Deprecation Note

We published the last version of Graylog Documentation before the release of Graylog 4.2. Now, all documentation and help content for Graylog products are available at

There will be no further updates to these pages as of October 2021.

Do you have questions about our documentation? You may place comments or start discussions about documentation here:


Decorators can be used to transform a message field at display time. Multiple decorators can be applied at the same time, but you cannot make any assumptions about their order, as that is user defined. Stacked decorators receive the value of the previous decorator results.

They are typically used to map between the stored value and a human readable form of that value, for example like the Syslog severity mapper (compare its code) maps between numeric values and their textual representation.

Other uses include looking up user names based on a user’s ID in a remote database, triggering a whois request on a domain name etc.

Class Overview

You need to implement the org.graylog2.plugin.decorators.SearchResponseDecorator interface. This class must declare a Factory Class.

Beyond the factory, configuration and descriptor classes, the only thing that a decorator needs to implement is the apply function:

SearchResponse apply(SearchResponse searchResponse);

The class represents the result that is being returned to the web interface (or other callers of the REST API).

You are free to modify any field, create new fields or remove fields. However, the web interface makes certain assumptions regarding fields that start with gl2_ and requires at least the timestamp, source and message fields to be present.

Thrown exceptions are being logged as errors and lead to returning the original search response, without any modifications.


Please refer to the sample plugin implementation for the full code.


Compare with the code in the sample plugin.

public class SampleModule extends PluginModule {

  public Set<? extends PluginConfigBean> getConfigBeans() {
      return Collections.emptySet();

  protected void configure() {

User Interface

Decorators have no custom user interface elements.