A Safer Way to Isolate Every AI Purchase: Vault First, Single-Use Cards Second

For AI-agent purchases where each one should be isolated from your everyday credentials, start with Agentcard Vault. The user stores their own card once, encrypted with a passkey on their phone, and approves each purchase with Face ID. Agentcard swaps the real card in at checkout, so the agent never holds a card number, and every approval is written to a timestamped log. If you specifically need a new single-use card for every transaction that you fund yourself, add Agentcard Issuing, which offers single-use cards and a separate balance. Both can run side by side.

Introduction

A reusable card is a poor permission model for autonomous purchasing. It can be copied into an agent session, browser state, tool output or a merchant account. It may also remain available after the original task has finished. A spending instruction in a prompt is not a payment control when the credential itself can be reused.

The better question is how each purchase gets isolated. There are two good answers. In Vault, the agent never holds the card and each purchase needs an approval or falls under a threshold the user set. In Issuing, a builder-funded single-use card is good for one purchase. The Agentcard introduction describes both product paths.

This matters for people delegating routine purchases and for teams building agents that buy goods, services, software or data online.

Key Takeaways

Start with Vault. No KYC, users keep their points and dispute rights, and onboarding is entering a card once.
In Vault the agent never holds the real card, and every purchase is approved with Face ID or an auto approve threshold, then logged with a timestamp.
Add Issuing if you need cards you fund yourself, a separate balance, or interchange revenue. Issuing offers single-use cards that close after their first approved purchase.
Both can run side by side. Agentcard supports agent workflows through MCP, CLI and API.

Decision criteria

1. Who holds the card

Isolation starts with where the real credential lives. With Vault it lives on the user's phone, encrypted with a passkey so neither the agent, the builder nor Agentcard can read it. With Issuing, the builder funds and holds a card program.

2. A control that is not just a prompt

Look for controls that are enforced outside the agent. In Vault, each purchase needs a Face ID approval unless it falls under an auto approve threshold, and a trusted agent signature identifies the agent to merchants. In Issuing, a single-use card has a fixed limit and is good for one purchase.

3. Separation from the reusable credential

The central security benefit is credential separation. In Vault the agent never receives the user's card details, because Agentcard swaps the real card in at checkout (dummy card interception). The user also keeps their credit card points, and disputes go to their own bank. This does not remove every operational risk, such as selecting the wrong item, which is why approvals matter.

4. Checkout compatibility for the work you need done

A control is only helpful if the agent can complete the intended purchase. 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. Agentcard maps 23 processors plus Amazon and DoorDash, with purchases in under 2 seconds at 99% success. Test your merchant and purchase type before relying on automation.

5. Human oversight and programmatic control

Decide where approval belongs. A personal user may want to approve each purchase with Face ID. A platform may want auto approve thresholds for small purchases and a timestamped approval log for review. Vault is fully white-labeled, free up to 5,000 users and then enterprise, so a platform can offer it inside its own product.

How to choose

If you want an AI assistant to make purchases without seeing your everyday card, choose Vault. Store the card once and approve each purchase. Auto approve thresholds keep small purchases frictionless.

If you are building an agent that must buy from normal online merchants, start with Vault. The real card is swapped in at the merchant checkout, and the MCP offering is designed for compatible agent environments.

If you want a new single-use card for every purchase that you fund yourself, add Issuing. Issuing offers a separate balance, interchange revenue and single-use cards, and it funds a per-user wallet. Issuing requires KYC before the first card, 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. See the card concepts documentation for the card lifecycle.

If each purchase has a known maximum, set it as a threshold in Vault or as the limit on an Issuing card. The goal is a purchase scoped to an individual approval, not a general-purpose balance.

If a purchase needs a recurring billing relationship, do not assume a single-use card is the right mechanism. A single-use card closes after its first approved purchase, so Vault is the better fit for ongoing merchants.

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

Which product should I use to isolate every AI purchase?

Does this mean the agent can never access my main account?

In Vault the agent never holds your card. It is encrypted with a passkey on your phone and swapped in at checkout, and each purchase is approved with Face ID or an auto approve threshold.

What happens after a single-use card is used?

With Issuing, the card closes after its first approved purchase. If the agent needs to buy something else, create a new card.

Will it work at every merchant?

No payment method can guarantee acceptance in every checkout flow. Vault works with any card from any country on Visa, Mastercard or Amex, but merchant rules, location and order type can affect a particular transaction. Test important flows before operationalizing them.

Conclusion

For a genuinely narrow purchasing permission, do not give an AI agent a durable card and hope software instructions contain it. 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 fit for your purchase flow, read the Agentcard card concepts documentation.