# Field Specifications

NPS APIs support a common set of field definitions.

## Field Types

| Type | Details | Allowed Values | Default Values |
|  --- | --- | --- | --- |
| Boolean |  | `True`  `False` |  |
| Integer | 64 bits | `[0-9]` |  |
| Big Decimal Float Double | 32 bits | `.[0-9]` |  |
| String | * Unicode 16  * deserialize "null" -> NULL  * serialize never produce "null" if it is null | `.*` |  |
| List | Large lists use pagination |  | empty |
| Currency | ISO4127 |  | `USD` |
| Country Code | ISO2166-1/3 |  | `US` or `USA` |
| Region | ISO3166 | `[A-Z]{2:3}` | `null` |
| Datetime | ISO8601 | `2026-07-04T13:33:03.969Z` |  |
| Date  |  | `2026-07-04` |  |
| Enum  | Values are UPPERCASE | `[A-Z]*` |  |


*Note: Values labeled as null are not returned as int(0) or string("null").  They are returned as null objects.*

## Common Fields

| Field | Type | Description |
|  --- | --- | --- |
| amount | [big decimal](#bigdecimal) | The amount of the transaction. |
| firstName | [string](#string) | The user's first or given name. |
| lastName | [string](#string) | The user's last or surname. |
| username | [string](#string) | A unique identifier, account name, or login name identifying a user with access to an account or resource. |
| password | [string](#string) | A string of characters used to confirm a user's identity. When the password is correctly matched to the username, the user will receive access to an account or resource. |
| userStatus | [enum](#enum) | The status of the user's account. |
| lastLoggedIn | [datetime](#datetime) | The last day and time a user logged in. |