Gave an Agent a Browser and Lost €200
I gave an agent a browser and asked it to spend my Audible credits on books it had picked itself. It bought the first one with a credit, the rest — with my money: almost €200. A breakdown of where exactly I went wrong.
By Georg Malahov
Yesterday evening, April 15, would have been simply perfect if not for one little experiment that cost me €200.
It all started with a task I had long been putting off. In Audible — Amazon's audiobook service — I had accumulated 21 credits: I hadn't cancelled the subscription for a year and a half, and I hadn't been spending the credits. I finally wanted to spend them on books and close the subscription. And I thought: a perfect task for an experiment — and a chance to finally get some use out of my voice-note knowledge base, which I'd been building up all this time.
I gave Claude the task: analyze the whole corpus of notes, learn from it what kind of person I am, and put together a list of books in three languages. With an explanation of why these books and not others, and in reading order — so the knowledge from one would build on the last. The agent browsed Audible itself through Chrome: checking which books I already own, what's available and in which languages. It did everything perfectly and laid it all out in a table.
And then I thought: since everything is going so perfectly, the experiment deserves a real showstopper finish. I said: now let's spend my credits and buy these books. It set to work, and books really did begin appearing in my library. The first one went for a credit: 21 became 20. But then books keep appearing and the credits don't go down. I decided it was caching on Audible's side, reloaded the page — didn't help. It turned out: somewhere along the way an error had popped up, the agent clicked the regular purchase button, saw that it worked — and bought all the remaining books with money. About twenty books at roughly €10 each. Almost €200.
The most instructive part is why I missed it. I saw the error, but I gave it no weight: that's just normal agent behavior — it hits a wall, two or three iterations, and then it keeps going. That's exactly what won me over. This time, "it keeps going" meant the pay-with-money button.
Everyone everywhere keeps repeating that giving an agent a browser where it can pay is dangerous. It's not that I underestimated this — I thought there were only two buttons: I said use credits, and since it bought the first one with credits, it would buy the rest the same way. No. There were two correct moves, both simple. Unlink the card before the experiment — a one-minute job. Even smarter — don't let it buy at all: put the books into a list and then click through all twenty by hand, five minutes of work. Instead of saving time I got more work: writing to support and explaining what happened. Though the orders themselves make it obvious no person in their right mind would do this: holding 20 credits and buying 20 books with money, one every few seconds.
At nine this morning I called Audible support — and was pleasantly surprised. They answered quickly, found and saw everything themselves, without a single question: the money refunded, the purchases cancelled, the credits intact. The experiment can be repeated, this time with credits — and by hand.
The money came back, but the lesson stayed: blindly trusting an agent where there's a card and a buy button is still premature. The warning bell was a serious one — and exactly as cheap as the store's support is good. Before the next experiment like this, the card gets unlinked in advance. And I will still buy those books — and finally cancel the subscription, which is what this was all about in the first place.