> ## Documentation Index
> Fetch the complete documentation index at: https://docs.galileo.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# RetrieverSpanAllowedOutputType

***

# Type Alias: RetrieverSpanAllowedOutputType

```ts theme={null}
type RetrieverSpanAllowedOutputType =
  | string
  | Record<string, string>
  | Document
  | string[]
  | Record<string, string>[]
  | Document[];
```

Defined in: [src/types/logging/step.types.ts](https://github.com/rungalileo/galileo-js/blob/main/src/types/logging/step.types.ts)