--- sourceDocument: Zurich API Reference sourceDocumentLink: https://www.servicenow.com/docs/r/zurich/api-reference Release : - zurich ft:locale : - en-US ft:publication_title : - Zurich API Reference ft:clusterId : - crapiref bundleId : - crapiref workflow : - Creator --- # Script Debugger # Script Debugger and Session Log {#ariaid-title1} * Release version: Zurich * * Updated July 31, 2025 * * ![](https://www.servicenow.com/docs/portal-asset/ico-clock) 3 minutes to read Summarize ![AI sparkle icon](https://servicenow.com/docs/portal-asset/ai-sparkle-icon) Summarized using AI This content was generated using new OpenAI-powered functionality. Results are provided on an as is basis and are not guaranteed to be accurate or complete. ## Summary of Script Debugger and Session Log The Script Debugger in ServiceNow enables users with thescriptdebuggerrole to debug server-side JavaScript interactively. It provides a dedicated debug transaction scoped to the current session allowing breakpoints, step-through debugging, expression evaluation, and variable inspection. The Session Log feature, accessible by users with thelogdebuggerrole, provides viewing and downloading of logs related to business rules, script includes, and custom UIs like Agent Workspace. Show full answer Show less ## Key Features * **Script Debugger capabilities for scriptdebugger role:** * Set, remove, and use breakpoints and conditional breakpoints to pause execution. * Step through code line-by-line, step into/out of functions. * View local, global, and closure variables and the call stack. * Evaluate expressions at runtime via the Console when paused. * Access the debugger from multiple interfaces: application navigator, Studio, or syntax editor. * Supports multiple developers debugging independently without interference. * Supports impersonation if the impersonated user has proper roles and access. * Does not directly support breakpoints in Scripts - Background module scripts but supports scripts called by them. * Works with domain separation, respecting domain-based data and access controls. * **Session Log capabilities for logdebugger role:** * View and download session logs in a separate tab. * Filter logs by debug options to focus on required transactions and messages. * Default limits are 100 transactions and 10,000 messages which can be configured via user preferences (`glide.debugger.log.transaction.count` and `glide.debugger.logmessageslimit`). * Logs can be displayed either under forms/lists or exclusively on the Session Log tab, configurable via the system property `glide.debugger.log.ui`. ## Important Considerations * The Script Debugger only pauses scripts running in interactive transactions where `GlideSystem.isInteractive()` returns true. * Script execution runs in interpreted mode when debugging; scripts running in strict mode may cause debugger failures. * Console statement history is cached per browser session with a configurable limit (`glide.debugger.console.cachedstmtlimit`), but is lost on cache clear or different browsers. * Debugger sessions remain open while user session is valid and close upon logout or timeout. ## Practical Benefits for ServiceNow Customers This functionality allows developers to efficiently diagnose and resolve server-side script issues in real time without impacting other users or sessions. Administrators and developers can control debugging scope and access granularly through roles and domain separation. The Session Log enhances troubleshooting by allowing selective log viewing and downloads. Overall, these tools improve script reliability and reduce time spent on debugging complex server-side code in ServiceNow environments. The Script Debugger enables users with the script_debugger role to debug server-side JavaScript. Users with the log_debugger role can use the Session Log to view and download required logs.{#script-debugger__script-debugger-rn-description} Users with the script_debugger role can perform these actions using Script Debugger: * Have a dedicated debug transaction, which applies only to the current session. * Set and remove breakpoints. * Pause the current session at a breakpoint. * Evaluate expressions during runtime. * Step through code line-by-line. * Step into and out of function and method calls. * View the value of local and global variables. * View the value of private variables from function closures. * View the call stack. * View the transaction that the system is processing. * Turn off the script debugger to resume running paused scripts. {#script-debugger__ul_fnc_tpl_bw} Use the Session Log tab to retrieve the session log for business rules, script includes, and a custom UI such as ServiceNow® Agent Workspace that has a GraphQL component. Users with the log_debugger role can: * View session logs in a separate tab. * Download a log. * View logs for Agent Workspace. * Specify debug options to view or download only the required logs. {#script-debugger__ul_bhb_vjd_khb}By default, 100 transactions and 10,000 messages appear on the Session Log tab. If the transaction or message count exceeds the default value, the session log is cleared and the next transactions or messages appear. You can configure this transaction and message count using the glide.debugger.log.transaction.count and glide.debugger.log_messages_limit user preferences respectively. For more information about the glide.debugger.log.transaction.count and glide.debugger.log_messages_limit user preferences, see [User preference settings](https://www.servicenow.com/docs/access?context=r_UserPreferenceSettings&version=zurich&pubname=zurich-platform-user-interface&ft:locale=en-US). Note: Enable Session Log as a separate tab with Script Debugger using the glide.debugger.log.ui system property. * The Page option displays logs under forms and lists and on the Session Log tab. * The Session option displays logs only on the Session Log tab. {#script-debugger__ul_xcx_kpd_khb} For more information about the glide.debugger.log.ui system property, see [Available system properties](https://www.servicenow.com/docs/access?context=r_AvailableSystemProperties&version=zurich&pubname=zurich-platform-administration&ft:locale=en-US). When you execute a statement in the Console, the executed statement is stored in the browser cache. You can use the up arrow key to get the previous statement and down arrow key to get the next statement from the browser cache. The user preference setting, glide.debugger.console.cached_stmt_limit, defines the number of statements cached in a browser session. The default statement cache value is 20 and the maximum value is 100. You can configure the statement cache value from user preferences. Note: The cached statements are not available when the browser cache is cleared or when you log in from a different browser or a different computer. The Script Debugger can pause any server-side script that runs in an interactive transaction such as business rules, script includes, script actions, or UI actions that require a response to proceed. If the GlideSystem method isInteractive() returns True when running the script in context, then the Script Debugger can pause it. Note: Some script objects, such as script includes, can be called from multiple contexts. For example: * when a business rule runs a script include on a form submit that is an interactive transaction waiting on the form data to change before continuing. * when a scheduled job runs the same script include that is a non-interactive background transaction that can also run other scripts simultaneously. {#script-debugger__ul_dqb_mk3_ckb} To debug client-side scripts, you can use browser-based developers tools. A debugger transaction remains open as long as the user session is valid. If a user logs out or their session times out, the system closes the debugger transaction. To view debug logs, see [Display debugging logs](https://www.servicenow.com/docs/76kJaIu6dR8J5RXWEq~jBA#display-debugging-logs "Display session debug logs to help diagnose script and application problems."). Note: When the Script Debugger is enabled, code is executed in interpreted mode. If parts of the script are set to run in strict mode, the debugger is not able to find the correct objects and the debugger fails. The Script Debugger must run on scripts outside of strict mode. * **[Access the Script Debugger](https://www.servicenow.com/docs/yEMhtzlUq0qbAiFw_f8mmA)** Developers can access the Script Debugger from the application navigator, Studio, or from the syntax editor. * **[Script Debugger user interface](https://www.servicenow.com/docs/LQ7gknd31JXAWFoP0plHcA)** The Script Debugger user interface (UI) displays information about breakpoints set, the call stack and line number of the currently executing script line, details about variables and transactions, and status of console. * **[Evaluate expressions in runtime using Console](https://www.servicenow.com/docs/lUDOx~xe8E2zBliumhCPpw)** Define, declare, and verify new variables and functions while you debug a script in runtime using Console. The script execution must be paused to use Console. * **[Set or remove breakpoints](https://www.servicenow.com/docs/RMb~0TkD2~8kjm0uFw3Liw)** Set breakpoints or conditional breakpoints to pause scripts at specific lines, and remove breakpoints when you are done debugging them. * **[Set or remove logpoints](https://www.servicenow.com/docs/CijaOenjMG4ZenfhH82vLw)** Set breakpoints or conditional logpoints to log messages to the console at specific lines, and remove logpoints when you are done debugging them. * **[Script Debugger multiple developer support](https://www.servicenow.com/docs/lInnxmwO1YyMerC8OM65Hw)** The Script Debugger allows multiple developers to debug their own transactions without affecting each other. * **[Script Debugger impersonation support](https://www.servicenow.com/docs/A~VLuq~gjeY3Tm6OOv5oCQ)** You can use the Script Debugger while impersonating another user, but only if the impersonated user has the script_debugger role and has read access to the target script. * **[Script Debugger Scripts - Background support](https://www.servicenow.com/docs/OhoPBlF_bQk44M_IMy509A)** The Scripts - Background module does not support setting breakpoints directly in the script field. You can however, set breakpoints in the script objects called or triggered by the Scripts - Background module. * **[Domain separation and Script Debugger](https://www.servicenow.com/docs/7y6C6MusvHXUr4giANMUtQ)** Domain separation is supported in Script Debugger. Domain separation enables you to separate data, processes, and administrative tasks into logical groupings called domains. You can control several aspects of this separation, including which users can see and access data.