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

# Device ID

A Device ID is a unique identifier tied to a customer's device — phone, tablet, or browser. Banks link a device ID to a customer's lookup ID, enabling merchants to discover that customer automatically when they visit a site or app.

## How It Works

Banks link devices after onboarding a customer:

```bash theme={null}
curl -X POST "https://api.peere.network/v1/bank/customer/device/link" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "customerId": "customer_123",
    "phrase": "customer-unique-phrase",
    "deviceId": "device_789"
  }'
```

Merchants then pass the device ID when looking up a customer:

```bash theme={null}
curl -X POST "https://api.peere.network/v1/customer/device/lookup" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "deviceId": "device_789" }'
```