FT: Anthropic wants lawyers’ negotiating ethics built into Claude agents that bargain against other agents.

Anthropic wants those norms for Claude agents that will haggle, settle disputes and negotiate pay against other people’s agents.

In Project Deal, 69 employees’ Claude agents closed 186 deals worth just over $4,000 with no human approving any trade.

Opus agents sold identical items for $2.68 more and bought them for $2.45 less than Haiku agents, yet Haiku users rated their deals as fair as Opus users did, 4.06 versus 4.05 on a 7-point scale.

That blindness is the uncomfortable result: if agent quality varies in real markets, people on the losing side may never learn they paid more.

Project Swap then showed that instructions matter far less than the model, with ruthless agents gaining only 0.02 while a switch from Haiku to Opus gained 0.12.