Who tests the agents that spend your money?

A while back I watched an AI agent complete a payment, never receive the HTTP response, and quietly retry — charging the customer twice. Nothing crashed. Every unit test was green. The logs said success.

That moment became Argus Agent Test Lab. We run adversarial black-box batteries against agents that move money — lost responses after payment, duplicate retries, timeouts, divergence between payment and execution — and seal every verdict in a public, hash-chained registry. A PASS is evidence you can verify, not a promise.

The self-service console is in open beta: 33 live engine runs free, no card. Claude Code connects with one command.

Now my question to this community: what's the strangest way you've seen an autonomous agent lose or double-spend money — unverified webhooks, retries without idempotency keys, a settled payment with no delivery? I'm collecting real failure stories, and the best ones become public test scenarios — with full credit to the author.