# PricingMode

Specifies how a transaction's execution cost is calculated and paid. Casper 2.x supports three pricing modes.

## Import

```ts
import { PricingMode, PaymentLimitedMode, FixedMode, PrepaidMode } from 'casper-js-sdk';
```

## Classes

### `PricingMode`

A discriminated union - exactly one mode is active.

| Property | Type | Description |
|---|---|---|
| `paymentLimited?` | `PaymentLimitedMode` | Classic payment with an explicit amount |
| `fixed?` | `FixedMode` | Fixed-cost execution |
| `prepaid?` | `PrepaidMode` | Pre-paid via a receipt |

#### Methods

```ts
pricingMode.toBytes(): Uint8Array
```

### `PaymentLimitedMode`

Classic payment model: the caller sets a maximum payment amount.

| Property | Type | Description |
|---|---|---|
| `gasPriceTolerance` | `number` | Maximum acceptable gas price multiplier |
| `paymentAmount` | `number` | Maximum payment in motes |
| `standardPayment` | `boolean` | Whether to use the standard payment contract |

#### Methods

```ts
mode.toBytes(): Uint8Array
```

### `FixedMode`

Fixed-cost execution - used by the system for auction and mint transactions.

| Property | Type | Description |
|---|---|---|
| `gasPriceTolerance` | `number` | Maximum acceptable gas price multiplier |
| `additionalComputationFactor` | `number` | Extra computation factor |

#### Methods

```ts
mode.toBytes(): Uint8Array
```

### `PrepaidMode`

Execution paid for by a pre-purchased receipt.

| Property | Type | Description |
|---|---|---|
| `receipt` | `Hash` | Pre-payment receipt hash |

#### Methods

```ts
mode.toBytes(): Uint8Array
```

## Usage

```ts
import { PricingMode, PaymentLimitedMode, FixedMode } from 'casper-js-sdk';

// Payment limited mode (most common for user transactions)
const paymentLimited = new PricingMode();
paymentLimited.paymentLimited = new PaymentLimitedMode();
paymentLimited.paymentLimited.paymentAmount = 100_000_000;
paymentLimited.paymentLimited.gasPriceTolerance = 1;
paymentLimited.paymentLimited.standardPayment = true;

// Fixed mode (for auction/mint calls)
const fixed = new PricingMode();
fixed.fixed = new FixedMode();
fixed.fixed.gasPriceTolerance = 1;
fixed.fixed.additionalComputationFactor = 0;
```

:::tip
Transaction builders like `NativeTransferBuilder` set the pricing mode automatically. You only need to configure it manually when building raw `TransactionV1Payload` objects.
:::

## See Also

- [`TransactionV1Payload`](/types/transaction-v1-payload) - Uses `PricingMode`
- [Transaction Builders](/builders/introduction) - Handle pricing automatically