# Features

:::note{title="Beta"}

API Monetization is in beta and free to try. The APIs are stable but should be
evaluated in non-production environments first. To go to production, contact
[sales@zuplo.com](mailto:sales@zuplo.com). Production pricing has not yet been
announced.

:::

Features describe what your API offers to customers. They represent the
capabilities in your API product - access to specific endpoints, usage
allowances, premium functionality, or any other aspect you want to track or
gate.

## Metered vs Static Features

Features come in two types:

- **Metered features** are linked to a meter and track consumption. Use these
  for usage-based capabilities like API calls, tokens, or data transfer.
- **Static features** have no meter attached. Use these for boolean capabilities
  like "access to premium endpoints" or "priority support".

## Feature Properties

| Property    | Required | Description                                                            |
| ----------- | -------- | ---------------------------------------------------------------------- |
| `key`       | Yes      | Unique identifier (lowercase alphanumeric and underscores, 1-64 chars) |
| `name`      | Yes      | Human-readable display name                                            |
| `meterSlug` | No       | Links this feature to a meter for usage tracking                       |
| `metadata`  | No       | Custom key-value pairs for your own use                                |

:::note

Features cannot be updated after creation - they can only be archived. Plan your
feature structure carefully before creating them.

:::

## Creating a Feature

Create a metered feature linked to an API requests meter:

```shell
curl \
  https://dev.zuplo.com/v3/metering/$BUCKET_ID/features \
  --request POST \
  --header "Authorization: Bearer $ZAPI_KEY" \
  --header "Content-Type: application/json" \
  --data @- << EOF
{
  "key": "api_calls",
  "name": "API Calls",
  "meterSlug": "api_requests"
}
EOF
```

The response includes the created feature:

```json
{
  "id": "01ARZ3NDEKTSV4RRFFQ69G5FAV",
  "key": "api_calls",
  "name": "API Calls",
  "meterSlug": "api_requests",
  "createdAt": "2024-01-01T01:01:01.001Z",
  "updatedAt": "2024-01-01T01:01:01.001Z"
}
```

### Creating a Static Feature

For features without usage tracking, omit the `meterSlug`:

```shell
curl \
  https://dev.zuplo.com/v3/metering/$BUCKET_ID/features \
  --request POST \
  --header "Authorization: Bearer $ZAPI_KEY" \
  --header "Content-Type: application/json" \
  --data @- << EOF
{
  "key": "priority_support",
  "name": "Priority Support"
}
EOF
```

## API Reference

For complete API operations (list, get, archive), see the
[Features API Reference](../../api/metering-features).