JB Chrome MCP

Private skill for using Chrome DevTools MCP through mcporter.

Prerequisites

Before using this skill:

1. Open chrome://inspect/#remote-debugging in Chrome.
2. Turn remote debugging on and allow incoming debugging connections in Chrome's dialog.
3. Confirm Chrome is listening on 127.0.0.1:9222.
   • Expected listener: Server running at: 127.0.0.1:9222
   • Useful check: lsof -nP -iTCP:9222 -sTCP:LISTEN
4. Make sure mcporter is installed.

Bootstrap rule

Do not ask the user to configure mcporter manually unless the bootstrap script fails.

Before the first mcporter call, run the bundled script:

./scripts/ensure-jb-chrome-mcp.sh

The script:

• verifies Chrome is listening on 127.0.0.1:9222
• installs or updates a saved home-level mcporter server named jb-chrome-mcp
• configures chrome-devtools-mcp with --autoConnect

--autoConnect was more reliable for the chrome://inspect/#remote-debugging workflow than forcing --browserUrl http://127.0.0.1:9222.

After bootstrapping, verify the tool list if needed:

mcporter list jb-chrome-mcp --schema

Note: the first live mcporter call may trigger a Chrome permission prompt for the DevTools MCP connection. Click Allow before expecting list_pages or other live calls to return.

Preferred workflow

1. list_pages
2. select_page
3. take_snapshot before interacting
4. Use click, fill, press_key, navigate_page, or evaluate_script
5. Use diagnostics tools when needed:
   • list_console_messages
   • list_network_requests
   • get_network_request
   • performance_start_trace
   • performance_stop_trace
   • lighthouse_audit

Good defaults

• Prefer mcporter call ... --output json for machine-readable responses.
• Prefer take_snapshot over screenshots when text structure is enough.
• Call list_pages first if the active tab is unclear.
• Use select_page bringToFront=true before interactive actions when tab focus matters.

Common commands

First run:

./scripts/ensure-jb-chrome-mcp.sh

Then use the saved server.

List tabs:

mcporter call jb-chrome-mcp.list_pages --output json

Select a tab:

mcporter call jb-chrome-mcp.select_page pageId=1 bringToFront=true --output json

Take a text snapshot:

mcporter call jb-chrome-mcp.take_snapshot --output json

Click an element from the latest snapshot:

mcporter call jb-chrome-mcp.click uid=1_10 includeSnapshot=true --output json

Evaluate JavaScript:

mcporter call 'jb-chrome-mcp.evaluate_script(function: "() => document.title")' --output json

Show console messages:

mcporter call jb-chrome-mcp.list_console_messages --output json

Show network requests:

mcporter call jb-chrome-mcp.list_network_requests --output json

Start a performance trace:

mcporter call jb-chrome-mcp.performance_start_trace reload=true autoStop=true --output json

Take a screenshot:

mcporter call jb-chrome-mcp.take_screenshot fullPage=true filePath=tmp/chrome-mcp.png --output json

Fallback for explicit browser URL mode

If --autoConnect is unavailable or you are connecting to an older/manual Chrome instance that exposes /json/version, use:

mcporter config add jb-chrome-mcp \
  --stdio npx \
  --arg -y \
  --arg chrome-devtools-mcp@latest \
  --arg --browserUrl \
  --arg http://127.0.0.1:9222 \
  --arg --no-usage-statistics \
  --scope home

Troubleshooting

• If Chrome is not listening on 9222, reopen chrome://inspect/#remote-debugging and turn it on again.
• If list_pages returns a connection error, retry with the persisted config form instead of ad-hoc stdio.
• If --browserUrl fails on http://127.0.0.1:9222/json/version, switch back to --autoConnect.
• If the wrong tab is active, run list_pages and select_page again.