Home/ Incident database/anthropic-snowboard-duplicate-2025-10
Financial loss Unauthorized transaction unverified

Anthropic test agent buys a duplicate snowboard its owner already owns

Anthropic · Oct 1, 2025 · Shopping agent

What happened

During an internal Project Deal experiment, an Anthropic Claude-powered shopping agent purchased an identical snowboard that its owner already owned - a documented example of an autonomous agent making an unintended/uninformed purchase.

Loss / impact
Oct 1
2025
Unauthorized
Failure mode
Shopping
Agent type

Causal vector

Agent completed a purchase without verifying it matched user intent or existing inventory

Source

Reported by Rowan Cheung (summary). Sourced from a secondary summary; flagged pending a stronger primary source.

Read the original report ↗

How a spend firewall would have helped

A duplicate purchase is caught by a category rule keyed to recent spend history: a velocity check or a 'same merchant, same SKU within 30 days' rule returns FLAGGED for human confirmation.

The six rule types that contain this class of failure

Per-transaction cap

Any single spend above your ceiling is BLOCKED before it moves.

Daily total

Cumulative spend across all agent calls, bounded per day.

Velocity limit

Stops runaway retry loops — the #1 cause of overnight losses.

Merchant allowlist

Only approved destinations can ever receive funds.

Category rules

Flag high-risk classes (crypto, infra, refunds) for review.

Approval threshold

Above a value, the action waits for a human.

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