# Contacts API - Segments

> \[!WARNING]
>
> This covers the obsolete Legacy Marketing Campaigns API.

> \[!NOTE]
>
> For the most up-to-date information on the Segments API, please visit the [new Marketing Campaigns Segments v2 API](/docs/sendgrid/api-reference/segmenting-contacts-v2).

The Segments API allows you to create and manage segments for your contacts. Segments are used to group contacts based on conditions you set. For example, you might create a segment for contacts who have opened a certain number of your emails, or for contacts who have not opened any of your emails in the last 30 days.