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

# Transactions V2

Transactions V2 is CPN's onchain transaction path. It enables secure and
compliant stablecoin settlement across all blockchains that
[CPN supports](/cpn/references/blockchains/supported-blockchains), managing gas
fees, signing, and orchestration on your behalf.

## Gas abstraction

Transactions V2 provides gas abstraction which removes the requirement for you
to pay native tokens for gas fees during transaction broadcast. This provides a
lower-complexity operational model for you by eliminating the need to acquire
and maintain a native token balance in your wallet.

When a Transaction V2 quote is created, the `fees` field includes a fixed gas
fee denoted in USDC. This gas fee is valid as long as the payment remains
active. During transaction settlement, the payment settlement smart contract
withdraws the fee amount from your wallet and distributes it to the beneficiary.

The transaction fee you pay is fixed regardless of fluctuations of the native
blockchain gas fee levels. CPN ensures that the transaction gets broadcast
accurately and on time. This removes the need for manual acceleration and
monitoring by delegating it to CPN.

## EVM payment settlement contract and `Permit2`

In EVM blockchains, Transactions V2 uses a payment settlement smart contract
that allows you to send verified payments to the BFI that are authorized by you,
an attester (CPN), and (optionally) the BFI. The contract ensures that the
transaction is accurate and correct, and can serve as proof of payment after the
transaction has settled.

The payment settlement contract uses the `Permit2` contract, Uniswap's universal
token approval system, for token approvals. `Permit2` makes integrations more
straightforward by using gasless, offchain signatures for token transfers.
`Permit2` permits are signature-based, time-bound, and single-use.

The payment settlement smart contract uses `Permit2` to execute funds transfer
from your wallet to the recipient wallet in a single contract execution. In
practice, this means that you sign an EIP-712 typed-data message of the
`PermitWitnessTransferFrom` method call to allow the payment settlement smart
contract to transfer USDC out of your wallet and into the recipient wallet.

```json JSON theme={null}
{
  "types": {
    "EIP712Domain": [
      {
        "name": "name",
        "type": "string"
      },
      {
        "name": "chainId",
        "type": "uint256"
      },
      {
        "name": "verifyingContract",
        "type": "address"
      }
    ],
    "PermitWitnessTransferFrom": [
      { "name": "permitted", "type": "TokenPermissions" },
      { "name": "spender", "type": "address" },
      { "name": "nonce", "type": "uint256" },
      { "name": "deadline", "type": "uint256" },
      { "name": "witness", "type": "PaymentIntent" }
    ],
    "TokenPermissions": [
      { "name": "token", "type": "address" },
      { "name": "amount", "type": "uint256" }
    ],
    "PaymentIntent": [
      { "name": "from", "type": "address" },
      { "name": "to", "type": "address" },
      { "name": "value", "type": "uint256" },
      { "name": "validAfter", "type": "uint256" },
      { "name": "validBefore", "type": "uint256" },
      { "name": "nonce", "type": "bytes32" },
      { "name": "beneficiary", "type": "address" },
      { "name": "maxFee", "type": "uint256" },
      { "name": "requirePayeeSign", "type": "bool" },
      { "name": "attester", "type": "address" }
    ]
  },
  "domain": {
    "name": "Permit2",
    "chainId": 11155111,
    "verifyingContract": "PERMIT2_ADDRESS"
  },
  "message": {
    "permitted": {
      "token": "0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238",
      "amount": "100050000"
    },
    "spender": "CPN_SMART_CONTRACT_ADDRESS",
    "nonce": "0",
    "deadline": "1234567890",
    "witness": {
      "from": "OFI_PAYER_ADDRESS",
      "to": "BFI_PAYEE_ADDRESS",
      "value": "100000000",
      "validAfter": "0",
      "validBefore": "1234567890",
      "nonce": "ONCHAIN_PAYMENT_REF",
      "beneficiary": "CIRCLE_BENEFICIARY_ADDRESS",
      "maxFee": "50000",
      "requirePayeeSign": false,
      "attester": "CPN_WALLET_ADDRESS"
    }
  },
  "primaryType": "PermitWitnessTransferFrom"
}
```

### `Permit2` allowance

The use of `Permit2` requires you to grant an allowance of USDC to the `Permit2`
contract ahead of the payment. This allowance grants the `Permit2` contract
permission to transfer USDC from your wallet in a CPN settlement. When you sign
a CPN transaction, that transaction allows the payment settlement contract to
consume the USDC allowance previously granted to `Permit2`.

The allowance amount can be set to a specific value based on the expected
payment volume or to the maximum `uint256` value for unlimited transfers. The
allowance is the foundational authorization that makes the entire CPN payment
settlement system possible through `Permit2`'s signature-based transfer
mechanism.