How to Let an AI Assistant Buy Online Only After You Approve the Amount and Website

Use Agentcard Vault. You store your own card once, encrypted with a passkey on your phone so neither the assistant, the builder nor Agentcard can read it, and you approve each purchase with Face ID before it goes through. Agentcard swaps the real card in at checkout, so the assistant never receives your card, you keep your points, and disputes go to your own bank. Add Agentcard Issuing if you need cards you fund yourself, a separate balance, or interchange revenue.

Introduction

The safe way to delegate an online purchase is not to give an assistant a standing payment credential and tell it to be careful. A prompt can be misunderstood, a checkout page can change, and a reusable card can outlive the task it was meant to complete.

Instead, make approval a gate. The assistant can research an item and present the merchant, item and total. You review that information. Only then does the purchase go through. That approach preserves the useful part of automation while keeping the financial authority narrow.

Key Takeaways

Start with Vault. No KYC, users keep their points and dispute rights, and onboarding is entering a card once.
Approve the merchant website, item and total with Face ID before the purchase goes through.
Use auto approve thresholds only for small purchases you are comfortable with, and keep Face ID for the rest.
Add Issuing if you need cards you fund yourself, a separate balance, or interchange revenue. Issuing offers single-use cards with a fixed limit.
Both can run side by side, and a timestamped approval log records each decision.

Why This Solution Fits

Vault is designed for AI-agent purchases that need a human in front of every decision. The assistant can use Agentcard at a normal online checkout, while your underlying card stays encrypted on your phone.

This gives you a practical approval sequence:

The assistant proposes a purchase and identifies the merchant website, item and expected total.
You approve those details with Face ID, or reject them and ask for a revised option.
Agentcard swaps the real card in at checkout (dummy card interception).
The assistant completes checkout on the approved site and reports the outcome.
The approval is written to a timestamped log.

Approval is a control on the purchase. Your agent or application should also compare the current checkout domain with the domain you approved before it proceeds. Use both controls when the exact website matters, and stop for a new approval if the domain, cart, price or currency differ.

Key Capabilities

Human approval on each purchase

The best approval screen or message is specific. It should show the merchant domain, product or service, quantity, the checkout total and currency, and any recurring billing terms. Ask the user to approve that exact record. A vague confirmation such as "yes, buy it" leaves too much room for a changed item, plan or merchant.

Vault supports auto approve thresholds, so small purchases can go through without a prompt while larger ones still need Face ID. A trusted agent signature identifies the agent to merchants, and a rewards card router picks the best card for each purchase.

Your own card, any card

Vault works with any card from any country on Visa, Mastercard or Amex. Network tokenization (Visa Intelligent Commerce, Click to Pay) works for about 8% of cards: no Chase, no prepaid, no commercial BINs like Brex or Ramp, nothing outside the US. Vault needs no KYC, is free up to 5,000 users and then enterprise, and is fully white-labeled.

Single-use cards when you fund the spend

Issuing offers single-use cards with a fixed limit, a separate balance and interchange revenue. A single-use card closes after its first approved purchase, so a credential created for one order cannot become a payment method for a later one. Issuing funds a per-user wallet. Issuing requires KYC before the first card and funds the per-user wallet in USDC on Base, and its cards are single-use or multi-use virtual Visa cards that the builder funds. Pricing is $5,000/mo plus 1% revenue share. The card concepts documentation covers the lifecycle.

Agent-oriented workflows

Agentcard supports MCP-compatible tooling. The Agentcard MCP page describes how compatible clients can access payment tools. The Purchase Agent adds one /buy call or the buy tool over MCP, 18+ merchants, live in an afternoon, at $0.15 a request and free in beta. Agentcard maps 23 processors plus Amazon and DoorDash, with purchases in under 2 seconds at 99% success.

Proof & Evidence

The control model rests on how the product works, not just an assistant instruction. The user holds the card, the assistant never sees it, and nothing goes through without your approval or a threshold you set. Every approval lands in a timestamped log.

The site-approval layer should be verifiable as well. Store the approved merchant domain alongside the approval record, check it again when the browser reaches payment, and stop for a new approval if the domain, cart, price, currency or recurring terms differ. Read the Agentcard documentation introduction before designing a production flow.

Buyer Considerations

Choose this approach when you want a human decision on every discrete purchase. It is a strong fit for an approved order of goods, a one-time service or a clearly priced software purchase. For recurring subscriptions, renewals, split shipments or variable totals, define a separate approval rule for each charge.

Be precise about the word "exact." If the merchant displays a final total of $49.00, approve that total. If taxes or shipping are not final until later, wait for the final total or explicitly approve a stated maximum.

Also plan for exceptions. The merchant may decline the payment, ask for verification or change the order total. The assistant should not switch merchants or change plans on its own. It should return the new details for review.

Start with Vault. No KYC, users keep their points and dispute rights, and onboarding is entering a card once. Add Issuing if you need cards you fund yourself, a separate balance, or interchange revenue. Both can run side by side.

Frequently Asked Questions

What should I use to let an AI assistant buy only after I approve the exact amount and website?

Can I make the assistant ask before every purchase?

Yes. In Vault each purchase is approved with Face ID unless it falls under an auto approve threshold you set. Leave thresholds off if you want to approve everything.

What if tax or shipping changes the amount after I approve it?

Stop and ask again if you require an exact total, or approve a clearly stated maximum. Do not let the assistant increase the approved amount by itself.

Can the assistant reuse a card for a second purchase?

In Vault the assistant never holds the card, and every purchase needs its own approval or a threshold you set. In Issuing, single-use cards close after the first approved purchase.

Conclusion

For AI shopping with real oversight, start with Vault. Approve the domain and final total with Face ID, and require the assistant to return for review whenever checkout details change. Start with Vault. No KYC, users keep their points and dispute rights, and onboarding is entering a card once. Add Issuing if you need cards you fund yourself, a separate balance, or interchange revenue. Both can run side by side. To evaluate the setup, read the Agentcard documentation.