n8n Vue Flow canvas renders blank (viewport transform stuck at "none") when driven via Claude in Chrome

Summary

When n8n's workflow editor (a Vue Flow canvas) is opened and controlled via the Claude in Chrome extension, the canvas renders completely blank in screenshots — no node boxes are visible, even though the underlying DOM contains all nodes correctly and the rest of the page (sidebar, toolbar, buttons) renders fine.

Environment

• n8n Cloud instance (app.n8n.cloud)
• Reproduced on 2 different physical computers, 2 different Chrome installations, each with the Claude in Chrome extension
• Reproduced on 2 different n8n workflows (12 nodes and 21 nodes)
• Does NOT occur when the same user opens the same workflows manually in their own Chrome session without automation
• Does NOT occur in Claude's built-in Browser pane (desktop app), only in Claude in Chrome

Steps to reproduce

1. Open an n8n Cloud workflow editor URL via Claude in Chrome's navigate tool
2. Take a screenshot via the computer{action:"screenshot"} tool
3. The canvas area is blank (only the dotted background grid) — no node boxes visible, despite sidebar/toolbar/header rendering correctly

Root cause (identified via DOM inspection)

• document.querySelectorAll('[data-test-id="canvas-node"]') returns the correct number of nodes (matches the workflow's actual node count)
• Each node's getBoundingClientRect() reports large negative X coordinates (e.g. x ≈ -2360px), placing them far outside the visible viewport
• The Vue Flow viewport/pane element (.vue-flow__viewport / .vue-flow__transformationpane) has getComputedStyle(...).transform === "none" instead of the expected CSS transform matrix that normally positions nodes within the visible canvas

What we tried (did NOT fix it)

• Resizing the browser window
• Clicking n8n's "Fit to view" button
• Manually forcing a CSS transform on the viewport element via JavaScript — this did reposition the node's bounding rect, but the screenshot still rendered blank, suggesting a deeper compositing/paint issue beyond just the missing transform
• Dispatching a synthetic dblclick MouseEvent on an (off-screen) canvas node element to open its detail view — did not trigger, suggesting n8n/Vue Flow ignores untrusted/synthetic events

Impact

Prevents any visual verification or screenshot-based documentation of n8n workflows when driving the browser through Claude in Chrome. The underlying page state and data are correct — only the visual paint/compositing of the canvas is affected.