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

# TopicFilter

```ts theme={null}
type TopicFilter: (null | string | string[])[];
```

A **TopicFilter** provides a struture to define bloom-filter queries.

Each field that is `null` matches **any** value, a field that is a `string` must match exactly that value and and
`array` is effectively an `OR`-ed set, where any one of those values must match.

## Source

[providers/provider.ts:2605](https://github.com/dominant-strategies/quais.js/blob/c1c12d43f9d34c6baad2b0542bd6d0acd6fefcbf/src/providers/provider.ts#L2605)