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

# Custom Fields

Many applications let users create custom object fields.

When a [Data Collection](/reference/workspace-elements/data-collections) supports custom fields, it will have:

* `customFields` set to `true` in its specification.
* `fieldsSchema` include both standard and custom fields.

In most cases you should simply work with `fieldsSchema` and not worry about doing anything special about custom fields.

## See also

<Columns cols={2}>
  <Card title="Data Schemas" href="/docs/references/data-schemas" target="_blank">
    Representing data structures used in integrations.
  </Card>

  <Card title="Data Sources" href="/reference/workspace-elements/data-sources" target="_blank">
    Configuring access to data in external apps.
  </Card>
</Columns>