## List Keys

`v1.custom_fields.list_keys(**kwargs) -> CustomFieldListKeysResponse`

**post** `/v1/customFields/listKeys`

List all active custom field keys, optionally filtered by entity type.

### Parameters

- **next\_page:** `String`

  Cursor that indicates where the next page of results should start.

- **entities:** `Array[:alert | :billable_metric | :charge | 15 more]`

  Optional list of entity types to return keys for

  - `:alert`

  - `:billable_metric`

  - `:charge`

  - `:commit`

  - `:contract_credit`

  - `:contract_product`

  - `:contract`

  - `:credit_grant`

  - `:customer_plan`

  - `:customer`

  - `:discount`

  - `:invoice`

  - `:plan`

  - `:professional_service`

  - `:product`

  - `:rate_card`

  - `:scheduled_charge`

  - `:subscription`

### Returns

- `class CustomFieldListKeysResponse`

  - **data:** `Array[{ enforce_uniqueness, entity, key}]`

    - **enforce\_uniqueness:** `bool`

    - **entity:** `:alert | :billable_metric | :charge | 15 more`

      - `:alert`

      - `:billable_metric`

      - `:charge`

      - `:commit`

      - `:contract_credit`

      - `:contract_product`

      - `:contract`

      - `:credit_grant`

      - `:customer_plan`

      - `:customer`

      - `:discount`

      - `:invoice`

      - `:plan`

      - `:professional_service`

      - `:product`

      - `:rate_card`

      - `:scheduled_charge`

      - `:subscription`

    - **key:** `String`

  - **next\_page:** `String`

### Example

```ruby
require "metronome_sdk"

metronome = MetronomeSDK::Client.new(bearer_token: "My Bearer Token")

response = metronome.v1.custom_fields.list_keys

puts(response)
```