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

# Payment Protocols

> Understand agent payment protocols, how ProtocolRouter unifies verification, and when to use Visa TAP, Google AP2, or Mastercard VI.

# Payment Protocols

Agent payment protocols let autonomous systems prove intent, permissions, and constraints before money moves.

## Why Protocols Matter

## Supported Standards

## Supported Protocols

* Visa TAP with RFC 9421
* Google AP2 mandates
* Mastercard VI SD-JWT

## ProtocolRouter

ProtocolRouter gives you a unified entry point for payment verification so each protocol can be normalized behind one decision surface.

```ts title="protocol-router.ts" theme={null}
const verification = await protocolRouter.verify({
  protocol: request.protocol,
  headers: request.headers,
  body: request.body,
  featureFlags: {
    visaTap: true,
    googleAp2: true,
    mastercardVi: true,
  },
  fallback: "deny",
});
```

## Quick Comparison

| Protocol      | Primary Primitive        | Best Fit                       | Delegation Model              |
| ------------- | ------------------------ | ------------------------------ | ----------------------------- |
| Visa TAP      | HTTP signatures + nonces | Real-time API authorization    | Key-based agent identity      |
| Google AP2    | Mandates + capabilities  | Checkout and shopping tasks    | Multi-hop narrowing chain     |
| Mastercard VI | SD-JWT credentials       | Constrained delegated payments | L1 → L2 → L3 credential chain |

> **Note:** Recommendation: normalize all protocol outputs into one internal policy schema so fraud and limit engines stay protocol-agnostic.

## Explore by Protocol

* visa-tap
* ap2
* mastercard-vi