diff --git a/src/hooks/useControllerGrab.ts b/src/hooks/useControllerGrab.ts
index 63c8c62..b41f2de 100644
--- a/src/hooks/useControllerGrab.ts
+++ b/src/hooks/useControllerGrab.ts
@@ -1,6 +1,8 @@
 import { useRef } from 'react';
 import { useFrame, useThree } from '@react-three/fiber';
 import * as THREE from 'three';
+// DEVKIT: remove this import + the fake-input block in useFrame to strip devkit
+import { fakeInput, isFakeActive } from '@/devkit/fakeInputStore';
 
 export interface GrabState {
   /** Analog grip pressure (0..1) */
@@ -50,6 +52,26 @@ export function useControllerGrab() {
   const { gl } = useThree();
 
   useFrame((_state, _delta, frame: XRFrame | undefined) => {
+    // DEVKIT: fake-input branch — bypasses real WebXR when SimXR is active.
+    if (isFakeActive()) {
+      for (const hand of ['left', 'right'] as const) {
+        const fake = fakeInput[hand];
+        const slot = ref.current[hand];
+        slot.gripValue = fake.gripValue;
+        slot.triggerValue = fake.triggerValue;
+        slot.hasPose = fake.hasPose;
+        slot.gripWorld.copy(fake.gripWorld);
+        if (!slot.isGrabbing && fake.gripValue > GRAB_ON) {
+          slot.isGrabbing = true;
+          console.log(`[XR][grab] ▶ ${hand} START (fake v=${fake.gripValue.toFixed(2)})`);
+        } else if (slot.isGrabbing && fake.gripValue < GRAB_OFF) {
+          slot.isGrabbing = false;
+          console.log(`[XR][grab] ◼ ${hand} END (fake)`);
+        }
+      }
+      return;
+    }
+
     if (!frame) return;
     const session = frame.session;
     const referenceSpace = gl.xr.getReferenceSpace();