# Smart optimization of authentication requests

Use our intelligent acceptance engine to automatically optimize your authentication requests. The engine analyzes global transactions and the impact on the different fields in order to achieve the highest acceptance rates possible.

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## Acceptance rate optimization

In your [Standalone API request](https://api-reference.checkout.com/#tag/Standalone), set the `optimization.framework` field to `acceptance_rates`. The engine will then use machine learning to look at field performance and adjust some values in the authentication request, thus optimizing for higher acceptance rates.

### Request example

```json
{
  "source": {
    "type": "card",
    "number": "4485040371536584",
    "expiry_month": 1,
    "expiry_year": 2030
  },
  "amount": 100,
  "currency": "USD",
  "authentication_type": "regular",
  "authentication_category": "payment",
  "optimization": {
    "framework": "acceptance_rates"
  },
  "reference": "ORD-5023-4E89",
  "transaction_type": "goods_service",
  "shipping_address": {
    "address_line1": "123 High St.",
    "address_line2": "Flat 456",
    "city": "London",
    "state": "UK",
    "zip": "SW1A 1AA",
    "country": "GB"
  },
  "completion": {
    "type": "non_hosted",
    "callback_url": "https://example.com/sessions/callback"
  }
}
```

### Optimization values

If you’ve performed an optimized payment request, you'll receive the following fields in the response:

| Field name | Description |
| --- | --- |
| `optimization`<br><br>`object` | The object that contains information about the optimization. |
| `optimization.optimized`<br><br>`boolean` | Indicates whether the authentication was optimized |
| `optimization.framework`<br><br>`string` | The optimization framework applied |
| `optimization.optimized_properties`<br><br>`object` | The array of fields optimized by the optimization framework |
| `optimization.fields[].property_name`<br><br>`string` | The name of the optimized authentication request property. |
| `optimization.fields[].optimized_value`<br><br>`string` | The optimized value |

### Response example

```json
{
  "optimization": {
    "optimized": true,
    "framework": "acceptance_rates",
    "optimized_properties": [
      {
        "field": "challenge_indicator",
        "original_value": "no_preference",
        "optimized_value": "transaction_risk_assessment"
      },
      {
        "field": "authentication_type",
        "original_value": "regular",
        "optimized_value": "recurring"
      }
    ]
  }
}
```