> ## Documentation Index
> Fetch the complete documentation index at: https://x402.easy-node.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# x402 Protocol

The [x402 protocol](https://www.x402.org/) enables seamless machine-to-machine payments using HTTP status codes. It extends HTTP with a payment flow based on the `402 Payment Required` status code.

## How It Works

The payment flow is fully automated by the MCP server:

<Steps>
  <Step title="Agent calls create_order">
    The AI agent calls `create_order` or `renew_instance` with product details.
  </Step>

  <Step title="Server returns HTTP 402">
    The first request returns HTTP 402 with a `payment-required` header containing payment requirements (amount, recipient, asset, network).
  </Step>

  <Step title="Client signs payment">
    The MCP client signs a USDC transfer authorization using EIP-3009 (TransferWithAuthorization) — no on-chain transaction needed at this point.
  </Step>

  <Step title="Retry with signature">
    The request is retried with the payment signature in the `payment-signature` header.
  </Step>

  <Step title="Server verifies and settles">
    The server verifies the signature, settles the USDC transfer on-chain (Base network), and creates the order.
  </Step>

  <Step title="Order returned">
    The completed order is returned to the agent with instance details.
  </Step>
</Steps>

## EIP-3009: TransferWithAuthorization

The payment uses [EIP-3009](https://eips.ethereum.org/EIPS/eip-3009) which allows gasless USDC transfers via signed authorizations:

* **No gas needed** — The wallet signs a typed data message (EIP-712), not a transaction
* **Server submits** — The server submits the authorization on-chain
* **USDC only** — Only works with USDC on Base network
* **Time-bounded** — Authorization has `validAfter` and `validBefore` timestamps
* **Nonce-protected** — Each authorization uses a unique random nonce

## Payment Payload Structure

The signed payment is encoded as a base64 JSON payload:

```json theme={null}
{
  "x402Version": 2,
  "resource": {
    "url": "https://api.easy-node.xyz/api/x402/order",
    "description": "Order creation",
    "mimeType": "application/json"
  },
  "accepted": {
    "scheme": "exact",
    "network": "eip155:8453",
    "amount": "5000000",
    "payTo": "0x...",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
  },
  "payload": {
    "authorization": {
      "from": "0x...",
      "to": "0x...",
      "value": "5000000",
      "validAfter": "...",
      "validBefore": "...",
      "nonce": "0x..."
    },
    "signature": "0x..."
  }
}
```