> ## Documentation Index
> Fetch the complete documentation index at: https://docs.crossmint.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Overview

> Payment infrastructure for AI agents

Enable agents to pay with **cards or stablecoins**, all under **spending rules defined and controlled by your users**. Integrate via a white-label SDK that plugs into your agent framework as a tool or skill without handling sensitive credentials and while being PCI-compliant.

## Crossmint takes care of

* PCI-compliant card vaulting and tokenization
* Visa VIC and Mastercard Agent Pay integrations
* Non-custodial wallet infrastructure and onramps
* Spending rule enforcement and user authorization flows
* Direct API checkout via [Fast Checkout](/agents/payment-flows/worldstore/inventory)

## Payment methods

How users fund agent payments, with controlled access to spending sources.

<CardGroup cols={2}>
  <Card title="Card permissions for agents" icon="credit-card" href="/agents/cards-quickstart">
    Users verify their card once, then give agents scoped permissions to use it with spending rules. Payments are secured via Visa VIC, Mastercard Agent Pay, and more.
  </Card>

  <Card title="Stablecoin wallets" icon="wallet" href="/agents/stablecoin-wallet-quickstart">
    Non-custodial, user-controlled wallets that grant agents scoped spending access.
  </Card>
</CardGroup>

## Payment Flows

How agents execute payments across checkouts, APIs, and machine-to-machine paths.

<CardGroup cols={2}>
  <Card title="Browser Checkouts" icon="browser" href="/agents/payment-flows/browser-checkout">
    Make your agent drive a browser and complete the checkout form using a secure card number. Works anywhere cards are accepted.
  </Card>

  <Card title="x402" icon="bolt" href="/agents/payment-flows/x402">
    HTTP-native micropayments where agents pay in stablecoins on a per-use basis.
  </Card>

  <Card title="Fast Checkout" icon="rocket" href="/agents/payment-flows/worldstore/inventory">
    A single API call for checkout at supported merchants in the US (Amazon and Shopify stores). No browser needed.
  </Card>

  <Card title="MPP" icon="arrows-left-right" href="/agents/payment-flows/mpp">
    A protocol for agent-to-agent and service-to-service payments. Best for programmatic machine economies.
  </Card>
</CardGroup>

## Payment Methods × Payment Flows

Each payment method works with a specific set of flows. The matrix below shows what's supported today.

<Frame type="simple">
  <img className="block dark:hidden" src="https://mintcdn.com/crossmint/JZTN1lu8hkPiJvpV/images/agents/payment-methods-x-payment-flows-light.png?fit=max&auto=format&n=JZTN1lu8hkPiJvpV&q=85&s=90bdef70c8b6a03c579b4e6cfdbb9fba" alt="Matrix showing which payment flows (x402, MPP, Fast Checkout, Browser Checkout, Send Stablecoins) are supported by cards and stablecoin wallets" width="2012" height="566" data-path="images/agents/payment-methods-x-payment-flows-light.png" />

  <img className="hidden dark:block" src="https://mintcdn.com/crossmint/JZTN1lu8hkPiJvpV/images/agents/payment-methods-x-payment-flows-dark.png?fit=max&auto=format&n=JZTN1lu8hkPiJvpV&q=85&s=0f483c6e46cfec3d1f64e8c3eb5d62f6" alt="Matrix showing which payment flows (x402, MPP, Fast Checkout, Browser Checkout, Send Stablecoins) are supported by cards and stablecoin wallets" width="2006" height="654" data-path="images/agents/payment-methods-x-payment-flows-dark.png" />
</Frame>

## Pick your path

Use this table to choose the right integration:

| If your agent needs to…                                              | Use                                                                                    | Pay via                                                                |
| :------------------------------------------------------------------- | :------------------------------------------------------------------------------------- | :--------------------------------------------------------------------- |
| Buy from any website with a checkout                                 | [Card](/agents/cards-quickstart)                                                       | [Browser Checkout](/agents/payment-flows/browser-checkout)             |
| Pay per API call or to another agent (micropayments)                 | [Stablecoin](/agents/stablecoin-wallet-quickstart)                                     | [x402](/agents/payment-flows/x402) or [MPP](/agents/payment-flows/mpp) |
| Buy from Amazon, any Shopify store, and other supported US merchants | [Card](/agents/cards-quickstart) or [stablecoin](/agents/stablecoin-wallet-quickstart) | [Fast Checkout](/agents/payment-flows/worldstore/inventory)            |

## Get started

<CardGroup cols={3}>
  <Card title="How agents pay" icon="diagram-project" href="/agents/how-agents-pay">
    The full mental model, payment methods, spending rules, and destinations.
  </Card>

  <Card title="Cards quickstart" icon="credit-card" href="/agents/cards-quickstart">
    Get an agent paying with card permissions.
  </Card>

  <Card title="Wallets quickstart" icon="wallet" href="/agents/stablecoin-wallet-quickstart">
    Get an agent paying with stablecoins.
  </Card>
</CardGroup>