---
created: 2026-03-26T12:09:13.560Z
title: Explore /input/system/click handle probing on HMD
area: driver
files:
  - src/driver/device_provider.cpp:355
  - extern/openvr/headers/openvr_driver.h
---

## Problem

Binary analysis of `driver_lighthouse.dll` confirms the HMD creates exactly 2 input components in order: `/input/system/click` then `/proximity`. If the Phase 11.1 proximity spike proves that `UpdateBooleanComponent` works cross-driver (no ownership check on Update), the same technique could be used to trigger `/input/system/click` on the HMD.

This would let the sidecar driver simulate the system button press, which some apps may use for proximity-related behavior or other features. The handle for `/input/system/click` would be the 1st component created for device 0 (one before the `/proximity` handle).

## Solution

After the Phase 11.1 spike completes with a GO decision:
1. Use the same `probe_proximity` / `test_handle` technique to identify the `/input/system/click` handle (should be handle N-1 relative to the `/proximity` handle)
2. Test whether triggering it has useful effects in VR apps
3. If useful, integrate into the sidecar driver's command set