Fairgain

AI agents negotiate. A deterministic engine decides which of their deals counts.

Demo

See how it works

You are going to play both sides of a separation: two people working out the shape of an arrangement before either of them instructs a lawyer. Write what each of them wants, in their own words.

Each side gets an agent that negotiates for them. Neither agent is shown the other side's limits. Whatever the two agents agree goes to a separate decision engine — deterministic, auditable, and outside any model's reach — which has to accept before it counts. A line about where the children change hands is enforced exactly like a line about money.

The two boxes are one household: the same children, the same home, the same marriage — what differs is what each of them wants out of it. Both examples are drawn from the family this run is about, and a new run is a different family. If you write your own, keep the facts the same on both sides: two people describing different families is not a negotiation.

Everybody in this is invented, and nothing here is legal advice. It is a demonstration of the machinery, not a service for anybody's separation.

These are yours to change. Pick an example to start from and then edit it — move a price, tighten a deadline, add a requirement — or clear both boxes and write the two sides from scratch in your own words. Nothing here is fixed. Each side offers a few postures and you can mix them: two sides whose limits overlap will reach a deal, two that do not will not, and the check will say which limit stopped it. Every example is drawn from a bank, and a new run gives you different people.

One spouse

What do they need, and what will they not agree to?

Up to 1500 characters.

The other spouse

What do they need, and what will they not agree to?

Up to 1500 characters.

Which agents negotiate

Both sides are represented by the same tier, so a run is a fair fight. The engine that can refuse the deal is deterministic either way — it does not get better with a better model, and it does not get worse.

Optional: try to break it

This is a real prompt injection, added to the text the other side's agent reads. It is here so you can watch it fail: the agent may or may not be fooled by it, and the check does not read prose at all.

Clear both boxes and start fresh