Warning! This page documents an earlier version of Kapacitor, which is no longer actively developed. Kapacitor v1.5 is the most recent stable version of Kapacitor.

In addition to defining alert handler in TICKscript Kapacitor supports an alert system that follows a publish subscribe design pattern. Alerts are published to a topic and handlers subscribe to a topic.


An alert topic is simply a namespace where alerts are grouped. When an alert event fires it is assigned to a topic. Multiple handlers can be defined on a topic and all handlers process each alert event for the topic.


A handler takes action on incoming alert events for a specific topic. Each handler operates on exactly one topic.

A handler definition has a few properties:

  • ID - The unique ID of the handler.
  • Kind - The kind of handler, see handlers for a list of available kinds.
  • Match - A lambda expression to filter matching alerts. By default all alerts match, see matching for details on the match expression.
  • Options - A map of values, differs by kind.


See the Using Alert Topics example for a walk through defining and using alert topics.