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

# Device Fingerprinting

> Automatically capture browser, device, and location data for fraud prevention and dispute protection.

PayNext SDK automatically collects browser and device information during checkout. This data is stored in `metadata.fingerprint` and can be forwarded to processors, fraud providers, or used in custom workflows.

## Why Use Fingerprinting

* **Fraud prevention** — Share device data with processors to prevent fraudulent transactions
* **Dispute protection** — Provide evidence for Visa Order Insights/Consumer Clarity (OI/CE 3.0) and Mastercard Consumer Clarity programs
* **Transaction enrichment** — Enhance authorization requests with device data to improve acceptance rates
* **Chargeback defense** — Document customer device and location data to fight fraudulent disputes

## Collected Fields

Each client session automatically captures:

| Field                             | Description                       | Example                                              |
| :-------------------------------- | :-------------------------------- | :--------------------------------------------------- |
| `fingerprint.ip`                  | Customer IP address               | `203.0.113.42`                                       |
| `fingerprint.country`             | Country code (ISO 3166-1 alpha-2) | `US`                                                 |
| `fingerprint.city`                | City name                         | `Seattle`                                            |
| `fingerprint.latitude`            | Geographic latitude               | `47.6062`                                            |
| `fingerprint.longitude`           | Geographic longitude              | `-122.3321`                                          |
| `fingerprint.timezone`            | IANA timezone                     | `America/Los_Angeles`                                |
| `fingerprint.postal_code`         | Postal/ZIP code                   | `98101`                                              |
| `fingerprint.country_region_code` | State/region code                 | `WA`                                                 |
| `fingerprint.country_region_name` | State/region name                 | `Washington`                                         |
| `fingerprint.user_agent`          | Browser user agent string         | `Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7)...` |
| `fingerprint.accept_language`     | Browser language preferences      | `en-US,en;q=0.9`                                     |

<Info>
  Fingerprint data is derived from the customer's browser at checkout time. IP geolocation accuracy varies by region.
</Info>

## Example Fingerprint Object

```json theme={"system"}
{
  "metadata": {
    "fingerprint": {
      "ip": "203.0.113.42",
      "country": "US",
      "city": "Seattle",
      "latitude": "47.6062",
      "longitude": "-122.3321",
      "timezone": "America/Los_Angeles",
      "postal_code": "98101",
      "country_region_code": "WA",
      "country_region_name": "Washington",
      "user_agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.0 Safari/605.1.15",
      "accept_language": "en-US,en;q=0.9"
    }
  }
}
```

## Use Cases

### Forward to Payment Processors

Use [Metadata Mapping](/guides/advanced/metadata-mapping) to forward fingerprint fields to your payment processor. Map fields like `fingerprint.ip` to the corresponding processor field for enhanced fraud scoring.

### Visa OI/CE 3.0 & Mastercard Consumer Clarity

Transaction enrichment programs use device and location data to reduce chargebacks. When a cardholder disputes a transaction, the card network shows them:

* Device type and browser used
* Geographic location at purchase time
* IP address

This helps cardholders recognize legitimate purchases, reducing friendly fraud disputes.

### Chargeback Evidence

When responding to disputes, include fingerprint data as evidence:

* **IP address** — Shows customer's network location
* **Geolocation** — Matches shipping address or known customer location
* **User agent** — Identifies device type (mobile, desktop)
* **Timezone** — Correlates with customer's expected location

<Note>
  Fingerprint data is read-only and available on payment and customer objects. The SDK populates it automatically—don't overwrite the `fingerprint` namespace.
</Note>