# libtmux.query:required-relations

- **Package:** libtmux/query
- **Language:** Common Lisp
- **Kind:** function
- **Source:** https://github.com/libtmux/libtmux-lisp/blob/c2e5fc4ed3befda21f45dfa5d5868c38fd138311/src/query.lisp#L602
- **Public owner:** libtmux.query
- **Page:** https://libtmux.org/en/lisp/latest/reference/libtmux-query-required-relations/

```
(required-relations filter)
```

Return a fresh vector of relation fields in first-occurrence order.

## Parameters

- `filter`

## Guides

Pages that discuss `required-relations`.

- [Native queries](/en/lisp/latest/guides/queries/)