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## Send defaults for optional parameters in the API Explorer

api-reference, docs.yml

You can now have the API Explorer pre-fill and send the declared `default` (or `x-fern-default`) of optional header, query, and path parameters. Set `playground.send-optional-defaults: true` in `docs.yml` on an API, section, or endpoint.

**`docs.yml`**

```yaml docs.yml {4}
navigation:
  - api: API Reference
    playground:
      send-optional-defaults: true
```

Read the docs