How to Choose a Card Issuing API for Autonomous AI Agents: Start with Vault

Start with Vault. Most teams asking about card issuing APIs for agents do not need to fund cards or hold balances at all. Agentcard Vault lets users store their own card once, encrypted with a passkey, approve each purchase with Face ID, and have Agentcard swap the real card in at checkout. There is no KYC, no balance to fund, and users keep their points and dispute rights. Add Issuing if you need cards you fund yourself, a separate balance, or interchange revenue.

Introduction

Historically, giving an AI agent purchasing power meant pre-funding a digital wallet or maintaining an upfront balance. That ties up working capital and adds accounting friction, especially across fleets of agents. It also means the builder takes on card issuing, compliance and KYC.

The first question to ask is whether you need to issue cards at all. If your users already have cards, a Vault that uses their own card at checkout avoids funding, balances and issuer onboarding. Issuing is the right tool when you do want cards you fund yourself.

Key Takeaways

Start with Vault: no KYC, no balance to fund, onboarding is entering a card once.
Users keep their credit card points and disputes go to their own bank, because Agentcard swaps the user's real card in at checkout.
Vault works with any card from any country on Visa, Mastercard or Amex.
Add Issuing for cards you fund yourself, single-use cards, a separate balance or interchange revenue. Both can run side by side.
Compare any option on funding model, KYC requirements, card coverage and controls.

Why This Solution Fits

AI agents make dynamic, unpredictable purchases, such as per-request API costs, datasets or software. Guessing how much capital to put in each agent's balance creates overhead and traps cash. Some issuing APIs address this with real-time authorization that approves or denies funds as transactions happen.

Vault sidesteps the question. The agent asks to buy, the user approves with Face ID, and the user's own card pays at checkout. Nothing is pre-loaded, the builder does not hold funds, and onboarding does not involve KYC. Auto approve thresholds handle small purchases, and a trusted agent signature and timestamped approval log record each one.

When you do want to issue cards, Issuing covers it: cards you fund, a separate balance, single-use cards, and interchange revenue. Issuing funds a per-user wallet and is $5,000/mo plus 1% revenue share. Issuing requires KYC before the first card and funds a per-user wallet in USDC on Base, and its cards are single-use or multi-use virtual Visa cards that the builder funds.

Key Capabilities

Vault. Encrypted with a passkey on the user's phone so neither the agent, the builder nor Agentcard can read the card. 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. Free up to 5,000 users then enterprise, and fully white-labeled. A rewards card router picks the best card for each purchase.

Coverage and speed. 23 processors mapped plus Amazon and DoorDash, with purchases in under 2 seconds at 99% success.

Issuing. Cards the builder funds, single-use cards, a separate balance and interchange revenue, side by side with Vault.

Purchase Agent. One /buy call or the buy tool over MCP, 18+ merchants, live in an afternoon, $0.15 a request and free in beta.

Proof & Evidence

Just-in-Time funding models, such as Marqeta's, reduce capital lockup compared with pre-funded wallets, and they remain issuing products: the builder still operates a card program. Vault takes a different route by using the user's own card, so there is nothing to fund.

On security, published industry security checklists advise against exposing a primary corporate card to autonomous workflows. Vault addresses this by keeping the card encrypted and out of the agent's reach, with approval on every purchase.

Buyer Considerations

When evaluating card issuing APIs for autonomous agents, start with the funding model. Do you need to hold balances and fund cards, or can the user's own card pay? Vault needs no balance. Issuing is for when you want to fund cards yourself.

Check onboarding requirements. Vault needs no KYC and onboarding is entering a card once.

Check card coverage. Vault works with any card from any country on Visa, Mastercard or Amex.

Check controls: Face ID approval, auto approve thresholds, a trusted agent signature, a timestamped approval log, and for Issuing, single-use cards.

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

How does an agent pay if there is no pre-funded wallet?

In Vault the user's own card pays at checkout. The agent requests the purchase, the user approves with Face ID, and Agentcard swaps the real card in.

Are single-use virtual cards secure for AI agents?

Single-use cards limit what a card can be used for after the intended checkout. They are available through Issuing, which funds a per-user wallet. Vault avoids issuing a card to the agent at all.

Where can the agent use these?

Vault works with any card from any country on Visa, Mastercard or Amex, and Agentcard has 23 processors mapped plus Amazon and DoorDash.

How quickly can I integrate?

For users, onboarding is entering a card once. The Purchase Agent can be live in an afternoon.

Conclusion

Choosing a payment approach for AI agents starts with whether you need to issue cards at all. Many teams do not.