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Cluster Resources (Themes, Extensions, and Denylists)

Resources can be uploaded to your cluster for deployment to any Realm (deployment) in that cluster. A cluster resource is one of three types:

  • Theme — a Keycloak theme for login, account, or email UI customization. Uploaded per Keycloak major version.
  • Extension — a Keycloak server extension JAR (providers and SPI code). Uploaded per Keycloak major version.
  • Password Denylist — a Password Denylist file that is not tied to a Keycloak major version. It uses a single direct file upload and shares the extension resource limit.

Resource limits by tier

The resources available depend on your cluster tier:

TierThemesExtensions / Password Denylists
Starter1Not available — themes only
Premium11
EnterpriseUnlimitedUnlimited

Your current usage is shown next to the Resources heading (for example, 0/1 themes). On the Starter tier, only themes usage is shown, since custom extensions are not supported.

Resources Overview

Adding a resource

  1. Visit the Cluster > Config > Resources tab.

  2. Click Add New Resource. Give the resource a recognizable name (lowercase letters, numbers, hyphens, or underscores), for example theme-customer-1-0-0, and choose the resource type — Theme, Extension, or Password Denylist.

    On Starter clusters, Theme is the only available type; the Extension and Password Denylist options are shown but disabled, with a note that Starter clusters do not allow custom extensions.

    Screenshot needed

    resources-add-dialog.png — the Add a new cluster resource dialog showing the Theme / Extension / Password Denylist type selection. Include a Starter-cluster variant showing the disabled Extension and Password Denylist options with the explanatory note.

  3. After the resource is created, upload the file.

    • Themes and extensions are uploaded per Keycloak major version. Activate a specific version (for example Keycloak 26 — only major versions are supported), click the upload icon, and select your file. The file must be a .jar file. Upload it for each Keycloak version you need it available on.
    • Password Denylists use a single, cluster-wide upload and are not tied to a Keycloak major version.
    Resources Upload

Deploying resources to the cluster

After your uploads are in place, click Refresh Cluster Resources to submit the deployment request. The latest valid resources are then copied to the cluster.

Because of the way Keycloak manages themes and extensions, this requires a restart of your cluster (usually a zero-downtime operation). Phase Two staff review all resources before they are applied to a cluster to help ensure uptime and functionality.

Resources Update Cluster

Once the refresh is complete, visit your Realm (deployment) and select the theme for use. For an extension, configure it in your Realm according to how the extension operates.

Finding and filtering resources

The resources list supports searching by name and filtering by type (Themes, Extensions, Password Denylist), along with sorting and expand/collapse controls. Use these to quickly locate a resource on clusters with many entries.

Managing resources

You can disable or enable a resource using the power icon on its card to activate or deactivate it on the cluster. Disabling is a good way to temporarily remove a resource without deleting it. Use the trash icon to remove the resource entirely.

Resources Manage