---
id: "593dd201-cd5a-43c0-9fa0-4ccf245d5323"
name: "Star Clicking via CDP"
micro_summary: "Stars Gmail messages with CDP mouse events using the explicit session_id; synthetic DOM events fail Gmail's trusted-event check."
status: "resolved"
see_also: []
scope: "How to star/unstar Gmail emails. All DOM-based approaches fail because Gmail checks isTrusted. Only CDP Input.dispatchMouseEvent with explicit session_id works."
---
## The Working Approach

Only CDP `Input.dispatchMouseEvent` with explicit session_id works. Gmail checks `event.isTrusted` and rejects all synthetic DOM events.

```python
sid = switch_tab(gmail_targetId)

# 1. Find and scroll to the star
js("document.querySelector('[aria-label=\"Not starred\"]').scrollIntoView({block: 'center'})")
time.sleep(0.5)

# 2. Get viewport position
pos = js("""(() => {
  const el = document.querySelector('[aria-label="Not starred"]');
  const r = el.getBoundingClientRect();
  return JSON.stringify({x: Math.round(r.left + r.width/2), y: Math.round(r.top + r.height/2)});
})()""")

# 3. Click with CDP using session_id from switch_tab
cdp("Input.dispatchMouseEvent", type="mousePressed", x=pos["x"], y=pos["y"], button="left", clickCount=1, session_id=sid)
time.sleep(0.1)
cdp("Input.dispatchMouseEvent", type="mouseReleased", x=pos["x"], y=pos["y"], button="left", clickCount=1, session_id=sid)
```

## Why Everything Else Failed

Read children for discarded probes. Root cause: Gmail's event handler checks `event.isTrusted`, which is only true for events dispatched by the browser itself (i.e., CDP Input.dispatch*). All JS-based approaches (.click, dispatchEvent, KeyboardEvent) produce `isTrusted: false`.