**Use this endpoint to locate contacts**. The request body's `query` field accepts valid [SGQL](https://sendgrid.com/docs/for-developers/sending-email/segmentation-query-language/) for searching for a contact. Because contact emails are stored in lower case, using SGQL to search by email address requires the provided email address to be in lower case. The SGQL `lower()` function can be used for this. Only the first 50 contacts that meet the search criteria will be returned. If the query takes longer than 20 seconds, a `408 Request Timeout` status will be returned. Formatting the `created_at` and `updated_at` values as Unix timestamps is deprecated. Instead they are returned as ISO format as string. Twilio SendGrid recommends exporting your contacts regularly as a backup to avoid issues or lost data.