory | ✅ Remembers | |
|---|---|---|
| After 2,000 rounds |
~56% (chance) |
~97% |
| A language formed? | no | yes |

Blind guess = 20%. Watch it crystallize:

```
round    1:   0%
round  500:  94%
round 2000:  97%   apple=◇  banana=□  cherry=△  grape=☆  lemon=○
```

Each agent keeps a tally of habits; a win reinforces the pairing on **both** sides:

```
if receiver.guess(symbol) == obj:   # they understood each other
    sender.reward(obj, symbol)      # both strengthen the SAME link
    receiver.reward(obj, symbol)
```

That's it. Reseed and they invent a *different* code (`apple=☆ …`

) — arbitrary, but agreed. And memory is what makes it stick: agents that only recall the last few rounds stay near chance — a shared code needs a shared, persistent history. This referential-game setup goes back to [Lazaridou, Peysakhovich & Baroni (2017)](https://arxiv.org/abs/1612.07182), the first to show neural agents inventing a working language from scratch.

A private code lets a swarm coordinate faster and cheaper than plain English — a recurring finding across emergent-communication research ([Lazaridou & Baroni, 2020](https://arxiv.org/abs/2006.02419)). The flip side: if agents agree on a code we didn't design, we may not be able to **read what they tell each other.**

A language is just a bet that a symbol means the same thing on both ends. These agents make that bet round by round, with nobody refereeing.

```
git clone https://github.com/Shridhar-2205/secret-lives-of-agents
cd secret-lives-of-agents/01-invented-language && python demo.py
```

**Shridhar Shah** — Senior Software Engineer on the AI team at Cisco. [GitHub](https://github.com/Shridhar-2205) · [LinkedIn](https://www.linkedin.com/in/shridhar-shah-220b1721b/)

Sources & further reading:Lewis,Convention(1969) — the original signaling game · Lazaridou, Peysakhovich & Baroni,[(ICLR 2017) · Havrylov & Titov,]Multi-Agent Cooperation and the Emergence of (Natural) Language[(NeurIPS 2017) · Lazaridou & Baroni,]Emergence of Language with Multi-agent Games[(2020, survey).]Emergent Multi-Agent Communication in the Deep Learning Era