You can define processors in your configuration to process events before they are sent to the configured output. The libbeat library provides processors for:

Each processor receives an event, applies a defined action to the event, and returns the event. If you define a list of processors, they are executed in the order they are defined in the Metricbeat configuration file.

event -> processor 1 -> event1 -> processor 2 -> event2 ...

For example, the following configuration reduces the exported fields by dropping the agent.name and agent.version fields under beat from all documents.

processors:
  - drop_fields:
      fields: ['agent']