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

# Expanding Fields

> Request the extra fields not in responses by default.

Some fields come back `null` until you ask for them, using the following parameter in a request:

<ParamField query="expand" type="string">
  A comma-separated list of fields to resolve. Each endpoint's reference page lists the values it accepts.
</ParamField>

For example, resolving the connector and its version on a connector profile:

```bash theme={null}
curl "https://api.stackone.com/v2/connector_profiles?expand=connector,version" \
  -u "$STACKONE_API_KEY:"
```

## What expanding changes

Without it, the profile carries the connector key, but the connector itself and the version are `null`:

```json theme={null}
{
  "id": "cp_123",
  "name": "Workday production",
  "connector_key": "workday",
  "connector": null,
  "version": null,
  "active": true
}
```

With `expand=connector,version`, both come back resolved:

```json theme={null}
{
  "id": "cp_123",
  "name": "Workday production",
  "connector_key": "workday",
  "connector": {
    "key": "workday",
    "name": "Workday",
    "categories": ["hris"],
    "release_stage": "ga"
  },
  "version": {
    "resolved": "1.4.0",
    "pinned": null,
    "owner": "stackone"
  },
  "active": true
}
```

## Ask for what you need

Expand the fields you are about to use, and no more. Some values run an aggregation across the project or return a large payload, so asking for everything on a long list is slow for no benefit. Each reference page says which of its values are the expensive ones.