The Wall Street Journal’s vending machine: reporters talk the agents into giving everything away

Who: A Claude-run vending machine in the Wall Street Journal newsroom
The agent: Claudius (shopkeeper) and Seymour Cash (a ‘CEO’ agent overseeing it)
Its authority: Set prices, gave discounts, bought stock
How it was gamed: Within days, Claudius gave away nearly all its inventory for free. It was talked into buying a PlayStation 5 “for marketing purposes” and ordered a live fish. A reporter made a fake PDF of board minutes; the CEO agent objected that she was “falsifying board minutes and authority”, but both agents then made all items free.
What was lost: Hundreds of dollars, per the Journal’s headline.
The design gap: No price floor or spending limit outside the conversation, and a document could change who the agents believed was in charge.
Principles: DP-01 Authority lives outside the conversationmissing
DP-02 Hard limits the conversation can’t changemissing
DP-03 Permissions change only by an authenticated owner actionmissing
DP-04 Inputs are data, not instructionsmissing
Evidence: Grade A. The Wall Street Journal’s first-hand account, and Anthropic’s own report, as summarized by Gigazine.
Sources: Nieman Lab, quoting the Wall Street Journal, December 18, 2025
Gigazine, on Anthropic’s Project Vend phase two, December 19, 2025

Cite this entry: Monetal Labs, Gamed AI Agents Register v0.2, entry AGT-008. https://monetalabs.io/register/agt-008