Kasm server allows administrators to specify images that users can provision. These images can provide a full desktop or a single application.

Default Images

Kasm Technologies maintains and publishes several default Images. The edge editions are automatically built and pushed regularly with the latest software updates and security patches. The Kasm installation will regularly pull the updated images and start using them for newly created Kasms. The following are the Kasm Technologies maintained images.

Default Kasm Images

kasmweb/desktop:1.8.0 kasmweb/desktop:1.8.0-edge

A standard desktop with minimal software. This image is open source.

DockerHub BitBucket

kasmweb/desktop-deluxe:1.8.0 kasmweb/desktop-deluxe:1.8.0-edge

A desktop with additional software such as Libre Office, Visual Studio code, and more.


kasmweb/firefox:1.8.0 kasmweb/firefox:1.8.0-edge

A firefox browser only, no desktop. This image is open source.

DockerHub BitBucket

kasmweb/chrome:1.8.0 kasmweb/chrome:1.8.0-edge

A chrome browser only, no desktop. This image is open source.

DockerHub BitBucket

kasmweb/tor-browser:1.8.0 kasmweb/tor-browser:1.8.0-edge

Tor-browser only, no desktop.


Edge Images

Kasm Technologies also publishes edge editions of the Default images that are automatically built and published nightly with the latest software and patches. Administrators may choose to use these images to always have up-to-date end-user Kasms

Custom Kasm Images

Administrators can create their own images, they must be based off kasmweb/core. See the open source project at to see the dockerfile for kasmweb/desktop and kasmweb/firefox. Pull down our code to modify kasmweb/desktop, or create your own based off kasmweb/core and then build locally.

sudo docker build -t kasmweb/desktop:custom -f dockerfile-kasm-desktop .

It is highly recommended to use a docker registry. It can be Docker Hub or a private registry. However, you can run images built locally on the server that houses the Agent role.

Guides are available for Building Custom Images and Creating Image Maintenance Processes

Add/Edit Kasm Images

From the Images menu you can edit existing images or add new images. There are a number of properties that can be defined for an image.


Image Name


Description of Image

Friendly Name

Image name shown to user

Thumbnail URL

(Optional) Address of container icon


Amount of CPU cores allocated per Image


Amount of Memory allocated per Image, in megabytes


The image is enabled for use. If unchecked the image will not be available for users to provision. Agents will not be given instructions to download Images that are disabled.

Docker Registry

The docker registry to pull the images from For Docker Hub use Leave this option blank if you intend to use local images built directly on the Agent server.

Docker Registry Username

(Optional) Username

Docker Registry Password

(Optional) Password


(Optional) hash of image

Persistent Profile Path

(Optional) Absolute path of the location to store user’s persistent profile. See Persistent Profiles for more details.

Volume Mappings

(Optional) Json data for Volume Mappings

Docker Run Config Override

(Optional) Json data for specifying additional docker run arguments, see Python Docker API for json format

Docker Exec Config

(Optional) Json data for specifying commands to executed when a Kasm is started or resumed. See the Docker Exec Config for details

Restrict Image to Docker Network

(Optional) Instances of this image will only be created on agent servers with this docker network.

Restrict Image to Kasm Agent

(Optional) Instances of this image will only be created on this agent server.

Restrict Image to Zone

(Optional) Instances of this image will only be created on Agents within the selected Deployment Zone


The Images are by default added to the all users group. This behavior can be changed with the Add Images To Default Group server setting.

Docker Exec Config

The Docker Exec configurations allow administrators to configure custom commands to be executed when a user creates or resumes a Kasm.

This JSON dictionary configuration accepts two top-level keys first_launch, and go.

  • first_launch

    This command is executed after the Kasm is launched.

  • go

    This command is executed when the user requests to create or resume a Kasm via the /go url. If the Kasm doesnt exists yet, and will be created for the first time, the first_launch command will take priority.

The following example demonstrates how to use the Docker Exex Config for the default kasmweb/chrome Image for a seamless browser isolation configuration.

See Browser Isolation for more details.

    "first_launch": {
        "cmd": "bash -c 'google-chrome --start-maximized \"$KASM_URL\"'",
        "environment": {
            "LAUNCH_URL": ""
    "go": {
        "cmd": "bash -c 'google-chrome --start-maximized \"$KASM_URL\"'"