the default offset is 0, the default limit is 10 results. To get all results, use limit=0 as a parameter on the URL (ie, GET /events?limit=0).

GETs (reading data)

Alarms API GET functions
Resource Description


Get a list of alarms.


Get the number of alarms (returns plaintext, rather than XML or JSON).


Get the alarms specified by the given ID.

Note that you can also query by severity:

Resource Description


Get the alarms with a severity greater than or equal to MINOR.

PUTs (modifying data)

PUT requires form data using application/x-www-form-urlencoded as a Content-Type.

Alarms API PUT functions
Resource Description


Acknowledges (or unacknowledges) an alarm.


Acknowledges (or unacknowledges) alarms matching the additional query parameters (for example, /alarms?


Clears an alarm.


Escalates an alarm (for example, NORMAL → MINOR, MAJOR → CRITICAL).


Clears alarms matching the additional query parameters.


Escalates alarms matching the additional query parameters.

Additionally, when acknowledging alarms (ack=true) you can specify an ackUser parameter. You will only be allowed to ack as a different user if you are PUTting as an authenticated user who is in the admin role.

v2 API

Since Horizon 20.1.0, an alarms endpoint has been available in the v2 API that uses FIQL for querying.


  • /api/v2/alarms?*

  • /api/v2/alarms?

  • /api/v2/alarms?_s=alarm.ipAddr==

  • /api/v2/alarms?_s=node.label==localhost

If your query string includes a FIQL reserved character like a comma (,) or a semicolon (;) you need to double percent-escape it.

Suppose you have a service with a comma in the name, like COMMA,SERVICE and you want to retrieve all the alarms for its failure. Your query would look like /api/v2/alarms?*:COMMA%252CSERVICE.