[role="xpack"]
[testenv="basic"]
[[eql-requirements]]
== EQL requirements
++++
<titleabbrev>Requirements</titleabbrev>
++++

EQL is schemaless and works out-of-the-box with most common log formats. If you
use a standard log format and already know what fields in your index contain
event type and timestamp information, you can skip this page.

[discrete]
[[eql-required-fields]]
=== Required fields

In {es}, EQL assumes each document in an index corresponds to an event.

To search an index using EQL, each document in the index must contain the
following field archetypes:

Event type::
A field containing the event classification, such as `process`, `file`, or
`network`. This is typically mapped as a <<keyword,`keyword`>> field.

Timestamp::
A field containing the date and/or time the event occurred. This is typically
mapped as a <<date,`date`>> field.

[TIP]
====
While no schema is required to use EQL in {es}, we recommend the
{ecs-ref}[Elastic Common Schema (ECS)]. {es}'s EQL search is designed to work
with core ECS fields by default.
====