Inspector Workbench

The Inspector overlay is a visual product. Code that compiles is not proof. The agent must run the standalone workbench and look at screenshots after each visual change.

This skill does not replace inspector-docs. If a pane is added, renamed, or removed, load inspector-docs as well.

When To Use

Load this skill at the start of any task that changes packages/web-inspector UI, chrome, or overlay behavior.

Do not load it for docs-only Callout work. Do not load it for showcase cells. If the host app is the bug (z-index against host CSS, CopilotChat layout), use that host, then still take screenshots.

Default host

The default host is the standalone Threads state lab:

Command, from the repo root: nx run @copilotkit/web-inspector:dev:standalone
URL: http://127.0.0.1:5177/?scenario=pro-enabled-existing&reset=1
The lab mounts the real cpk-web-inspector and opens the overlay.

Do not start a showcase app, an example app, or Storybook as the default host. Those are slower and hide Inspector-only faults.

The Nx target runs Vite and the CSS watch together. Do not run Vite alone. Do not run pnpm --filter @copilotkit/web-inspector run dev. That watch serves consumers, not this lab.

Procedures

Procedure 1: Start the workbench

If the change adds, renames, or removes a pane, load inspector-docs too.
From the repo root, start nx run @copilotkit/web-inspector:dev:standalone.
Wait until http://127.0.0.1:5177 serves.
Open the browser tool this session has (Playwright MCP, Claude browser, or Codex computer use).
Go to http://127.0.0.1:5177/?scenario=pro-enabled-existing&reset=1.
If the bug is an empty, locked, error, or unread state, pick that scenario in the lab dropdown, then reload.
Wait until the overlay is open on Home or Threads. The lab clicks the launcher.
Take a baseline screenshot. Look at it before any edit.

Procedure 2: Edit, screenshot, look

Edit Inspector source under packages/web-inspector/src.
Wait for Vite to reload the lab.
If the page did not pick up the change, reload the lab URL, then wait for the overlay.
Take a screenshot of the pane that must change.
If the browser tool writes a file, write it under .inspector-workbench/<task>/. Never write a PNG at the repo root.
Look at the screenshot. If the change is not visible, the work is not done.
Repeat steps 1–6 after every visual change.
If layout or the collapsed rail is in scope, take a second screenshot at a narrow viewport.
If theme or contrast is in scope, take light and dark screenshots.

Unit tests still belong in the same change. Screenshots do not replace tests.

Procedure 3: Stop the workbench

After the Inspector task is done, stop the dev:standalone process tree.
Do not leave Vite or the CSS watch running.
Do not commit files under .inspector-workbench/.
Do not commit PNG files at the repo root.

Decision Tree

Inspector UI, chrome, overlay, launcher, or pane visuals:
- Start: Procedure 1
- While editing: Procedure 2
- After the task: Procedure 3
- If a pane is added, renamed, or removed: also load inspector-docs
Docs Callout only: stop. Load inspector-docs instead.
Bug exists only inside a host app: use that host, then still follow Procedure 2 screenshots.
Runtime or core change with no Inspector UI: this skill does not apply.

Red Flags

Signal	What it means	Do instead
Showcase, example, or Storybook is the first server	The agent skipped the workbench	Stop that server. Run Procedure 1
No screenshot after a visual edit	The agent is guessing from CSS	Take a screenshot. Look at it
PNG files at the repo root (`inspector-open.png`)	The screenshot path is wrong	Write under `.inspector-workbench/<task>/`
"The CSS looks correct, so the UI is done"	Overlay bugs do not show in source	Screenshot the lab. Fix what the image shows
Vite started without the Nx target	CSS watch is missing	Use `nx run @copilotkit/web-inspector:dev:standalone`
Port 5178 or a random port	The lab pins 5177	Free 5177. Do not pick another port
Workbench still running after the task	Watchers leak memory on this machine	Run Procedure 3
Pane added with no `inspector-docs` pass	Docs Callout will drift	Load `inspector-docs` in the same change

Error Handling

Port 5177 is in use: stop the leftover Inspector workbench on that port, then retry Procedure 1. Do not pick another port. The lab uses strictPort.
No browser tool in this session: tell the user the session cannot see Inspector. Do not guess visual results from CSS or unit tests alone.
Lab is blank or the overlay is closed: wait for boot. Then screenshot the lab console Runtime line. If Runtime is not connected, fix the lab before UI edits.
Screenshot does not show the intended change: do not claim done. Reload, screenshot again, then fix the source.
HMR did not apply a source edit: reload http://127.0.0.1:5177 with the same scenario query. Then screenshot.
Need a closed launcher or unread halo: open http://127.0.0.1:5177/?scenario=pro-enabled-existing&replay-notification=1.
Any unexpected error: halt and surface the raw error. Do not switch to a showcase app to work around the lab.

inspector-workbench