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), 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). 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 · LinkedIn
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