[[add-fields]]
=== Add fields

++++
<titleabbrev>add_fields</titleabbrev>
++++

The `add_fields` processor adds additional fields to the event.  Fields can be
scalar values, arrays, dictionaries, or any nested combination of these. 
The `add_fields` processor will overwrite the target field if it already exists. 
By default the fields that you specify will be grouped under the `fields`
sub-dictionary in the event. To group the fields under a different
sub-dictionary, use the `target` setting. To store the fields as
top-level fields, set `target: ''`.

`target`:: (Optional) Sub-dictionary to put all fields into. Defaults to `fields`.
`fields`:: Fields to be added.


For example, this configuration:

[source,yaml]
------------------------------------------------------------------------------
processors:
  - add_fields:
      target: project
      fields:
        name: myproject
        id: '574734885120952459'
------------------------------------------------------------------------------

Adds these fields to any event:

[source,json]
-------------------------------------------------------------------------------
{
  "project": {
    "name": "myproject",
    "id": "574734885120952459"
  }
}
-------------------------------------------------------------------------------
