API Reference

For most users, the sample scripts from the Setup Guide will do the job just fine. But if you want more fine-grained control—for instance, to create high- and low-priority tickets for different types of system events—then you’ll have to customize the data those scripts send to Zammad.


This custom script will automatically set all tickets it creates to high priority and assign them to charlie@chrispresso.com.


curl -X POST \
  -F "host=$NOTIFY_HOSTNAME" \
  -F "state=$NOTIFY_HOSTSTATE" \
  -F "priority=3 high" \
  -F "owner=charlie@chrispresso.com" \

How does it work?

There are two kinds of data you can pass to the API, both in the form of key-value pairs:

Checkmk parameters

are required, and make up the contents of the resulting tickets/articles. They also determine whether an event creates a new ticket or updates/closes an existing one.

These are the only values used in the sample scripts. Use them as-is; technically, they can be customized, but it’s hard to imagine a good reason for it.

Ticket attributes

are optional, and can be used to adjust settings on newly created tickets (e.g., set the owner, group, priority, or state).

If you want to customize your Checkmk alert script, do it with these. Simply add an extra “form” option for each one (-F "key=value") to your script’s curl command line, as in the example above.


💡 It’s just an API endpoint!

When using Checkmk integration, messages need to be formatted in a certain way, but that doesn’t mean the messages actually have to come from Checkmk.

If you use another monitoring tool that’s not officially supported by Zammad, there’s probably a way to make it work with your Checkmk callback URL.

Checkmk Parameters

When a notification is received, Zammad creates a new article containing the details of the event that triggered it:

Checkmk article body

These details come from the fields listed below, which correspond to parameters provided by Checkmk ($NOTIFY_*).

Required fields are marked with an asterisk (*).




The hostname of the system that the event originated from. ($NOTIFY_HOSTNAME)

Used to determine if a new event belongs to an existing ticket. Also used in the subject line of the resulting article (“<host> is <state>”).


The name of the service that the event originated from. ($NOTIFY_SERVICEDESC)

Used to determine if a new event belongs to an existing ticket.

Displayed as - when omitted.


The current state of the service or host in question. ($NOTIFY_SERVICESTATE / $NOTIFY_HOSTSTATE)

Used to detect when a ticket should be auto-closed (i.e., on OK/UP). Also used in the subject line of the resulting article (“<host> is <state>”).


The output of the process that triggered the event. ($NOTIFY_SERVICEOUTPUT / $NOTIFY_HOSTOUTPUT)

Displayed as - when omitted.

Ticket Attributes

The Object Manager attribute panel displays built-in and custom attribute names.

Find a complete list of ticket attributes in the Object Manager.

Ticket attributes are entirely optional, and can be used to customize the tickets that Checkmk creates. (Note that these attributes will be ignored if a new event belongs to an existing ticket.)

Why would you want to do this? Maybe you have only one IT guy, and all system monitoring issues should be automatically assigned to him. Or, maybe you’re creating multiple notification rules so that database outages take higher priority than disk space warnings.

In most cases, you’ll probably want to set one of the following:

  • group

  • owner

  • state

  • priority

but in practice, you can set almost any attribute, including custom ones you created through the Object Manager.

Please note that the following attributes are not customizable:

  • title

  • id

  • ticket number

  • customer

  • created_by_id

  • updated_by_id

How do I know what values I can set?


😵 Invalid values → unpredictable behavior

If you provide a value that Zammad doesn’t understand (e.g., -F "priority=high"), it’s not always clear what will happen. In some cases, a ticket will be created with the default values instead - but in others, it may not be created at all!

So what values does Zammad understand, then? Well, it depends…


Use an email address or username:

-F "owner=it@chrispresso.com"
group & priority

Refer to the dropdown menus in the ticket pane:

-F "group=Users"
-F "priority=3 high"
See possible values for certain attributes in the ticket pane.


🙅 Ticket state CANNOT be set this way!

Why? Because -F "state=..." is already used as a Checkmk parameter.

Everything Else

To set any other attributes, it helps to know your way around the rails console. Valid values are those that you can set with a string:

# valid
>> Ticket.first.update(note: "You're gonna need a bigger boat")
=> true
>> Ticket.first.note
=> "You're gonna need a bigger boat"

>> Ticket::State.find_by(name: "open").id
=> 2
>> Ticket.first.update(state_id: 2)
=> true
>> Ticket.first.state.name
=> "open"

# invalid
>> Ticket.first.update(preferences: "I'm a Checkmk ticket!")
=> true
>> Ticket.first.preferences
=> {}

These values can then be passed directly to the API:

-F "note=You're gonna need a bigger boat"
-F "state_id=2"