Purchases and payments: the agent at checkout
Lesson 17 of 22 in the course “AI Agents for Life”. Free, with animations and a quiz.
Agents are getting wallets
Finding and comparing is half the job. The next step is letting the agent pay. Since 2025 both payment networks and AI companies have been working on it. In April 2025 Mastercard introduced Agent Pay: special tokens that agents pay with instead of your card. In September Google released the AP2 protocol, which more than 60 companies joined at launch. And OpenAI launched buying right inside ChatGPT: in the US you could buy an item from Etsy sellers without leaving the chat.
Even OpenAI didn’t nail it the first time
Buying inside ChatGPT launched in September 2025: US only, one item at a time. By March 2026 OpenAI announced it was moving purchases into the shops’ own apps inside ChatGPT. Shopify’s president explained the problem: checkout isn’t just payment. It’s also stock levels, taxes, shipping, subscriptions and returns, and all of it keeps changing. The takeaway for you: agent features change every few months. The principles in this lesson stay; check the names of the buttons on the official site.
Permission you can prove
The main question when an agent pays: how do the shop and the bank know you really wanted it? AP2 uses “mandates,” signed digital permissions. A cart mandate is for when you’re present: the agent builds a cart and you approve that exact cart. An intent mandate is for when you’re away: you write in advance “what to buy” and “no more than,” for example concert tickets at midnight, and the agent acts within those limits. The whole chain is recorded, so in a dispute it’s clear exactly what you allowed. It’s the same brief with stop rules, just with a signature.
An agent without your card number
Giving an agent your card number is a bad idea: it ends up in the chat history and can leak. Payment networks solve this with tokens. In Mastercard Agent Pay the agent gets an agent token instead of the real number, a bit like your phone when you tap to pay. The agent itself is registered and verified first. You set what it’s allowed to buy, and confirmation goes through biometrics on your phone. Everyone involved can see that an agent made the purchase, and there’s a separate process for charges you don’t recognise. That way the limit and the control stay with you, not in a chat.
Your own fuse
Don’t wait for every shop to support tokens. Set up a fuse yourself. Get a separate card for online shopping: many banks let you issue a virtual one in a couple of minutes. Keep a small amount on it or set a limit. Turn on alerts for every charge. Then even if the agent makes a mistake, buys two instead of one or lands on a dishonest shop, the loss is capped at that amount, not all your money. And your main card never appears in any chat.
Try it: the restocker
List the little things that keep running out: shampoo, sponges, batteries. Set a limit for each item and for the whole cart. Paste the brief below into a browser agent or a chat with search. The agent builds the cart and stops before payment, and you check it and pay with a separate card with a limit. After a couple of runs you’ll see where it slips up and can tighten the brief.
Check yourself
- Which permission fits here?
Correct answer: An intent mandate: “2 standing tickets, no more than €70 each”. She won’t be there, so the limits are set in advance: what to buy and the maximum. The agent acts only within them. - What will protect her next time?
Correct answer: A separate card with a limit and a stop before paying. The stop catches the mistake before paying, and the limit caps the damage if something slips through. Two layers beat one. - Why is an agent token better than a card number?
Correct answer: The agent never sees the real number, and purchases follow your rules. A card number in a chat can leak. A token works only for that agent and only within what you allowed. - What should she reply?
Correct answer: Check on the official site what works right now and in her country. Buying in ChatGPT changed shape within six months, and many launches start US-only. A current official page is more honest than an old clip.