> ## Documentation Index
> Fetch the complete documentation index at: https://docs-dev-docs-event-stream-action-templates.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# CustomOptions

```ts Example theme={null}
export interface CustomOptions {
  [key: string]: string | number | boolean | undefined;
}
```

## Properties

<ParamField body="[`key`: `string`]" type="&#x22;string&#x22; | &#x22;number&#x22; | &#x22;boolean&#x22; | &#x22;undefined&#x22;">
  Additional custom fields prefixed with `ulp-` (for example, `'ulp-custom-field'`).
</ParamField>