Browser Debugger Capture
Set up the SN Utils Debug edition and ScriptSync browser debugger for approval-free screenshots, console errors, network traffic, and native dialogs.
Last updated: July 19, 2026
The Debug edition gives your ScriptSync agent a deeper browser-debugging skill set: it can read console errors, monitor network traffic and response bodies, capture full pages or individual elements, and handle native dialogs. Unlike the regular take_screenshot command, debugger screenshots do not require clicking the SN Utils extension icon for each new tab.
Why a Separate Debug Edition?
Chrome treats debugger access as a powerful permission. To keep the standard SN Utils extension's permission set minimal, the chrome.debugger permission and debugger adapter ship only in a separate build.
The regular SN Utils extension continues to support viewport screenshots after you approve the tab by clicking its extension icon. Use the Debug edition when you need automated capture or deeper diagnostics.
Set It Up
1. Install the Debug edition
Install SN Utils Debug from the Chrome Web Store →
Disable or remove the standard SN Utils extension before using the Debug edition on the same ServiceNow tab. Running two SN Utils builds together can cause duplicate scripts and inconsistent behavior.
2. Activate Pro or start a trial
Debugger automation requires an active Pro capability. If you do not already have Pro, start a 14-day free trial.
Open the Debug edition's popup afterward and confirm that your Pro, Trial, or Enterprise status is active.
3. Enable the ScriptSync debugger
In VS Code Settings, search for SN ScriptSync browser debugger and enable:
sn-scriptsync.browserDebugger.enabled
The setting is off by default because debugger attachment gives an agent access to page diagnostics and displays Chrome's debugging banner.
4. Verify the capability
Ask your AI agent to run get_capabilities, or call it through the ScriptSync Agent API. A ready setup reports:
{
"cdp": {
"available": true
},
"gates": {
"browserDebugger": true
}
}
If cdp.available is false, its reason identifies the missing requirement:
| Reason | What to do |
|---|---|
E_CDP_UNAVAILABLE | Install and use the SN Utils Debug edition |
E_PRO_REQUIRED | Activate Pro, Trial, or Enterprise in the Debug edition |
E_DISABLED | Enable sn-scriptsync.browserDebugger.enabled |
E_DEBUGGER_BUSY | Close DevTools on the target tab and retry |
When ScriptSync recognizes the Debug edition, its connection log confirms whether full-page capture, console errors, network responses, and native dialog handling are active or still need a setup step. The message also includes a personal invitation from Arnoud to share how the debugger works in your ServiceNow workflow.
What It Enables
| Command | Capability |
|---|---|
capture_full_page | Capture the viewport, an entire scrollable page, or one element selected with CSS |
start_network_capture / stop_network_capture | Record request details and response bodies while reproducing a problem |
start_console_capture / stop_console_capture | Collect console messages, log entries, and uncaught exceptions |
set_dialog_handler / clear_dialog_handler | Handle and record native alerts, confirms, prompts, and before-unload dialogs |
debugger_detach | Force the debugger to detach from the tab |
For a quick screenshot of the visible viewport, the free take_screenshot command remains available. Click the SN Utils icon on the target tab when prompted, then retry. Use capture_full_page when you want automation without that per-tab approval, the entire page, or a specific component.
Chrome's Debugging Banner
While the debugger is attached, Chrome displays an unavoidable "SN Utils started debugging this browser" banner. One-shot screenshots detach immediately, so the banner appears briefly. Network and console captures remain attached until their matching stop_* command runs.
Always stop streaming captures when finished. Use debugger_detach if a previous session left the banner open.
Security and Scope
- Debugger commands act on the browser tab selected by the local Agent API caller. Explicit tab IDs and URL patterns can target other tabs supported by the Debug edition, so only use ScriptSync with agents and tools you trust.
- ScriptSync's Agent API remains local on
127.0.0.1and requires its per-session token. - Network capture can include request and response headers, submitted data, response bodies, tokens, and other instance data. Review captured output before sharing it.
- Only one debugger can control a tab at a time; Chrome DevTools and SN Utils cannot both attach simultaneously.
See AI Agent Support for the full Agent API command reference and security model.