---
title: Specifying Fields
subtitle: >-
  Control which fields are returned in responses and how to update only specific
  fields.
slug: /api/overview/fields
---

## Filtering Response Fields

Most endpoints support a `_fields` parameter that lets you specify which fields
you require in the response. For example, if you only need `id` and
`display_name` when listing Leads, add `?_fields=id,display_name` to the URL.
This will improve performance of your API calls.

In some cases, an API response can include fields that are not listed in the
sample response for that endpoint below. Non-custom fields that are not included
in the sample response for an endpoint should not be used in integrations, as
they may change without warning.

## Updating Specific Fields

In the Close API, every `PUT` request behaves as a `PATCH`. What this means is that
you don't need to send all the fields with every request. For example, if only
the `title` field changed for a specific Contact, there's no need to include the
`name` field in the request.