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Debugging Service Catalog › Service Catalog › Manage service capabilities › Extend ServiceNow AI Platform capabilities
Release: Australia · Updated: 2026-03-12 · Official documentation · View source

Debug a Service Catalog variable

Monitor changes in the state and the value of a Service Catalog variable due to catalog client scripts, catalog UI policies, and catalog data lookups. You can diagnose and resolve issues related to such changes, and track client-side scripting errors on this tab.

Before you begin

Role required: admin or catalog_admin

Procedure

  1. Enable the JavaScript log and field watcher..

    1. In the banner, click the settings icon (
Image omitted: Settings.png
Settings icon\).
2.  In the System Settings window, click the **Developer** tab.

3.  Enable the **JavaScript Log and Field Watcher** option.

    The **JavaScript Log** and **Field Watcher** tabs are displayed in a pane at the bottom of the page. For information about JavaScript logs and fields watcher, see [JavaScript log](../../api-reference/scripts/c_WritingToTheDebugLog.md) and [Field Watcher](../../api-reference/scripts/c_FieldWatcher.md) .

4.  Close the System Settings window.

  1. Navigate to Service Catalog > Catalog Definitions > Maintain Items.

  2. In the Catalog Items list, select a catalog item to debug its variables, and click Try it.

  3. On the form, right-click a variable field label and select Watch Variable.

    The debug icon (

Image omitted: Debug.png
Debug icon\) is displayed next to the variable, and the **Field Watcher** tab in the bottom pane is replaced with the **Variable Watcher** tab.

  1. Edit the fields on the Variable Watcher tab.

    FieldDescription
    ItemCurrent catalog item.
    VariableVariable that is being watched.
    TypeType of the variable.
    Create rolesUser type that can create values for the variable.
    Write rolesUser type that can edit values for the variable.
    Read rolesUser type that can read values for the variable.
    ReferenceReference table for the variable. Applicable for reference variables.
    Reference QualQualifiers to restrict data that is available in the field. Applicable for list collector, lookup multiple choice, lookup select box, and reference variables.
    AttributesAttributes of the variable.
    Delete rolesUser type that can delete values for the variable.
    AllIf selected, displays the action log of the variable due to catalog client scripts, data lookups, and catalog UI policies.
    Catalog Client ScriptIf selected, displays the action log of the variable due to catalog client scripts.
    Data lookupIf selected, displays the action log of the variable due to data lookups.
    Catalog UI PolicyIf selected, displays the action log of the variable due to catalog UI policies.
Image omitted: VariableWatcherTab.png
Screenshot for the Variable Watcher tab

  1. To watch another variable, right-click that variable and select Watch Variable.

    Note: You can watch only one variable at a time.

  2. To stop watching a variable, right-click the variable and select Unwatch Variable.

  3. To clear the logs, click the Clear log icon (

Image omitted: ClearLog.png
Icon to clear log \).

  1. To resize the pane, click Small, Medium, or Large.

  2. To close the pane, click the Close icon (

Image omitted: CloseLog.png
Close icon \).

Parent Topic:Debugging Service Catalog