curl --request GET \
  --url https://api.grainfinance.co/v1/customers \
  --header 'Authorization: Basic <encoded-value>'

{
  "customers": [
    {
      "id": "1b0ada1e-fa1b-4cfe-a553-01b340c5650e",
      "companyName": "Ollivander's Wand Shop",
      "companyCountry": "GB",
      "externalCustomerId": "630231b3ae0d7e9e5097ad35",
      "status": "Pending",
      "companyAddress": "12 Diagon Alley",
      "companyCity": "London",
      "companyState": "London",
      "contactEmail": "customer@company.com",
      "contactFullName": "Garrick Ollivander",
      "contactPhoneNumber": "+12125551234",
      "companyTaxId": "123-45-6789",
      "extraFields": {
        "field_a": "value_a",
        "field_b": "value_b"
      }
    }
  ],
  "pagination": {
    "page": 2,
    "perPage": 50.5,
    "totalResults": 123
  }
}