The JSS API Ruby Gem - access to the Casper Suite from Ruby

Gem Version


The jss-api gem provides a Ruby module called JSS, which is used for accessing the REST API of the JAMF Software Server (JSS), the core of the Casper Suite, an enterprise-level management tool for Apple devices from JAMF Software, LLC.

The module abstracts API resources as Ruby objects, and provides methods for interacting with those resources. It also provides some features that aren't a part of the API itself, but come with other Casper-related tools, such as uploading .pkg and .dmg JSS::Package data to the master distribution point, and the installation of JSS::Package objects on client machines. (See BEYOND THE API)

The module is not a complete implementation of the Casper API. Only some API objects are modeled, some only minimally. Of those, some are read-only, some partially writable, some fully read-write (all implemented objects can be deleted) See OBJECTS IMPLEMENTED for a list.

We've implemented the things we need in our environment, and as our needs grow, we'll add more. Hopefully others will find it useful, and add more to it as well.

Full technical documentation can be found here.


# you may need to require 'rubygems' first if you're using Ruby 1.8
require 'jss-api'   

  :user => jss_user, 
  :pw => jss_user_pw, 
  :server => jss_server_hostname

# get an array of data about all JSS::Package objects in the JSS:

# get an array of names of all JSS::Package objects in the JSS:

# Get a static computer group
mg = :name => "Macs of interest"

# Add a computer to the group
mg.add_member "pricklepants"

# save my changes

# Create a new network segment to store in the JSS
ns =
  :id => :new, 
  :name => 'Private Class C', 
  :starting_address => '', 
  :ending_address => ''

# Associate this network segment with a specific building,
# which must exist in the JSS, and be listed in JSS::Building.all_names
ns.building = "Main Office" 

# Associate this network segment with a specific software update server,
#  which must exist in the JSS, and be listed in JSS::SoftwareUpdateServer.all_names
ns.swu_server = "Main SWU Server" 

# Create the new network segment in the JSS


Connecting to the API

Before you can work with JSS Objects via the API, you have to connect to it.

The constant JSS::API contains the connection to the API (a singleton instance of JSS::APIConnection). When the JSS Module is first loaded, it isn't connected. To remedy that, use JSS::API.connect, passing it values for :user, :pw, and :server:

JSS::API.connect :user => jss_user, :pw => jss_user_pw, :server => jss_server_hostname

Make sure the user has privileges in the JSS to do things with API Objects.

The APIConnection.instance.connect method also accepts the symbols :stdin and :prompt as values for :pw, which will cause it to read the password from stdin, or prompt for it in the shell. See the JSS::APIConnection class for more connection options and details about its methods.

Also see JSS::Configuration, and the CONFIGURATION section below, for how to store server connection parameters in a simple config file.

Working with JSS Objects (a.k.a REST Resources)

All API Object classes are subclasses of JSS::APIObject and share methods for listing, retrieving, and deleting from the JSS. All supported objects can be listed, retrieved and deleted, but only some can be updated or created. Those classes do so by mixing in the JSS::Creatable and/or JSS::Updateable modules. See below for the level of implementation of each class.

Listing Objects

To get an Array of every object in the JSS of some Class, call that Class's .all method:

JSS::Computer.all # => [{:name=>"cephei", :id=>1122},{:name=>"peterparker", :id=>1218}, {:name=>"rowdy", :id=>931}, ...]

The Array will contain a Hash for each item, with at least a :name and an :id. Some classes provide more data for each item. To get just the names or just the ids in an Array, use the .all_names or .all_ids Class method

JSS::Computer.all_names # =>  ["cephei", "peterparker", "rowdy", ...]
JSS::Computer.all_ids # =>  [1122, 1218, 931, ...]

Some Classes provide other ways to list objects, depending on the data available, e.g. JSS::MobileDevice.all_udids

Retrieving Objects

To retrieve a single object call the object's constructor (.new) and provide either :name or :id or :data.

  • :name or :id will be looked up via the API
a_dept = :name => "Payroll" # =>  #<JSS::Department:0x10b4c0818...
  • :data must be the parsed JSON output of a separate API query (a hash with symbolized keys)
dept_data = JSS::API.get_rsrc("departments/name/Payroll")[:department] # => {:name=>"Payroll", :id=>42}
a_dept = :data => dept_data  # =>  #<JSS::Department:0x10b4a83f8...

Some subclasses can use more than just the :id and :name keys for lookups, e.g. computers can be looked up with :udid, :serial_number, or :mac_address.

Creating Objects

Some Objects can be created anew in the JSS. To make a new object, first instantiate one using :id => :new, and provide a unique :name.

new_pkg = :id => :new, :name => "transmogrifier-2.3-1.pkg"

Then set the attributes of the new object as needed

new_pkg.reboot_required = false
new_pkg.category = "CoolTools"
# etc..

Then use the #create method to create it in the JSS.

new_pkg.create # => 453 # the id number of the object just created

NOTE some subclasses require more data than just a :name when instantiating with :id => :new.

Updating Objects

Some objects can be modified in the JSS.

existing_script = :id => 321 = ""

After changing any attributes, use the #update method (also aliased to #save) to push the changes to the JSS.

existing_script.update # or  => true # the update was successful

Deleting Objects

To delete an object, just call its #delete method

existing_script = :id => 321
existing_script.delete # => true # the delete was successful

See JSS::APIObject, the parent class of all API resources, for general information about creating, reading, updating/saving, and deleting resources.

See the individual subclasses for any details specific to them.


See each Class's documentation for details.

Creatable and Updatable

Updatable but not Creatable

  • JSS::Computer - limited to modifying
    • name
    • barcodes
    • asset tag
    • ip address
    • location data
    • purchasing data
    • editable extension attributes
  • JSS::MobileDevice - limited to modifying
    • asset tag
    • location data
    • purchasing data
    • editable extension attributes
  • JSS::Policy - limited to modifying

NOTE Even in the API and the WebApp, Computer and Mobile Device data gathered by an Inventory Upate (a.k.a. 'recon') is not editable.


These must be created and edited via the JSS WebApp


All supported API Objects can be deleted

Other useful classes:

  • JSS::Server - An encapsulation of some info about the server, such as the JSS version and license. An instance is available as an attribute of the JSS::APIConnection singleton.
  • JSS::Client - An object representing the local machine as a Casper-managed client, and JAMF-related info and methods


The JSS::Configuration singleton class is used to read, write, and use site-specific defaults for the JSS module. When the Module is required, the single instance of JSS::Configuration is created and stored in the constant JSS::CONFIG. At that time the system-wide file /etc/jss_gem.conf is examined if it exists, and the items in it are loaded into the attributes of JSS::CONFIG. The user-specific file ~/.jss_gem.conf then is examined if it exists, and any items defined there will override those values from the system-wide file.

The values defined in those files are used as defaults throughout the module. Currently, those values are only related to establishing the API connection. For example, if a server name is defined, then a :server does not have to be specified when calling APIConnection.instance.connect. Values provided explicitly when calling JSS::API.connect will override the config values.

While the JSS::Configuration class provides methods for changing the values, saving the files, and re-reading them, or reading an arbitrary file, the files are text files with a simple format, and can be created by any means desired. The file format is one attribute per line, thus:

attr_name: value

Lines that don’t start with a known attribute name followed by a colon are ignored. If an attribute is defined more than once, the last one wins.

The currently known attributes are:

  • api_server_name [String] the hostname of the JSS API server
  • api_server_port [Integer] the port number for the API connection
  • api_verify_cert [Boolean] 'true' or 'false' - if SSL is used, should the certificate be verified? (usually false for a self-signed cert)
  • api_username [String] the JSS username for connecting to the API
  • api_timeout_open [Integer] the number of seconds for the open-connection timeout
  • api_timeout [Integer] the number of seconds for the response timeout

To put a standard server & username on all client machines, and auto-accept the JSS's self-signed https certificate, create the file /etc/jss_gem.conf containing three lines like this:

api_username: readonly-api-user
api_verify_cert: false

and then any calls to APIConnection.instance.connect will assume that server and username, and won't complain about the self-signed certificate.


The config files don't store passwords and the JSS::Configuration instance doesn't work with them. You'll have to use your own methods for acquiring the password for the JSS::API.connect call.

The APIConnection.instance.connect method also accepts the symbols :stdin# and :prompt as values for the :pw argument, which will cause it to read the password from a line of stdin, or prompt for it in the shell.

If you must store a password in a file, or retrieve it from the network, make sure it's stored securely, and that the JSS user has limited permissions.

Here's an example of how to use a password stored in a file:

password = "/path/to/secure/password/file" # read the password from a file
JSS::API.connect :pw => password   # other arguments used from the config settings

And here's an example of how to read a password from a web server and use it.

require 'open-uri'
password =  open('').read
JSS::API.connect :pw => password   # other arguments used from the config settings


While the Casper API provides access to object data in the JSS, this gem tries to use that data to provide more than just information exchange. Here are some examples of how we use the API data to provide functionality found in various Casper tools:

  • Client Machine Access
    • The JSS::Client module provides the ability to run jamf binary commands, and access the local cache of package receipts
  • Package Installation
    • JSS::Package objects can be installed on the local machine, from the appropriate distribution point
  • Script Execution
    • JSS::Script objects can be executed locally on demand
  • Package Creation
    • The JSS::Composer module provides creation of very simple .pkg and .dmg packages
    • JSS::Package objects can upload their .pkg or .dmg files to the master distribution point (JSS::Script objects can also if you store them there.)
  • Reporting/AdvancedSearch exporting
  • LDAP Access
    • JSS::LDAPServer objects can query the LDAP servers for user, group, and membership data.
  • MDM Commands
  • Extension Attributes


the JSS gem was written for:

  • Mac OS X 10.8 and higher
  • Casper Suite version 9.4 or higher
  • Casper 9.4 - 9.6 require Ruby 1.8.7 and higher
  • Casper >= 9.61 require Ruby 1.9.3 and higher

It also requires these gems, which will be installed automatically if you install JSS with gem install jss


NOTE: You may need to install XCode, and it's CLI tools, in order to install the required gems.

In general, you can install the JSS Gem with this command:

gem install jss-api

If you're using Ruby 1.8.7 (Casper 9.4 - 9.6 only), install the following gems manually first, since the JSS gem will try to install newer, incompatible versions if they aren't pre-installed.

gem install json -v 1.6.5

gem install mime-types -v 1.25.1

gem install rest-client -v 1.6.8


Copyright 2016 Pixar

Licensed under the Apache License, Version 2.0 (the "Apache License") with the following modification; you may not use this file except in compliance with the Apache License and the following modification to it:

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You may obtain a copy of the Apache License at

Unless required by applicable law or agreed to in writing, software distributed under the Apache License with the above modification is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the Apache License for the specific language governing permissions and limitations under the Apache License.