diff --git a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+AXSnapshotFallback.swift b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+AXSnapshotFallback.swift
index 13244aeaf2..df933a24ab 100644
--- a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+AXSnapshotFallback.swift
+++ b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+AXSnapshotFallback.swift
@@ -217,12 +217,11 @@ extension RunnerTests {
       }
 
       let rootFrame = privateAXRect(root["frame"])
-      let geometry = privateAXSnapshotGeometry(
+      let viewport = privateAXSnapshotViewport(
         app: app,
         bundleId: target.bundleId,
         rootFrame: rootFrame
       )
-      let viewport = geometry.viewport
       let nodes = privateAXAcquisition(
         rawRoot: root,
         hint: hint
@@ -259,8 +258,7 @@ extension RunnerTests {
         customActions: Self.privateAXCustomActionCoverage(
           response[RunnerAXSnapshotCustomActionsKey]
         ),
-        viewport: viewport,
-        interfaceOrientation: geometry.interfaceOrientation
+        viewport: viewport
       )
     #else
       return nil
@@ -275,37 +273,32 @@ extension RunnerTests {
     !hasAbandonedMainThreadWork() && !isSnapshotXCTestChannelPenalized(bundleId: bundleId)
   }
 
-  /// The geometry this tier may anchor a rotation on. The bridge's own root frame is one more
-  /// reported box rather than the app's frame, so a capture anchored on it reports no interface
-  /// orientation and normalizes nothing: rotated system surfaces then stay as reported, which the
-  /// consumers already treat as geometry they cannot measure (#2612).
-  private func privateAXSnapshotGeometry(
+  /// The app's reported viewport when XCTest can read it, else the bridge's own root frame declared
+  /// `.derived`, which cannot anchor a rotation: rotated system surfaces then stay as reported (#2612).
+  private func privateAXSnapshotViewport(
     app: XCUIApplication,
     bundleId: String?,
     rootFrame: CGRect
-  ) -> (viewport: CGRect, interfaceOrientation: Int) {
-    let fallback = rootFrame.isEmpty ? CGRect.infinite : rootFrame
+  ) -> SnapshotViewport {
+    let fallback = SnapshotViewport.derived(box: rootFrame)
     guard shouldReadPrivateAXViewportViaXCTest(bundleId: bundleId) else {
-      return (fallback, RunnerInterfaceOrientation.unknown)
+      return fallback
     }
     do {
-      let anchor = try runMainThreadWork(
+      let reported = try runMainThreadWork(
         "private_ax_viewport",
         timeout: 1,
         timeoutError: snapshotMainThreadTimeoutError("reading private AX viewport")
       ) {
-        (
-          viewport: self.safeSnapshotViewport(app: app),
-          interfaceOrientation: self.capturedInterfaceOrientation(app: app)
-        )
+        self.safeSnapshotViewport(app: app, readingOrientation: true)
       }
-      if anchor.viewport.isInfinite || anchor.viewport.isNull || anchor.viewport.isEmpty {
-        return (fallback, RunnerInterfaceOrientation.unknown)
+      if case .missing = reported {
+        return fallback
       }
-      return (anchor.viewport, anchor.interfaceOrientation)
+      return reported
     } catch {
       NSLog("AGENT_DEVICE_RUNNER_PRIVATE_AX_VIEWPORT_FALLBACK=%@", String(describing: error))
-      return (fallback, RunnerInterfaceOrientation.unknown)
+      return fallback
     }
   }
 
diff --git a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+Navigation.swift b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+Navigation.swift
index da185b037e..3ab477ff74 100644
--- a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+Navigation.swift
+++ b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+Navigation.swift
@@ -1,3 +1,4 @@
+import AgentDeviceSnapshotPresentation
 import XCTest
 
 extension RunnerTests {
@@ -120,16 +121,9 @@ extension RunnerTests {
     return navigationBackKeywords.firstIndex { text.contains($0) }
   }
 
-  // isFinite/>0 alone don't reject CGRect.infinite — its origin (~-9e307) is finite.
-  static func isUsableNavigationFrame(_ frame: CGRect) -> Bool {
-    guard frame.width.isFinite, frame.height.isFinite, frame.width > 0, frame.height > 0 else {
-      return false
-    }
-    return !frame.isInfinite
-  }
-
   static func isTopNavigationControlFrame(_ candidate: CGRect, in window: CGRect) -> Bool {
-    guard isUsableNavigationFrame(candidate), isUsableNavigationFrame(window) else {
+    guard SnapshotGeometry.isPositiveFinite(candidate), SnapshotGeometry.isPositiveFinite(window)
+    else {
       return false
     }
     // Accept the compact navigation/search header band without matching deep content controls.
@@ -138,7 +132,7 @@ extension RunnerTests {
   }
 
   static func topLeadingNavigationFallbackPoint(in frame: CGRect) -> CGPoint? {
-    guard isUsableNavigationFrame(frame) else {
+    guard SnapshotGeometry.isPositiveFinite(frame) else {
       return nil
     }
     // Aim at the standard leading navigation slot, bounded for compact and tablet widths.
diff --git a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+Snapshot.swift b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+Snapshot.swift
index 3d469bf868..f87b5b0648 100644
--- a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+Snapshot.swift
+++ b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+Snapshot.swift
@@ -21,9 +21,8 @@ extension RunnerTests {
   struct SnapshotTraversalContext {
     let queryRoot: XCUIElement
     let rootSnapshot: XCUIElementSnapshot
-    let viewport: CGRect
-    /** Which way the app's interface is turned from the device's native space (#2612). */
-    let interfaceOrientation: Int
+    /** Carries which way the app's interface is turned from the device's native space (#2612). */
+    let viewport: SnapshotViewport
     /**
      * The keyboard band this capture measured, published beside the tree so the daemon's tap guard
      * measures against the producer's own reading rather than a band it derives from these rects
@@ -278,8 +277,7 @@ extension RunnerTests {
       nodes: nodes,
       truncated: false,
       effectiveDepth: nil,
-      viewport: context.viewport,
-      interfaceOrientation: context.interfaceOrientation
+      viewport: context.viewport
     )
   }
 
@@ -435,8 +433,7 @@ extension RunnerTests {
       nodes: nodes,
       truncated: false,
       effectiveDepth: nil,
-      viewport: context.viewport,
-      interfaceOrientation: context.interfaceOrientation
+      viewport: context.viewport
     )
   }
 
@@ -455,14 +452,13 @@ extension RunnerTests {
           nodes: nodes,
           truncated: false,
           effectiveDepth: nil,
-          viewport: .infinite,
-          interfaceOrientation: RunnerInterfaceOrientation.unknown
+          viewport: .missing(reason: .notProvided)
         ),
         .completed
       )
     }
 
-    let viewport = safeSnapshotViewport(app: app)
+    let viewport = safeSnapshotViewport(app: app, readingOrientation: false)
     var seen = Set<String>()
     var candidates: [RawAXNode] = []
     let flatElements = flatInteractiveElements(app: app, deadline: deadline)
@@ -492,11 +488,9 @@ extension RunnerTests {
     }
 
     // The synthetic root doubles as the daemon's viewport (find.ts prefers on-screen matches
-    // inside nodes[0].rect): use the real screen viewport when capture produced a finite one,
-    // so off-screen candidates can never inflate the root and masquerade as on-screen.
-    let rootRect = viewport.isInfinite || viewport.isNull || viewport.isEmpty
-      ? interactiveRootFrame(for: candidates)
-      : viewport
+    // inside nodes[0].rect): use the real screen viewport when the capture resolved one, so
+    // off-screen candidates can never inflate the root and masquerade as on-screen.
+    let rootRect = viewport.rect ?? interactiveRootFrame(for: candidates)
     nodes[0] = interactiveRootNode(rect: rootRect)
     for candidate in candidates {
       nodes.append(
@@ -524,8 +518,7 @@ extension RunnerTests {
         nodes: nodes,
         truncated: outcome == .deadlineExhausted,
         effectiveDepth: nil,
-        viewport: viewport,
-        interfaceOrientation: RunnerInterfaceOrientation.unknown
+        viewport: viewport
       ),
       outcome
     )
diff --git a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+SnapshotAcquisition.swift b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+SnapshotAcquisition.swift
index 26572f56fa..7ebc82596f 100644
--- a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+SnapshotAcquisition.swift
+++ b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+SnapshotAcquisition.swift
@@ -41,18 +41,13 @@ extension RunnerTests {
     // The viewport and the interface orientation are one hop: geometry that arrives in the device's
     // native space can only be placed relative to the app's own frame and rotation, and asking for
     // the pair twice would read them at two different moments of a rotation.
-    let geometry = try runMainThreadWork(
+    let viewport = try runMainThreadWork(
       "snapshot_viewport",
       timeout: min(1.0, max(0.1, captureDeadline.timeIntervalSinceNow)),
       timeoutError: snapshotMainThreadTimeoutError("preparing tree snapshot")
     ) {
-      (
-        viewport: self.safeSnapshotViewport(app: app),
-        interfaceOrientation: self.capturedInterfaceOrientation(app: app)
-      )
+      self.safeSnapshotViewport(app: app, readingOrientation: true)
     }
-    let viewport = geometry.viewport
-    let interfaceOrientation = geometry.interfaceOrientation
     let treeSliceBudget = treeCaptureSliceBudgetOverride ?? treeCaptureSliceBudget
     let slice = min(treeSliceBudget, max(0.5, captureDeadline.timeIntervalSinceNow))
     guard let rootSnapshot = try captureSnapshotRootBounded(app, sliceSeconds: slice) else {
@@ -70,7 +65,6 @@ extension RunnerTests {
       queryRoot: app,
       rootSnapshot: rootSnapshot,
       viewport: viewport,
-      interfaceOrientation: interfaceOrientation,
       keyboardBand: keyboardBand
     )
   }
@@ -140,8 +134,18 @@ extension RunnerTests {
     return nil
   }
 
-  func safeSnapshotViewport(app: XCUIApplication) -> CGRect {
-    safely("SNAPSHOT_VIEWPORT", CGRect.infinite) { snapshotViewport(app: app) }
+  /// The viewport as a declared fact; a read that raises is `.missing(reason: .notProvided)` (#2891).
+  /// `readingOrientation` reads the interface orientation in the same hop, for tiers whose frames can
+  /// arrive in the device's native space; without it the viewport cannot anchor a rotation.
+  func safeSnapshotViewport(app: XCUIApplication, readingOrientation: Bool) -> SnapshotViewport {
+    safely("SNAPSHOT_VIEWPORT", .missing(reason: .notProvided)) {
+      .reported(
+        box: snapshotAppFrame(app: app),
+        interfaceOrientation: readingOrientation
+          ? capturedInterfaceOrientation(app: app)
+          : RunnerInterfaceOrientation.unknown
+      )
+    }
   }
 
   private func describeSnapshotError(_ error: Error) -> String {
@@ -231,16 +235,12 @@ extension RunnerTests {
     return text.isEmpty ? nil : text
   }
 
-  private func snapshotViewport(app: XCUIApplication) -> CGRect {
+  private func snapshotAppFrame(app: XCUIApplication) -> CGRect {
 #if os(iOS)
-    let appFrame = onScreenWindowFrame(app: app)
+    return onScreenWindowFrame(app: app)
 #else
-    let appFrame = app.frame
+    return app.frame
 #endif
-    if !appFrame.isNull && !appFrame.isEmpty {
-      return appFrame
-    }
-    return .infinite
   }
 
   static func snapshotTraversalIdentity(
diff --git a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+SnapshotCapturePlan.swift b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+SnapshotCapturePlan.swift
index e7f3898652..f1547821ba 100644
--- a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+SnapshotCapturePlan.swift
+++ b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+SnapshotCapturePlan.swift
@@ -513,8 +513,7 @@ extension RunnerTests {
     let normalizedAcquisition = acquisition.replacingNodes(
       SnapshotGeometrySpace.normalized(
         nodes: acquisition.nodes,
-        viewport: acquisition.viewport,
-        interfaceOrientation: acquisition.interfaceOrientation
+        viewport: acquisition.viewport
       )
     )
 
@@ -641,7 +640,7 @@ extension RunnerTests {
       guard Self.structuralOnlyNodeTypes.contains(node.type) else { return false }
       guard !isRootContainer else { return true }
 
-      let isFullScreenContainer = !node.hittable && rootRects.contains { rootRect in
+      let isFullScreenContainer = node.hittable != true && rootRects.contains { rootRect in
         rootRect.x == node.rect.x && rootRect.y == node.rect.y
           && rootRect.width == node.rect.width && rootRect.height == node.rect.height
       }
diff --git a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+AXSnapshotFallbackTests.swift b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+AXSnapshotFallbackTests.swift
index 82f6bec10b..4e4fd9ff44 100644
--- a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+AXSnapshotFallbackTests.swift
+++ b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+AXSnapshotFallbackTests.swift
@@ -464,15 +464,14 @@ extension RunnerTests {
       interactiveOnly: true, customActions: false)
     let acquired = SnapshotGeometrySpace.normalized(
       nodes: privateAXAcquisition(rawRoot: tree, hint: hint),
-      viewport: viewport,
-      interfaceOrientation: RunnerInterfaceOrientation.portrait
+      viewport: .reported(box: viewport, interfaceOrientation: RunnerInterfaceOrientation.portrait)
     )
     // Acquisition serializes the drawer too; the shared fold is what hides it (#1797).
     XCTAssertTrue(acquired.compactMap(\.label).contains("Admin settings"))
 
     let capture = try SnapshotPresentation.presentRegular(
       SnapshotAcquisition(
-        hint: hint, nodes: acquired, truncated: false, effectiveDepth: nil, viewport: viewport),
+        hint: hint, nodes: acquired, truncated: false, effectiveDepth: nil, viewport: .reported(box: viewport)),
       options: PresentationOptions(interactiveOnly: true, depth: nil, scope: nil, raw: false),
       policy: .cursorProjected
     )
diff --git a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+PrivateAXPresentationTests.swift b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+PrivateAXPresentationTests.swift
index 23ee5db993..3dcd2908dd 100644
--- a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+PrivateAXPresentationTests.swift
+++ b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+PrivateAXPresentationTests.swift
@@ -42,8 +42,11 @@ extension RunnerTests {
       interfaceOrientation: RunnerInterfaceOrientation.portrait)
     return try SnapshotPresentation.presentRegular(
       SnapshotAcquisition(
-        hint: hint, nodes: nodes, truncated: false, effectiveDepth: nil, viewport: viewport,
-        interfaceOrientation: RunnerInterfaceOrientation.portrait),
+        hint: hint, nodes: nodes, truncated: false, effectiveDepth: nil,
+        viewport: .reported(
+          box: viewport,
+          interfaceOrientation: RunnerInterfaceOrientation.portrait
+        )),
       options: PresentationOptions(
         interactiveOnly: interactiveOnly, depth: nil, scope: nil, raw: false),
       policy: .cursorProjected
@@ -59,8 +62,7 @@ extension RunnerTests {
   ) -> [RawAXNode] {
     SnapshotGeometrySpace.normalized(
       nodes: privateAXAcquisition(rawRoot: rawRoot, hint: hint),
-      viewport: viewport,
-      interfaceOrientation: interfaceOrientation
+      viewport: .reported(box: viewport, interfaceOrientation: interfaceOrientation)
     )
   }
 
diff --git a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotCapturePlanOccupancyTests.swift b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotCapturePlanOccupancyTests.swift
index edec6e8333..7f12cb87b6 100644
--- a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotCapturePlanOccupancyTests.swift
+++ b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotCapturePlanOccupancyTests.swift
@@ -94,8 +94,7 @@ extension RunnerTests {
     XCTAssertFalse(app.frame.isEmpty)
     // The traversal context reads the viewport under a 1 s cap; a cold first read can overrun it
     // and abandon the wrong block, so pay it here, uncapped.
-    _ = safeSnapshotViewport(app: app)
-    _ = capturedInterfaceOrientation(app: app)
+    _ = safeSnapshotViewport(app: app, readingOrientation: true)
     currentApp = app
     currentBundleId = "com.callstack.agentdevice.runner.tree-capture-test"
     snapshotXCTestPenaltyWarmupExemption.isPending = true
diff --git a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotCapturePlanTests.swift b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotCapturePlanTests.swift
index a2c709eeb9..87d3ad061e 100644
--- a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotCapturePlanTests.swift
+++ b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotCapturePlanTests.swift
@@ -282,7 +282,7 @@ extension RunnerTests {
         nodes: [],
         truncated: false,
         effectiveDepth: nil,
-        viewport: .infinite
+        viewport: .reported(box: CGRect(x: 0, y: 0, width: 402, height: 874))
       ),
       options: options
     )
diff --git a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotHittabilityTests.swift b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotHittabilityTests.swift
index 61e0024121..89828f62f7 100644
--- a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotHittabilityTests.swift
+++ b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotHittabilityTests.swift
@@ -97,7 +97,7 @@ extension RunnerTests {
         nodes: nodes,
         truncated: false,
         effectiveDepth: nil,
-        viewport: CGRect(x: 0, y: 0, width: 100, height: 100)
+        viewport: .reported(box: CGRect(x: 0, y: 0, width: 100, height: 100))
       ),
       options: options
     )
diff --git a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotPresentationConformanceTests.swift b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotPresentationConformanceTests.swift
index 718eb5651f..2c16b49851 100644
--- a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotPresentationConformanceTests.swift
+++ b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotPresentationConformanceTests.swift
@@ -97,7 +97,7 @@ extension RunnerTests {
         },
         truncated: false,
         effectiveDepth: nil,
-        viewport: fixture.viewport.cgRect
+        viewport: .reported(box: fixture.viewport.cgRect)
       )
       let options = PresentationOptions(
         interactiveOnly: false,
diff --git a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotPresentationGeometryTests.swift b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotPresentationGeometryTests.swift
index 087f00e510..db52ad5d2f 100644
--- a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotPresentationGeometryTests.swift
+++ b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotPresentationGeometryTests.swift
@@ -6,7 +6,7 @@ extension RunnerTests {
   func testEffectiveGeometryIntersectsViewportAndAncestorClip() {
     let effective = SnapshotGeometry.effectiveFrame(
       reportedFrame: CGRect(x: 350, y: 80, width: 100, height: 100),
-      viewport: CGRect(x: 0, y: 0, width: 402, height: 874),
+      viewport: .reported(box: CGRect(x: 0, y: 0, width: 402, height: 874)),
       ancestorClip: CGRect(x: 300, y: 100, width: 80, height: 80)
     )
 
@@ -17,7 +17,7 @@ extension RunnerTests {
     let reported = CGRect(x: 500, y: 120, width: 100, height: 44)
     let effective = SnapshotGeometry.effectiveFrame(
       reportedFrame: reported,
-      viewport: CGRect(x: 0, y: 0, width: 402, height: 874),
+      viewport: .reported(box: CGRect(x: 0, y: 0, width: 402, height: 874)),
       ancestorClip: nil
     )
 
diff --git a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotPresentationInvariantTests.swift b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotPresentationInvariantTests.swift
index c0c739b86d..9aeea4f490 100644
--- a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotPresentationInvariantTests.swift
+++ b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotPresentationInvariantTests.swift
@@ -97,7 +97,7 @@ extension RunnerTests {
       nodes: nodes,
       truncated: false,
       effectiveDepth: nil,
-      viewport: viewport
+      viewport: .reported(box: viewport)
     )
   }
 
@@ -147,7 +147,7 @@ extension RunnerTests {
       ],
       truncated: false,
       effectiveDepth: nil,
-      viewport: CGRect(x: 0, y: 0, width: 320, height: 240)
+      viewport: .reported(box: CGRect(x: 0, y: 0, width: 320, height: 240))
     )
 
     let options = PresentationOptions(
@@ -203,7 +203,7 @@ extension RunnerTests {
       ],
       truncated: false,
       effectiveDepth: nil,
-      viewport: CGRect(x: 0, y: 0, width: 320, height: 240)
+      viewport: .reported(box: CGRect(x: 0, y: 0, width: 320, height: 240))
     )
 
     let options = PresentationOptions(
@@ -254,7 +254,7 @@ extension RunnerTests {
           nodes: nodes,
           truncated: false,
           effectiveDepth: nil,
-          viewport: .infinite
+          viewport: .reported(box: CGRect(x: 0, y: 0, width: 100, height: 100))
         ),
         options: options
       ).nodes)
@@ -309,7 +309,7 @@ extension RunnerTests {
     XCTAssertThrowsError(
       try SnapshotPresentationInvariant.validateRegular(
         folded,
-        viewport: viewport,
+        viewport: .reported(box: viewport),
         policy: .cursorProjected
       )
     ) { error in
diff --git a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotPresentationTests.swift b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotPresentationTests.swift
index c103678186..855abbd25b 100644
--- a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotPresentationTests.swift
+++ b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotPresentationTests.swift
@@ -40,7 +40,7 @@ extension RunnerTests {
           truncated: 0,
           blocked: false
         ),
-        viewport: .infinite
+        viewport: .reported(box: CGRect(x: 0, y: 0, width: 100, height: 100))
       ),
       options: PresentationOptions(
         interactiveOnly: true,
@@ -113,7 +113,7 @@ extension RunnerTests {
             projection: .regular, depth: nil, regularPresentedDepth: nil,
             interactiveOnly: false, customActions: false),
           nodes: acquired, truncated: false, effectiveDepth: nil,
-          viewport: CGRect(x: 0, y: 0, width: 1_000, height: 1_000)),
+          viewport: .reported(box: CGRect(x: 0, y: 0, width: 1_000, height: 1_000))),
         options: PresentationOptions(interactiveOnly: false, depth: nil, scope: nil, raw: false)
       ).nodes
     )
@@ -124,7 +124,7 @@ extension RunnerTests {
             projection: .regular, depth: nil, regularPresentedDepth: nil,
             interactiveOnly: true, customActions: false),
           nodes: acquired, truncated: false, effectiveDepth: nil,
-          viewport: CGRect(x: 0, y: 0, width: 1_000, height: 1_000)),
+          viewport: .reported(box: CGRect(x: 0, y: 0, width: 1_000, height: 1_000))),
         options: PresentationOptions(interactiveOnly: true, depth: nil, scope: nil, raw: false)
       ).nodes
     )
@@ -147,7 +147,8 @@ extension RunnerTests {
           hint: CaptureHint(
             projection: .raw, depth: nil, regularPresentedDepth: nil,
             interactiveOnly: false, customActions: false),
-          nodes: acquired, truncated: false, effectiveDepth: nil, viewport: .infinite),
+          nodes: acquired, truncated: false, effectiveDepth: nil,
+          viewport: .reported(box: CGRect(x: 0, y: 0, width: 1_000, height: 1_000)) ),
         options: PresentationOptions(interactiveOnly: true, depth: nil, scope: nil, raw: true)
       ).nodes
     )
@@ -176,7 +177,7 @@ extension RunnerTests {
       nodes: nodes,
       truncated: false,
       effectiveDepth: nil,
-      viewport: CGRect(x: 0, y: 0, width: 100, height: 100)
+      viewport: .reported(box: CGRect(x: 0, y: 0, width: 100, height: 100))
     )
 
     let presented = try SnapshotPresentation.presentRegular(
@@ -211,7 +212,7 @@ extension RunnerTests {
           nodes: acquired,
           truncated: false,
           effectiveDepth: nil,
-          viewport: viewport
+          viewport: .reported(box: viewport)
         ),
         options: regularOptions
       ).nodes
@@ -231,7 +232,7 @@ extension RunnerTests {
           nodes: acquired,
           truncated: false,
           effectiveDepth: nil,
-          viewport: .infinite
+          viewport: .reported(box: CGRect(x: 0, y: 0, width: 100, height: 100))
         ),
         options: rawOptions
       ).nodes
@@ -286,7 +287,7 @@ extension RunnerTests {
       ],
       truncated: false,
       effectiveDepth: nil,
-      viewport: CGRect(x: 0, y: 0, width: 1_000, height: 1_000)
+      viewport: .reported(box: CGRect(x: 0, y: 0, width: 1_000, height: 1_000))
     )
     let options = PresentationOptions(
       interactiveOnly: true,
@@ -313,7 +314,7 @@ extension RunnerTests {
           nodes: acquisition.nodes,
           truncated: false,
           effectiveDepth: nil,
-          viewport: .infinite
+          viewport: .reported(box: CGRect(x: 0, y: 0, width: 100, height: 100))
         ),
         options: PresentationOptions(
           interactiveOnly: true,
@@ -374,10 +375,11 @@ extension RunnerTests {
     let regularAcquisition = SnapshotAcquisition(
       hint: SnapshotPresentation.captureHint(for: regularRequest),
       nodes: nodes, truncated: false, effectiveDepth: nil,
-      viewport: CGRect(x: 0, y: 0, width: 100, height: 100))
+      viewport: .reported(box: CGRect(x: 0, y: 0, width: 100, height: 100)))
     let rawAcquisition = SnapshotAcquisition(
       hint: SnapshotPresentation.captureHint(for: rawRequest),
-      nodes: nodes, truncated: false, effectiveDepth: nil, viewport: .infinite)
+      nodes: nodes, truncated: false, effectiveDepth: nil,
+      viewport: .reported(box: CGRect(x: 0, y: 0, width: 100, height: 100)))
 
     let regularCaptureForRawRequest = try SnapshotPresentation.present(
       regularAcquisition, options: rawRequest)
@@ -470,7 +472,7 @@ extension RunnerTests {
           ],
           truncated: false,
           effectiveDepth: nil,
-          viewport: CGRect(x: 0, y: 0, width: 100, height: 100)
+          viewport: .reported(box: CGRect(x: 0, y: 0, width: 100, height: 100))
         ),
         options: options
       )
@@ -552,7 +554,7 @@ extension RunnerTests {
       nodes: nodes,
       truncated: false,
       effectiveDepth: nil,
-      viewport: viewport
+      viewport: .reported(box: viewport)
     )
     let presented = try XCTUnwrap(
       SnapshotPresentation.present(acquisition, options: options)?.nodes)
@@ -596,8 +598,10 @@ extension RunnerTests {
     ]
     let normalized = SnapshotGeometrySpace.normalized(
       nodes: acquired,
-      viewport: viewport,
-      interfaceOrientation: RunnerInterfaceOrientation.landscapeRight
+      viewport: .reported(
+        box: viewport,
+        interfaceOrientation: RunnerInterfaceOrientation.landscapeRight
+      )
     )
     let options = PresentationOptions(interactiveOnly: false, depth: 3, scope: nil, raw: false)
     let hint = SnapshotPresentation.captureHint(for: options)
@@ -608,7 +612,7 @@ extension RunnerTests {
           nodes: normalized,
           truncated: false,
           effectiveDepth: nil,
-          viewport: viewport
+          viewport: .reported(box: viewport)
         ),
         options: options
       )?.nodes
diff --git a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotVisibilityFoldTests.swift b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotVisibilityFoldTests.swift
index 2063c56f14..ee6c4400dd 100644
--- a/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotVisibilityFoldTests.swift
+++ b/apple/runner/AgentDeviceRunner/AgentDeviceRunnerUITests/UnitTests/RunnerTests+SnapshotVisibilityFoldTests.swift
@@ -25,7 +25,11 @@ extension RunnerTests {
     policy: SnapshotVisibilityFold.Policy = .cursorProjected
   ) -> [SnapshotPresentationNode] {
     SnapshotVisibilityFold.fold(
-      nodes, viewport: viewport, interactiveOnly: interactiveOnly, policy: policy)
+      nodes,
+      viewport: .reported(box: viewport),
+      interactiveOnly: interactiveOnly,
+      policy: policy
+    )
   }
 
   func testRegularFoldClipsScrollOverflowReparentsAndBooksHints() {
diff --git a/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotCoordinateSpace.swift b/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotCoordinateSpace.swift
index 561861bc29..300b8c910e 100644
--- a/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotCoordinateSpace.swift
+++ b/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotCoordinateSpace.swift
@@ -105,7 +105,7 @@ public enum CoordinateSpaceRotation {
 
 public enum SnapshotGeometrySpace: Equatable {
   case appOrientation
-  case deviceNative(appFrame: CGRect, interfaceOrientation: Int)
+  case deviceNative(appFrame: SnapshotViewport.Box, interfaceOrientation: Int)
 
   public static let quarterTurnTolerance: Double = 1
 
@@ -116,22 +116,26 @@ public enum SnapshotGeometrySpace: Equatable {
     case .deviceNative(let appFrame, let interfaceOrientation):
       return CoordinateSpaceRotation.oriented(
         rect: reportedFrame,
-        in: appFrame,
+        in: appFrame.rect,
         interfaceOrientation: interfaceOrientation
       )
     }
   }
 
+  /// Only a `.reported` viewport carries an orientation, so only it can anchor a rotation.
   public static func space(
     reportedBySurfaceHost isSurfaceHost: Bool,
     reportedFrame: CGRect,
     inheritedFrom inherited: SnapshotGeometrySpace,
-    appFrame: CGRect,
-    interfaceOrientation: Int
+    viewport: SnapshotViewport
   ) -> SnapshotGeometrySpace {
     guard isSurfaceHost else { return inherited }
-    guard namesQuarterTurn(interfaceOrientation) else { return .appOrientation }
-    guard isQuarterTurned(reportedFrame, relativeTo: appFrame) else { return .appOrientation }
+    guard case .reported(let appFrame, let interfaceOrientation) = viewport,
+      namesQuarterTurn(interfaceOrientation),
+      isQuarterTurned(reportedFrame, relativeTo: appFrame.rect)
+    else {
+      return .appOrientation
+    }
     return .deviceNative(appFrame: appFrame, interfaceOrientation: interfaceOrientation)
   }
 
@@ -145,7 +149,7 @@ public enum SnapshotGeometrySpace: Equatable {
   }
 
   private static func isQuarterTurned(_ frame: CGRect, relativeTo appFrame: CGRect) -> Bool {
-    guard isPlottable(frame), isPlottable(appFrame),
+    guard SnapshotGeometry.isPositiveFinite(frame),
       abs(appFrame.width - appFrame.height) > quarterTurnTolerance
     else {
       return false
@@ -153,19 +157,12 @@ public enum SnapshotGeometrySpace: Equatable {
     return abs(frame.width - appFrame.height) <= quarterTurnTolerance
       && abs(frame.height - appFrame.width) <= quarterTurnTolerance
   }
-
-  private static func isPlottable(_ frame: CGRect) -> Bool {
-    frame.origin.x.isFinite && frame.origin.y.isFinite
-      && frame.width.isFinite && frame.height.isFinite
-      && frame.width > 0 && frame.height > 0
-  }
 }
 
 extension SnapshotGeometrySpace {
   public static func normalized(
     nodes: [RawAXNode],
-    viewport: CGRect,
-    interfaceOrientation: Int
+    viewport: SnapshotViewport
   ) -> [RawAXNode] {
     let carriers = SnapshotVisibilityFold.visibilityExemptCarrierTypes
     var spaces = [SnapshotGeometrySpace](repeating: .appOrientation, count: nodes.count)
@@ -180,16 +177,16 @@ extension SnapshotGeometrySpace {
         ),
         reportedFrame: node.rect.cgRect,
         inheritedFrom: parentIndex.map { spaces[$0] } ?? .appOrientation,
-        appFrame: viewport,
-        interfaceOrientation: interfaceOrientation
+        viewport: viewport
       )
       spaces[position] = nodeSpace
       let frame = nodeSpace.orientedFrame(of: node.rect.cgRect)
       result.append(
         node.replacing(
           rect: SnapshotRect(frame),
-          hittable: node.parentIndex != nil
-            && SnapshotGeometry.isGeometricallyActionable(
+          hittable: node.parentIndex == nil
+            ? false
+            : SnapshotGeometry.isGeometricallyActionable(
               enabled: node.enabled,
               frame: frame,
               viewport: viewport
diff --git a/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotGeometry.swift b/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotGeometry.swift
index ec8bc50863..d0db9a8e24 100644
--- a/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotGeometry.swift
+++ b/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotGeometry.swift
@@ -2,14 +2,23 @@ import Foundation
 import CoreGraphics
 
 public enum SnapshotGeometry {
+  /// Twin of `isPositiveFiniteRect` in `packages/kernel/src/rect.ts`. `CGRect.infinite` is built
+  /// from finite components, so it is refused by identity.
+  public static func isPositiveFinite(_ rect: CGRect) -> Bool {
+    !rect.isInfinite
+      && rect.origin.x.isFinite && rect.origin.y.isFinite
+      && rect.size.width.isFinite && rect.size.height.isFinite
+      && rect.size.width > 0 && rect.size.height > 0
+  }
+
   public static func effectiveFrame(
     reportedFrame: CGRect,
-    viewport: CGRect,
+    viewport: SnapshotViewport,
     ancestorClip: CGRect?
   ) -> CGRect {
     var frame = reportedFrame
-    if !viewport.isInfinite {
-      frame = clipped(frame, to: viewport)
+    if let box = viewport.rect {
+      frame = clipped(frame, to: box)
     }
     if let ancestorClip {
       frame = clipped(frame, to: ancestorClip)
@@ -34,15 +43,18 @@ public enum SnapshotGeometry {
     )
   }
 
+  /// The shared `hittable` predicate (#1933), twin of `isGeometricallyActionable` in
+  /// `packages/kernel/src/rect.ts`, with `CGRect.contains`'s half-open right and bottom edges.
+  /// `nil` when only containment is left to decide and the capture has no viewport box: the node's
+  /// `hittable` is then absent on the wire, as it is on the host bridge (#2891).
   public static func isGeometricallyActionable(
     enabled: Bool,
     frame: CGRect,
-    viewport: CGRect
-  ) -> Bool {
-    guard enabled, !frame.isNull, !frame.isEmpty else { return false }
-    if viewport.isInfinite { return true }
-    let center = CGPoint(x: frame.midX, y: frame.midY)
-    return viewport.contains(center)
+    viewport: SnapshotViewport
+  ) -> Bool? {
+    guard enabled, isPositiveFinite(frame) else { return false }
+    guard let box = viewport.rect else { return nil }
+    return box.contains(CGPoint(x: frame.midX, y: frame.midY))
   }
 
   private static func clipped(_ frame: CGRect, to clip: CGRect) -> CGRect {
diff --git a/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotModels.swift b/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotModels.swift
index 95a3cf39d7..d0421aab6d 100644
--- a/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotModels.swift
+++ b/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotModels.swift
@@ -38,7 +38,8 @@ public struct RawAXNode: Equatable {
   public let enabled: Bool
   public let focused: Bool?
   public let selected: Bool?
-  public var hittable: Bool
+  /// Geometric actionability; `nil` when the capture has no viewport box to decide it against.
+  public var hittable: Bool?
   public let depth: Int
   public let parentIndex: Int?
   public let hiddenContentAbove: Bool?
@@ -55,7 +56,7 @@ public struct RawAXNode: Equatable {
     enabled: Bool,
     focused: Bool?,
     selected: Bool?,
-    hittable: Bool,
+    hittable: Bool?,
     depth: Int,
     parentIndex: Int?,
     hiddenContentAbove: Bool?,
@@ -79,7 +80,7 @@ public struct RawAXNode: Equatable {
     self.actions = actions
   }
 
-  func replacing(rect: SnapshotRect, hittable: Bool) -> RawAXNode {
+  func replacing(rect: SnapshotRect, hittable: Bool?) -> RawAXNode {
     var updated = self
     updated.rect = rect
     updated.hittable = hittable
@@ -153,15 +154,65 @@ public struct PresentationOptions: Equatable {
   }
 }
 
+/// What a capture knows about the viewport hosting its tree: the three cases of the host's
+/// `IosViewportEvidence` (#2891). No rectangle stands for "unknown".
+public enum SnapshotViewport: Equatable {
+  /// A box `SnapshotGeometry.isPositiveFinite` accepted. Only the factories below construct one.
+  public struct Box: Equatable {
+    public let rect: CGRect
+
+    init(positiveFinite rect: CGRect) {
+      self.rect = rect
+    }
+  }
+
+  /// The platform's box for the app's surface, with the interface orientation read in the same hop.
+  /// Only this case can anchor a rotation (#2612).
+  case reported(Box, interfaceOrientation: Int)
+  /// A box the capture inferred from its own root element. It clips and contains, and carries no
+  /// orientation, so it cannot anchor a rotation.
+  case derived(Box)
+  case missing(reason: MissingReason)
+
+  public enum MissingReason: Equatable {
+    /// The read was skipped or raised.
+    case notProvided
+    /// The box read is one `SnapshotGeometry.isPositiveFinite` refuses.
+    case invalid
+  }
+
+  public var rect: CGRect? {
+    switch self {
+    case .reported(let box, _), .derived(let box):
+      return box.rect
+    case .missing:
+      return nil
+    }
+  }
+
+  public static func reported(
+    box: CGRect,
+    interfaceOrientation: Int = RunnerInterfaceOrientation.unknown
+  ) -> SnapshotViewport {
+    SnapshotGeometry.isPositiveFinite(box)
+      ? .reported(Box(positiveFinite: box), interfaceOrientation: interfaceOrientation)
+      : .missing(reason: .invalid)
+  }
+
+  public static func derived(box: CGRect) -> SnapshotViewport {
+    SnapshotGeometry.isPositiveFinite(box)
+      ? .derived(Box(positiveFinite: box))
+      : .missing(reason: .invalid)
+  }
+}
+
 public struct SnapshotAcquisition {
   public let hint: CaptureHint
   public var nodes: [RawAXNode]
   public let truncated: Bool
   public let effectiveDepth: Int?
   public var customActions: SnapshotCustomActionCoverage?
-  public let viewport: CGRect
-  /// The app's interface orientation, consumed by the one `normalized` pass; `unknown` turns nothing.
-  public let interfaceOrientation: Int
+  public let viewport: SnapshotViewport
 
   public init(
     hint: CaptureHint,
@@ -169,8 +220,7 @@ public struct SnapshotAcquisition {
     truncated: Bool,
     effectiveDepth: Int?,
     customActions: SnapshotCustomActionCoverage? = nil,
-    viewport: CGRect,
-    interfaceOrientation: Int = 0
+    viewport: SnapshotViewport
   ) {
     self.hint = hint
     self.nodes = nodes
@@ -178,7 +228,6 @@ public struct SnapshotAcquisition {
     self.effectiveDepth = effectiveDepth
     self.customActions = customActions
     self.viewport = viewport
-    self.interfaceOrientation = interfaceOrientation
   }
 
   public func replacingNodes(_ nodes: [RawAXNode]) -> SnapshotAcquisition {
@@ -226,7 +275,7 @@ public struct PresentedNode: Codable, Equatable {
   public let enabled: Bool
   public let focused: Bool?
   public let selected: Bool?
-  public let hittable: Bool
+  public let hittable: Bool?
   public let depth: Int
   public let parentIndex: Int?
   public let hiddenContentAbove: Bool?
diff --git a/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotPresentationInvariant.swift b/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotPresentationInvariant.swift
index 7ce2f25589..a28ba33b2c 100644
--- a/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotPresentationInvariant.swift
+++ b/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotPresentationInvariant.swift
@@ -1,6 +1,7 @@
 import Foundation
 import CoreGraphics
 
+/// With no viewport box the cumulative clip has no root, so containment has nothing to violate.
 public enum SnapshotPresentationInvariant {
   struct ValidationStats: Equatable {
     let parentClipLookups: Int
@@ -12,7 +13,7 @@ public enum SnapshotPresentationInvariant {
 
   public static func validateRegular(
     _ nodes: [SnapshotPresentationNode],
-    viewport: CGRect,
+    viewport: SnapshotViewport,
     policy: SnapshotVisibilityFold.Policy
   ) throws {
     _ = try validateRegularWithStats(nodes, viewport: viewport, policy: policy)
@@ -20,24 +21,25 @@ public enum SnapshotPresentationInvariant {
 
   static func validateRegularWithStats(
     _ nodes: [SnapshotPresentationNode],
-    viewport: CGRect,
+    viewport: SnapshotViewport,
     policy: SnapshotVisibilityFold.Policy
   ) throws -> ValidationStats {
     var parentClipLookups = 0
-    var clipIncludingNodeByIndex: [Int: CGRect] = [:]
+    var clipIncludingNodeByIndex: [Int: CGRect?] = [:]
     clipIncludingNodeByIndex.reserveCapacity(nodes.count)
+    let rootClip = viewport.rect
 
     for node in nodes {
-      let ancestorClip: CGRect
+      let ancestorClip: CGRect?
       if let parentIndex = node.raw.parentIndex {
         parentClipLookups += 1
-        ancestorClip = clipIncludingNodeByIndex[parentIndex] ?? viewport
+        ancestorClip = clipIncludingNodeByIndex[parentIndex] ?? rootClip
       } else {
-        ancestorClip = viewport
+        ancestorClip = rootClip
       }
 
       let frame = node.effectiveRect.cgRect
-      let clipIncludingNode: CGRect
+      let clipIncludingNode: CGRect?
       if policy == .cursorProjected,
         SnapshotVisibilityFold.scrollContainerTypeNames.contains(node.raw.type),
         !frame.isNull,
@@ -50,7 +52,7 @@ public enum SnapshotPresentationInvariant {
       clipIncludingNodeByIndex[node.raw.index] = clipIncludingNode
 
       guard !frame.isNull, !frame.isEmpty else {
-        if node.raw.hittable {
+        if node.raw.hittable == true {
           throw SnapshotPresentationFailure.regularDegenerateNodeIsActionable(
             index: node.raw.index,
             frame: node.effectiveRect
@@ -59,11 +61,11 @@ public enum SnapshotPresentationInvariant {
         continue
       }
 
-      guard contains(frame, in: ancestorClip) else {
+      if let clip = ancestorClip, !contains(frame, in: clip) {
         throw SnapshotPresentationFailure.regularNodeOutsideCumulativeClip(
           index: node.raw.index,
           frame: node.effectiveRect,
-          clip: SnapshotRect(ancestorClip)
+          clip: SnapshotRect(clip)
         )
       }
     }
diff --git a/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotVisibilityFold.swift b/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotVisibilityFold.swift
index afd0b479c4..9f9a4d3ea3 100644
--- a/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotVisibilityFold.swift
+++ b/apple/snapshot-presentation/Sources/AgentDeviceSnapshotPresentation/SnapshotVisibilityFold.swift
@@ -100,7 +100,7 @@ public enum SnapshotVisibilityFold {
   public static func traversalDecision(
     for node: RawAXNode,
     parent: TraversalState,
-    viewport: CGRect,
+    viewport: SnapshotViewport,
     interactiveOnly: Bool,
     hasChildren: Bool,
     policy: Policy
@@ -153,7 +153,7 @@ public enum SnapshotVisibilityFold {
 
   public static func fold(
     _ nodes: [RawAXNode],
-    viewport: CGRect,
+    viewport: SnapshotViewport,
     interactiveOnly: Bool,
     policy: Policy
   ) -> [SnapshotPresentationNode] {
@@ -203,12 +203,17 @@ public enum SnapshotVisibilityFold {
               enabled: node.enabled,
               focused: node.focused,
               selected: node.selected,
-              hittable: node.parentIndex != nil && node.hittable
-                && SnapshotGeometry.isGeometricallyActionable(
-                  enabled: node.enabled,
-                  frame: decision.effectiveFrame,
-                  viewport: viewport
-                ),
+              hittable: node.parentIndex == nil
+                ? false
+                : node.hittable.flatMap { sourceHittable in
+                  sourceHittable
+                    ? SnapshotGeometry.isGeometricallyActionable(
+                      enabled: node.enabled,
+                      frame: decision.effectiveFrame,
+                      viewport: viewport
+                    )
+                    : false
+                },
               depth: outDepth,
               parentIndex: keptIndex,
               hiddenContentAbove: node.hiddenContentAbove,
diff --git a/apple/snapshot-presentation/Sources/SnapshotPresentationConformance/main.swift b/apple/snapshot-presentation/Sources/SnapshotPresentationConformance/main.swift
index 89bd98c4a1..005386ba10 100644
--- a/apple/snapshot-presentation/Sources/SnapshotPresentationConformance/main.swift
+++ b/apple/snapshot-presentation/Sources/SnapshotPresentationConformance/main.swift
@@ -75,7 +75,8 @@ private func acquisition(for input: ConformanceInput) -> SnapshotAcquisition {
     },
     truncated: false,
     effectiveDepth: nil,
-    viewport: input.viewport.cgRect
+    // The host engine refuses to fold without a viewport, so the differential always reports one.
+    viewport: .reported(box: input.viewport.cgRect)
   )
 }
 
diff --git a/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/ActionabilityPolicyTests.swift b/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/ActionabilityPolicyTests.swift
new file mode 100644
index 0000000000..27882e1442
--- /dev/null
+++ b/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/ActionabilityPolicyTests.swift
@@ -0,0 +1,118 @@
+import AgentDeviceSnapshotPresentation
+import CoreGraphics
+import Foundation
+import XCTest
+
+/// Replays `contracts/fixtures/snapshot-actionability-policy.json` against the Swift predicate. The
+/// TypeScript twin replays the same rows in `scripts/ios-snapshot-differential.test.ts`.
+final class ActionabilityPolicyTests: XCTestCase {
+  private struct Table: Decodable {
+    let cases: [PolicyCase]
+  }
+
+  private struct ViewportFact: Decodable {
+    private enum CodingKeys: String, CodingKey {
+      case kind, rect, reason
+    }
+
+    let declaredKind: String
+    let viewport: SnapshotViewport
+
+    /// A row whose box the factory refuses would silently test `missing` under another label.
+    var matchesDeclaredKind: Bool {
+      switch (declaredKind, viewport) {
+      case ("reported", .reported), ("derived", .derived), ("missing", .missing):
+        return true
+      default:
+        return false
+      }
+    }
+
+    init(from decoder: Decoder) throws {
+      let container = try decoder.container(keyedBy: CodingKeys.self)
+      let kind = try container.decode(String.self, forKey: .kind)
+      self.declaredKind = kind
+      switch kind {
+      case "reported":
+        self.viewport = .reported(box: try container.decode(FixtureRect.self, forKey: .rect).cgRect)
+      case "derived":
+        self.viewport = .derived(box: try container.decode(FixtureRect.self, forKey: .rect).cgRect)
+      case "missing":
+        switch try container.decode(String.self, forKey: .reason) {
+        case "not-provided":
+          self.viewport = .missing(reason: .notProvided)
+        case "invalid":
+          self.viewport = .missing(reason: .invalid)
+        default:
+          throw DecodingError.dataCorruptedError(
+            forKey: .reason,
+            in: container,
+            debugDescription: "unknown missing-viewport reason"
+          )
+        }
+      default:
+        throw DecodingError.dataCorruptedError(
+          forKey: .kind,
+          in: container,
+          debugDescription: "unknown viewport kind"
+        )
+      }
+    }
+  }
+
+  private struct PolicyCase: Decodable {
+    let name: String
+    let swift: Bool
+    let typescript: Bool
+    let asymmetry: String?
+    let enabled: Bool
+    let node: FixtureRect
+    let viewport: ViewportFact
+    /// `nil` is the absent bit.
+    let hittable: Bool?
+    let nodeRectGuardPasses: Bool
+
+    var declaresItsAsymmetry: Bool {
+      (swift && typescript) != (asymmetry?.isEmpty == false)
+    }
+  }
+
+  func testActionabilityPolicyAgreesWithEveryGoldenVector() throws {
+    let table = try JSONDecoder().decode(
+      Table.self,
+      from: Data(contentsOf: contractsFixtureURL("snapshot-actionability-policy.json"))
+    )
+    XCTAssertEqual(Set(table.cases.map(\.name)).count, table.cases.count, "names must be unique")
+    let swiftCases = table.cases.filter(\.swift)
+    XCTAssertEqual(
+      Set(swiftCases.map(\.viewport.declaredKind)),
+      ["reported", "derived", "missing"]
+    )
+    for testCase in table.cases {
+      XCTAssertTrue(
+        testCase.declaresItsAsymmetry,
+        "\(testCase.name): a row both languages do not share must name the asymmetry"
+      )
+    }
+    for testCase in swiftCases {
+      XCTAssertTrue(
+        testCase.viewport.matchesDeclaredKind,
+        "\(testCase.name): declared \(testCase.viewport.declaredKind) must survive declaration"
+      )
+      XCTAssertEqual(
+        SnapshotGeometry.isPositiveFinite(testCase.node.cgRect),
+        testCase.nodeRectGuardPasses,
+        "\(testCase.name): node-rect guard"
+      )
+      XCTAssertEqual(
+        SnapshotGeometry.isGeometricallyActionable(
+          enabled: testCase.enabled,
+          frame: testCase.node.cgRect,
+          viewport: testCase.viewport.viewport
+        ),
+        testCase.hittable,
+        testCase.name
+      )
+    }
+  }
+}
diff --git a/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/ConformanceTests.swift b/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/ConformanceTests.swift
index 2e526095bf..d99fdda405 100644
--- a/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/ConformanceTests.swift
+++ b/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/ConformanceTests.swift
@@ -49,7 +49,7 @@ final class ConformanceTests: XCTestCase {
         ],
         truncated: false,
         effectiveDepth: nil,
-        viewport: CGRect(x: 0, y: 0, width: 100, height: 100)
+        viewport: .reported(box: CGRect(x: 0, y: 0, width: 100, height: 100))
       ),
       options: options,
       policy: .cursorProjected
diff --git a/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/CoordinateSpaceTests.swift b/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/CoordinateSpaceTests.swift
index 90e67e938d..c5df2bc22c 100644
--- a/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/CoordinateSpaceTests.swift
+++ b/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/CoordinateSpaceTests.swift
@@ -7,30 +7,7 @@ import XCTest
 /// without a simulator, and the runner's walkers are tested separately for threading it through.
 final class CoordinateSpaceTests: XCTestCase {
   private struct WindowCoordinateSpaceFixture: Decodable {
-    /// A frame as JSON can carry one. Infinity has no JSON spelling, so the unusable box a platform
-    /// hands back is named `{"infinite": true}`: `CGRect.infinite` here, and an infinite rect in the
-    /// vitest twin.
-    struct Frame: Decodable {
-      private enum CodingKeys: String, CodingKey {
-        case x, y, width, height, infinite
-      }
-
-      let cgRect: CGRect
-
-      init(from decoder: Decoder) throws {
-        let container = try decoder.container(keyedBy: CodingKeys.self)
-        guard try container.decodeIfPresent(Bool.self, forKey: .infinite) != true else {
-          self.cgRect = .infinite
-          return
-        }
-        self.cgRect = CGRect(
-          x: try container.decode(Double.self, forKey: .x),
-          y: try container.decode(Double.self, forKey: .y),
-          width: try container.decode(Double.self, forKey: .width),
-          height: try container.decode(Double.self, forKey: .height)
-        )
-      }
-    }
+    typealias Frame = FixtureRect
 
     struct Constants: Decodable {
       let quarterTurnTolerance: Double
@@ -161,10 +138,9 @@ final class CoordinateSpaceTests: XCTestCase {
       reportedBySurfaceHost: true,
       reportedFrame: CGRect(x: 0, y: 0, width: 402, height: 874),
       inheritedFrom: .appOrientation,
-      appFrame: appFrame,
-      interfaceOrientation: landscape
+      viewport: .reported(box: appFrame, interfaceOrientation: landscape)
     )
-    XCTAssertEqual(space, .deviceNative(appFrame: appFrame, interfaceOrientation: landscape))
+    XCTAssertEqual(space, deviceNative(appFrame, landscape))
 
     // Reported on iPhone 17 Pro (iOS 26.2), landscape, system keyboard over the fixture's form.
     XCTAssertEqual(
@@ -198,8 +174,10 @@ final class CoordinateSpaceTests: XCTestCase {
       reportedBySurfaceHost: true,
       reportedFrame: rotated,
       inheritedFrom: .appOrientation,
-      appFrame: appFrame,
-      interfaceOrientation: RunnerInterfaceOrientation.landscapeRight
+      viewport: .reported(
+        box: appFrame,
+        interfaceOrientation: RunnerInterfaceOrientation.landscapeRight
+      )
     )
 
     // The app's own window reports the app's box, and so does a hosted surface that already
@@ -209,8 +187,10 @@ final class CoordinateSpaceTests: XCTestCase {
         reportedBySurfaceHost: true,
         reportedFrame: appFrame,
         inheritedFrom: nativeSpace,
-        appFrame: appFrame,
-        interfaceOrientation: RunnerInterfaceOrientation.landscapeRight
+        viewport: .reported(
+          box: appFrame,
+          interfaceOrientation: RunnerInterfaceOrientation.landscapeRight
+        )
       ),
       .appOrientation
     )
@@ -223,8 +203,10 @@ final class CoordinateSpaceTests: XCTestCase {
         ),
         reportedFrame: CGRect(x: 154, y: 77, width: 45, height: 72),
         inheritedFrom: nativeSpace,
-        appFrame: appFrame,
-        interfaceOrientation: RunnerInterfaceOrientation.landscapeRight
+        viewport: .reported(
+          box: appFrame,
+          interfaceOrientation: RunnerInterfaceOrientation.landscapeRight
+        )
       ),
       nativeSpace
     )
@@ -234,8 +216,7 @@ final class CoordinateSpaceTests: XCTestCase {
       reportedBySurfaceHost: true,
       reportedFrame: rotated,
       inheritedFrom: .appOrientation,
-      appFrame: appFrame,
-      interfaceOrientation: RunnerInterfaceOrientation.unknown
+      viewport: .reported(box: appFrame, interfaceOrientation: RunnerInterfaceOrientation.unknown)
     )
     XCTAssertEqual(unnamed, .appOrientation)
     XCTAssertEqual(
@@ -248,22 +229,26 @@ final class CoordinateSpaceTests: XCTestCase {
         reportedBySurfaceHost: true,
         reportedFrame: rotated,
         inheritedFrom: .appOrientation,
-        appFrame: CGRect(x: 16, y: 24, width: 874, height: 402),
-        interfaceOrientation: RunnerInterfaceOrientation.portrait
-      ),
-      .appOrientation
-    )
-    // An app frame the capture could not resolve cannot anchor a rotation.
-    XCTAssertEqual(
-      SnapshotGeometrySpace.space(
-        reportedBySurfaceHost: true,
-        reportedFrame: rotated,
-        inheritedFrom: .appOrientation,
-        appFrame: .infinite,
-        interfaceOrientation: RunnerInterfaceOrientation.landscapeRight
+        viewport: .reported(
+          box: CGRect(x: 16, y: 24, width: 874, height: 402),
+          interfaceOrientation: RunnerInterfaceOrientation.portrait
+        )
       ),
       .appOrientation
     )
+    // Only a reported viewport carries an orientation: no box, or a box the capture derived from
+    // its own root, cannot anchor a rotation (#2891).
+    for viewport in [SnapshotViewport.missing(reason: .notProvided), .derived(box: appFrame)] {
+      XCTAssertEqual(
+        SnapshotGeometrySpace.space(
+          reportedBySurfaceHost: true,
+          reportedFrame: rotated,
+          inheritedFrom: .appOrientation,
+          viewport: viewport
+        ),
+        .appOrientation
+      )
+    }
     // A square app cannot be told from its own quarter turn, so its geometry is left alone.
     let square = CGRect(x: 0, y: 0, width: 800, height: 800)
     XCTAssertEqual(
@@ -271,8 +256,10 @@ final class CoordinateSpaceTests: XCTestCase {
         reportedBySurfaceHost: true,
         reportedFrame: square,
         inheritedFrom: .appOrientation,
-        appFrame: square,
-        interfaceOrientation: RunnerInterfaceOrientation.landscapeRight
+        viewport: .reported(
+          box: square,
+          interfaceOrientation: RunnerInterfaceOrientation.landscapeRight
+        )
       ),
       .appOrientation
     )
@@ -293,18 +280,16 @@ final class CoordinateSpaceTests: XCTestCase {
       reportedBySurfaceHost: true,
       reportedFrame: appFrame,
       inheritedFrom: .appOrientation,
-      appFrame: appFrame,
-      interfaceOrientation: landscape
+      viewport: .reported(box: appFrame, interfaceOrientation: landscape)
     )
     XCTAssertEqual(windowSpace, .appOrientation)
     let surfaceSpace = SnapshotGeometrySpace.space(
       reportedBySurfaceHost: true,
       reportedFrame: turned,
       inheritedFrom: windowSpace,
-      appFrame: appFrame,
-      interfaceOrientation: landscape
+      viewport: .reported(box: appFrame, interfaceOrientation: landscape)
     )
-    XCTAssertEqual(surfaceSpace, .deviceNative(appFrame: appFrame, interfaceOrientation: landscape))
+    XCTAssertEqual(surfaceSpace, deviceNative(appFrame, landscape))
     // Deep in the tree a turned box is content reporting large bounds, not a hosted surface: it keeps
     // the space it inherited rather than rewriting the space below it.
     XCTAssertEqual(
@@ -312,8 +297,7 @@ final class CoordinateSpaceTests: XCTestCase {
         reportedBySurfaceHost: false,
         reportedFrame: turned,
         inheritedFrom: windowSpace,
-        appFrame: appFrame,
-        interfaceOrientation: landscape
+        viewport: .reported(box: appFrame, interfaceOrientation: landscape)
       ),
       .appOrientation
     )
@@ -340,15 +324,14 @@ final class CoordinateSpaceTests: XCTestCase {
         RunnerInterfaceOrientation.landscapeRight, RunnerInterfaceOrientation.landscapeLeft
       ] {
         let expected: SnapshotGeometrySpace = testCase.quarterTurned
-          ? .deviceNative(appFrame: appFrame, interfaceOrientation: interfaceOrientation)
+          ? deviceNative(appFrame, interfaceOrientation)
           : .appOrientation
         XCTAssertEqual(
           SnapshotGeometrySpace.space(
             reportedBySurfaceHost: true,
             reportedFrame: testCase.window.cgRect,
             inheritedFrom: .appOrientation,
-            appFrame: appFrame,
-            interfaceOrientation: interfaceOrientation
+            viewport: .reported(box: appFrame, interfaceOrientation: interfaceOrientation)
           ),
           expected,
           "\(testCase.name) (interfaceOrientation \(interfaceOrientation))"
@@ -368,16 +351,15 @@ final class CoordinateSpaceTests: XCTestCase {
     }
   }
 
+  private func deviceNative(_ appFrame: CGRect, _ interfaceOrientation: Int) -> SnapshotGeometrySpace {
+    guard case .reported(let box, _) = SnapshotViewport.reported(box: appFrame) else {
+      preconditionFailure("\(appFrame) is not a viewport box")
+    }
+    return .deviceNative(appFrame: box, interfaceOrientation: interfaceOrientation)
+  }
+
   private func loadWindowCoordinateSpaceFixture() throws -> WindowCoordinateSpaceFixture {
-    let fixtureURL = URL(fileURLWithPath: #filePath)
-      .deletingLastPathComponent() // AgentDeviceSnapshotPresentationTests
-      .deletingLastPathComponent() // Tests
-      .deletingLastPathComponent() // snapshot-presentation
-      .deletingLastPathComponent() // apple
-      .deletingLastPathComponent() // repo root
-      .appendingPathComponent("contracts")
-      .appendingPathComponent("fixtures")
-      .appendingPathComponent("window-coordinate-space.json")
+    let fixtureURL = contractsFixtureURL("window-coordinate-space.json")
     return try JSONDecoder().decode(
       WindowCoordinateSpaceFixture.self,
       from: Data(contentsOf: fixtureURL)
@@ -421,8 +403,7 @@ final class CoordinateSpaceTests: XCTestCase {
       let expected = (namesQuarterTurn && !squareApp) ? testCase.oriented : testCase.native
       let normalized = SnapshotGeometrySpace.normalized(
         nodes: turnedSubtree(app: app, reportedLeaf: testCase.native.cgRect),
-        viewport: app,
-        interfaceOrientation: testCase.interfaceOrientation
+        viewport: .reported(box: app, interfaceOrientation: testCase.interfaceOrientation)
       )
       XCTAssertEqual(normalized.count, 4)
       XCTAssertEqual(normalized[3].rect.cgRect, expected.cgRect, testCase.name)
@@ -443,8 +424,7 @@ final class CoordinateSpaceTests: XCTestCase {
     ]
     let normalized = SnapshotGeometrySpace.normalized(
       nodes: acquired,
-      viewport: app,
-      interfaceOrientation: RunnerInterfaceOrientation.landscapeRight
+      viewport: .reported(box: app, interfaceOrientation: RunnerInterfaceOrientation.landscapeRight)
     )
     XCTAssertEqual(
       normalized.first { $0.label == "planeBand" }?.rect,
@@ -470,8 +450,7 @@ final class CoordinateSpaceTests: XCTestCase {
     ]
     let normalized = SnapshotGeometrySpace.normalized(
       nodes: acquired,
-      viewport: app,
-      interfaceOrientation: RunnerInterfaceOrientation.unknown
+      viewport: .reported(box: app, interfaceOrientation: RunnerInterfaceOrientation.unknown)
     )
     XCTAssertEqual(normalized.map(\.rect), acquired.map(\.rect))
     XCTAssertEqual(normalized[1].hittable, true)
@@ -479,12 +458,42 @@ final class CoordinateSpaceTests: XCTestCase {
     XCTAssertEqual(normalized[0].hittable, false)
   }
 
+  /// Without a viewport box the pass turns nothing and cannot decide containment, so a child's
+  /// `hittable` is absent rather than declared; a disabled child is still declared `false` (#2891).
+  func testNormalizedWithoutAViewportLeavesContainmentUndecided() {
+    let app = CGRect(x: 0, y: 0, width: 874, height: 402)
+    let acquired = turnedSubtree(app: app, reportedLeaf: CGRect(x: 100, y: 100, width: 40, height: 20))
+    let normalized = SnapshotGeometrySpace.normalized(
+      nodes: acquired,
+      viewport: .missing(reason: .notProvided)
+    )
+    XCTAssertEqual(normalized.map(\.rect), acquired.map(\.rect))
+    XCTAssertEqual(normalized[0].hittable, false)
+    XCTAssertNil(normalized[3].hittable)
+
+    let disabled = RawAXNode(
+      index: 1, type: "Button", label: nil, identifier: nil, value: nil,
+      rect: SnapshotRect(x: 100, y: 100, width: 40, height: 20),
+      enabled: false, focused: nil, selected: nil, hittable: true,
+      depth: 1, parentIndex: 0, hiddenContentAbove: nil, hiddenContentBelow: nil
+    )
+    XCTAssertEqual(
+      SnapshotGeometrySpace.normalized(
+        nodes: [acquired[0], disabled],
+        viewport: .missing(reason: .notProvided)
+      )[1].hittable,
+      false
+    )
+  }
+
   func testNormalizedOfAnEmptyArrayIsEmpty() {
     XCTAssertEqual(
       SnapshotGeometrySpace.normalized(
         nodes: [],
-        viewport: CGRect(x: 0, y: 0, width: 874, height: 402),
-        interfaceOrientation: RunnerInterfaceOrientation.landscapeRight
+        viewport: .reported(
+          box: CGRect(x: 0, y: 0, width: 874, height: 402),
+          interfaceOrientation: RunnerInterfaceOrientation.landscapeRight
+        )
       ),
       []
     )
diff --git a/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/FixtureRect.swift b/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/FixtureRect.swift
new file mode 100644
index 0000000000..f3152d43b4
--- /dev/null
+++ b/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/FixtureRect.swift
@@ -0,0 +1,41 @@
+import CoreGraphics
+import Foundation
+
+/// A rect as a `contracts/fixtures/` table spells it. JSON has no infinity, so the two unusable
+/// boxes are named: `{"infinite": true}` is `CGRect.infinite`, and `{"nonFinite": true}` is a
+/// box whose components are infinite.
+struct FixtureRect: Decodable {
+  private enum CodingKeys: String, CodingKey {
+    case x, y, width, height, infinite, nonFinite
+  }
+
+  let cgRect: CGRect
+
+  init(from decoder: Decoder) throws {
+    let container = try decoder.container(keyedBy: CodingKeys.self)
+    if try container.decodeIfPresent(Bool.self, forKey: .infinite) == true {
+      self.cgRect = .infinite
+    } else if try container.decodeIfPresent(Bool.self, forKey: .nonFinite) == true {
+      self.cgRect = CGRect(x: -.infinity, y: -.infinity, width: .infinity, height: .infinity)
+    } else {
+      self.cgRect = CGRect(
+        x: try container.decode(Double.self, forKey: .x),
+        y: try container.decode(Double.self, forKey: .y),
+        width: try container.decode(Double.self, forKey: .width),
+        height: try container.decode(Double.self, forKey: .height)
+      )
+    }
+  }
+}
+
+func contractsFixtureURL(_ name: String, from filePath: String = #filePath) -> URL {
+  URL(fileURLWithPath: filePath)
+    .deletingLastPathComponent() // AgentDeviceSnapshotPresentationTests
+    .deletingLastPathComponent() // Tests
+    .deletingLastPathComponent() // snapshot-presentation
+    .deletingLastPathComponent() // apple
+    .deletingLastPathComponent() // repo root
+    .appendingPathComponent("contracts")
+    .appendingPathComponent("fixtures")
+    .appendingPathComponent(name)
+}
diff --git a/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/InvariantTests.swift b/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/InvariantTests.swift
index 6b06f8c5a4..2a2eee8f48 100644
--- a/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/InvariantTests.swift
+++ b/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/InvariantTests.swift
@@ -28,7 +28,7 @@ final class InvariantTests: XCTestCase {
 
     let stats = try SnapshotPresentationInvariant.validateRegularWithStats(
       nodes,
-      viewport: viewport,
+      viewport: .reported(box: viewport),
       policy: .cursorProjected
     )
 
diff --git a/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/RegularDepthTests.swift b/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/RegularDepthTests.swift
index 6d7bc3f529..5589a9c304 100644
--- a/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/RegularDepthTests.swift
+++ b/apple/snapshot-presentation/Tests/AgentDeviceSnapshotPresentationTests/RegularDepthTests.swift
@@ -21,7 +21,7 @@ final class RegularDepthTests: XCTestCase {
       nodes: nodes,
       truncated: false,
       effectiveDepth: nil,
-      viewport: viewport
+      viewport: .reported(box: viewport)
     )
 
     let result = try XCTUnwrap(SnapshotPresentation.present(acquisition, options: options))
diff --git a/contracts/fixtures/snapshot-actionability-policy.json b/contracts/fixtures/snapshot-actionability-policy.json
new file mode 100644
index 0000000000..5a567f6495
--- /dev/null
+++ b/contracts/fixtures/snapshot-actionability-policy.json
@@ -0,0 +1,220 @@
+{
+  "description": "Golden vector table for the shared `hittable` predicate (#1933, #2891), for input shapes the fixed 320x240 fold fixture in ios-snapshot-engine-conformance.json cannot reach. RULE: a node is actionable when it is enabled, its own rect is positive and finite, and its center falls inside the viewport box, half-open on the right and bottom edges. Implementations: SnapshotGeometry.isGeometricallyActionable (Swift, replayed by ActionabilityPolicyTests) and isGeometricallyActionable in packages/kernel/src/rect.ts (replayed by scripts/ios-snapshot-differential.test.ts). The viewport is the declared fact `reported`, `derived`, or `missing` (IosViewportEvidence). `hittable: null` is the absent bit: with no viewport box, containment is undecided. Every row declares `swift` and `typescript`; a row one side skips carries `asymmetry`.",
+  "cases": [
+    {
+      "name": "a center strictly inside the reported box is actionable",
+      "swift": true,
+      "typescript": true,
+      "enabled": true,
+      "node": { "x": 100, "y": 100, "width": 40, "height": 20 },
+      "viewport": { "kind": "reported", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": true,
+      "nodeRectGuardPasses": true
+    },
+    {
+      "name": "a center one point short of the right edge is actionable",
+      "swift": true,
+      "typescript": true,
+      "enabled": true,
+      "node": { "x": 239, "y": 110, "width": 160, "height": 20 },
+      "viewport": { "kind": "reported", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": true,
+      "nodeRectGuardPasses": true
+    },
+    {
+      "name": "a center landing exactly on the right edge is not actionable: the edge is half-open",
+      "swift": true,
+      "typescript": true,
+      "enabled": true,
+      "node": { "x": 240, "y": 110, "width": 160, "height": 20 },
+      "viewport": { "kind": "reported", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": false,
+      "nodeRectGuardPasses": true
+    },
+    {
+      "name": "a center one point short of the bottom edge is actionable",
+      "swift": true,
+      "typescript": true,
+      "enabled": true,
+      "node": { "x": 100, "y": 159, "width": 40, "height": 160 },
+      "viewport": { "kind": "reported", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": true,
+      "nodeRectGuardPasses": true
+    },
+    {
+      "name": "a center landing exactly on the bottom edge is not actionable: the edge is half-open",
+      "swift": true,
+      "typescript": true,
+      "enabled": true,
+      "node": { "x": 100, "y": 160, "width": 40, "height": 160 },
+      "viewport": { "kind": "reported", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": false,
+      "nodeRectGuardPasses": true
+    },
+    {
+      "name": "a center landing exactly on the left edge is actionable: that edge is inclusive",
+      "swift": true,
+      "typescript": true,
+      "enabled": true,
+      "node": { "x": -20, "y": 100, "width": 40, "height": 20 },
+      "viewport": { "kind": "reported", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": true,
+      "nodeRectGuardPasses": true
+    },
+    {
+      "name": "a center landing exactly on the top edge is actionable: that edge is inclusive",
+      "swift": true,
+      "typescript": true,
+      "enabled": true,
+      "node": { "x": 100, "y": -10, "width": 40, "height": 20 },
+      "viewport": { "kind": "reported", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": true,
+      "nodeRectGuardPasses": true
+    },
+    {
+      "name": "a disabled node is not actionable even with its center inside the box",
+      "swift": true,
+      "typescript": true,
+      "enabled": false,
+      "node": { "x": 100, "y": 100, "width": 40, "height": 20 },
+      "viewport": { "kind": "reported", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": false,
+      "nodeRectGuardPasses": true
+    },
+    {
+      "name": "a center inside the box reached through a canonical box is actionable",
+      "swift": true,
+      "typescript": true,
+      "enabled": true,
+      "node": { "x": 80, "y": 100, "width": 20, "height": 20 },
+      "viewport": { "kind": "reported", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": true,
+      "nodeRectGuardPasses": true
+    },
+    {
+      "name": "the same center reached through a negative width is not actionable: the node guard decides, and Swift used to answer actionable",
+      "swift": true,
+      "typescript": true,
+      "enabled": true,
+      "node": { "x": 100, "y": 100, "width": -20, "height": 20 },
+      "viewport": { "kind": "reported", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": false,
+      "nodeRectGuardPasses": false
+    },
+    {
+      "name": "a center inside the box reached through a zero width is not actionable",
+      "swift": true,
+      "typescript": true,
+      "enabled": true,
+      "node": { "x": 100, "y": 110, "width": 0, "height": 20 },
+      "viewport": { "kind": "reported", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": false,
+      "nodeRectGuardPasses": false
+    },
+    {
+      "name": "that zero-area box's center reached through a canonical box is actionable",
+      "swift": true,
+      "typescript": true,
+      "enabled": true,
+      "node": { "x": 90, "y": 110, "width": 20, "height": 20 },
+      "viewport": { "kind": "reported", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": true,
+      "nodeRectGuardPasses": true
+    },
+    {
+      "name": "Apple's no-box sentinel is not actionable: CGRect.infinite is made of finite Doubles whose center is (0,0), so only the platform that owns that value can refuse it by identity",
+      "swift": true,
+      "typescript": false,
+      "asymmetry": "Swift decodes {\"infinite\": true} as CGRect.infinite; TypeScript has no such value, and frameFromGuest in packages/platform-apple/src/snapshot-source/tree.ts refuses a frame whose components are not Number.isFinite before the predicate ever sees it, which is the row below. The sentinel's components are finite, so TypeScript would call them actionable: the refusal belongs to the producer that parses an Apple frame, not to a magic value inside the shared rule.",
+      "enabled": true,
+      "node": { "infinite": true },
+      "viewport": { "kind": "reported", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": false,
+      "nodeRectGuardPasses": false
+    },
+    {
+      "name": "a node rect whose components are not finite is not actionable on either producer, and the component checks refuse it before any center is computed",
+      "swift": true,
+      "typescript": true,
+      "enabled": true,
+      "node": { "nonFinite": true },
+      "viewport": { "kind": "reported", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": false,
+      "nodeRectGuardPasses": false
+    },
+    {
+      "name": "the center a box spelled infinite lands on is actionable when a real box reaches it",
+      "swift": true,
+      "typescript": true,
+      "enabled": true,
+      "node": { "x": -10, "y": -10, "width": 20, "height": 20 },
+      "viewport": { "kind": "reported", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": true,
+      "nodeRectGuardPasses": true
+    },
+    {
+      "name": "the same node whose center sits inside a reported box has no hittable bit once the viewport goes missing",
+      "swift": true,
+      "typescript": false,
+      "asymmetry": "The TypeScript predicate takes a box. Without one, each host path withholds the bit before asking it: the bridge reader publishes derived hittability only for a reported viewport, and resolveViewportEvidence refuses to fold a regular presentation.",
+      "enabled": true,
+      "node": { "x": 100, "y": 100, "width": 40, "height": 20 },
+      "viewport": { "kind": "missing", "reason": "not-provided" },
+      "hittable": null,
+      "nodeRectGuardPasses": true
+    },
+    {
+      "name": "a viewport declared invalid leaves the bit absent the same way",
+      "swift": true,
+      "typescript": false,
+      "asymmetry": "The TypeScript predicate takes a box. Without one, each host path withholds the bit before asking it: the bridge reader publishes derived hittability only for a reported viewport, and resolveViewportEvidence refuses to fold a regular presentation.",
+      "enabled": true,
+      "node": { "x": 100, "y": 100, "width": 40, "height": 20 },
+      "viewport": { "kind": "missing", "reason": "invalid" },
+      "hittable": null,
+      "nodeRectGuardPasses": true
+    },
+    {
+      "name": "a disabled node is not actionable without a viewport: that half of the rule needs no box",
+      "swift": true,
+      "typescript": false,
+      "asymmetry": "The TypeScript predicate takes a box. Without one, each host path withholds the bit before asking it: the bridge reader publishes derived hittability only for a reported viewport, and resolveViewportEvidence refuses to fold a regular presentation.",
+      "enabled": false,
+      "node": { "x": 100, "y": 100, "width": 40, "height": 20 },
+      "viewport": { "kind": "missing", "reason": "not-provided" },
+      "hittable": false,
+      "nodeRectGuardPasses": true
+    },
+    {
+      "name": "a zero-area node is not actionable without a viewport: the node guard needs no box",
+      "swift": true,
+      "typescript": false,
+      "asymmetry": "The TypeScript predicate takes a box. Without one, each host path withholds the bit before asking it: the bridge reader publishes derived hittability only for a reported viewport, and resolveViewportEvidence refuses to fold a regular presentation.",
+      "enabled": true,
+      "node": { "x": 100, "y": 100, "width": 0, "height": 20 },
+      "viewport": { "kind": "missing", "reason": "not-provided" },
+      "hittable": false,
+      "nodeRectGuardPasses": false
+    },
+    {
+      "name": "a derived box the capture read from its own root still answers containment",
+      "swift": true,
+      "typescript": true,
+      "enabled": true,
+      "node": { "x": 100, "y": 100, "width": 40, "height": 20 },
+      "viewport": { "kind": "derived", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": true,
+      "nodeRectGuardPasses": true
+    },
+    {
+      "name": "a derived box still refuses a node whose center is off that box",
+      "swift": true,
+      "typescript": true,
+      "enabled": true,
+      "node": { "x": 900, "y": 10, "width": 40, "height": 20 },
+      "viewport": { "kind": "derived", "rect": { "x": 0, "y": 0, "width": 320, "height": 240 } },
+      "hittable": false,
+      "nodeRectGuardPasses": true
+    }
+  ]
+}
diff --git a/docs/adr/0004-ios-snapshot-backend-strategy.md b/docs/adr/0004-ios-snapshot-backend-strategy.md
index dc46f6db6c..9610cc8bb9 100644
--- a/docs/adr/0004-ios-snapshot-backend-strategy.md
+++ b/docs/adr/0004-ios-snapshot-backend-strategy.md
@@ -304,6 +304,16 @@ a typed `IOS_SNAPSHOT_PRESENTATION_FAILED` capture failure with the named `prese
 snapshot-quality reason, preserved through recovery and the existing TypeScript verdict/warning
 contract.
 
+Inside the runner the viewport is a declared fact, not a rectangle: `SnapshotViewport` is
+`reported(box, interfaceOrientation)`, `derived(box)`, or `missing(reason)`, the cases of the host's
+`IosViewportEvidence` (#2891). Only `reported` carries an orientation, so only it can anchor a
+rotation in `SnapshotGeometrySpace`. With no box the clip skips, the cumulative-clip invariant has no
+root clip to violate, and a node whose actionability depends on containment has no `hittable` on the
+wire, as on the host bridge; disabled or degenerate nodes stay declared `false`. The runner route's
+host evidence comes from the payload's root nodes (`resolveIosViewportEvidenceFromRoots` in
+`packages/capture-kit/src/ios-snapshot-acquisition.ts`). `contracts/fixtures/snapshot-actionability-policy.json`
+pins the predicate for shapes the 320x240 fold fixture cannot reach.
+
 A regular `--depth` request is a presentation cut, not an acquisition bound. `CaptureHint` keeps raw
 traversal depth (`--raw --depth`) separate from regular presented depth, but the recursive tree walk
 no longer reads presented depth (or any geometry) while descending: for a regular capture it
diff --git a/packages/kernel/src/rect.ts b/packages/kernel/src/rect.ts
index fe25acfe7d..a6ebb19bc5 100644
--- a/packages/kernel/src/rect.ts
+++ b/packages/kernel/src/rect.ts
@@ -1,5 +1,6 @@
 import type { Rect } from './snapshot.ts';
 
+/** Twin of `SnapshotGeometry.isPositiveFinite` on the runner (#2891). */
 export function isPositiveFiniteRect(rect: Rect | undefined): rect is Rect {
   return Boolean(
     rect &&
@@ -29,13 +30,12 @@ export function containsPoint(rect: Rect, x: number, y: number): boolean {
 
 /**
  * The shared `hittable` predicate every iOS snapshot producer publishes (#1933): an enabled node
- * with a positive frame whose center falls inside the viewport. It is the TypeScript twin of the
- * runner's Swift `SnapshotGeometry.isGeometricallyActionable`, including `CGRect.contains`'s
- * half-open right/bottom edges — a center landing exactly on the viewport's right or bottom edge is
- * not hittable on either producer. The host AX bridge derives the source bit from the node's own
- * frame and the fold intersects it with the clipped frame, so a `hittable:` selector cannot tell the
- * two producers apart. Kept here so both packages read one definition rather than each re-encoding
- * the rule.
+ * with a positive finite frame whose center falls inside the viewport. It is the TypeScript twin of
+ * the runner's Swift `SnapshotGeometry.isGeometricallyActionable`, including `CGRect.contains`'s
+ * half-open right/bottom edges; `contracts/fixtures/snapshot-actionability-policy.json` pins both.
+ * Callers without a viewport box withhold the bit instead of asking. The host AX bridge derives the
+ * source bit from the node's own frame and the fold intersects it with the clipped frame, so a
+ * `hittable:` selector cannot tell the two producers apart.
  */
 export function isGeometricallyActionable(
   enabled: boolean,
diff --git a/packages/platform-apple/src/runner/__tests__/snapshot-presentation.test.ts b/packages/platform-apple/src/runner/__tests__/snapshot-presentation.test.ts
index a21f130552..917efddbd9 100644
--- a/packages/platform-apple/src/runner/__tests__/snapshot-presentation.test.ts
+++ b/packages/platform-apple/src/runner/__tests__/snapshot-presentation.test.ts
@@ -207,6 +207,33 @@ test('a healthy payload with valid viewport roots still presents', () => {
   );
 });
 
+// A runner capture with no viewport box omits `hittable` on the nodes it could not decide (#2891);
+// the host presents them undecided rather than minting a value.
+test('a runner payload with the hittable bit absent presents without declaring it', () => {
+  const nodes: RawSnapshotNode[] = [
+    {
+      index: 0,
+      type: 'Application',
+      rect: { x: 0, y: 0, width: 390, height: 844 },
+      hittable: false,
+    },
+    { index: 1, parentIndex: 0, type: 'Other', rect: { x: 0, y: 0, width: 390, height: 844 } },
+    {
+      index: 2,
+      parentIndex: 1,
+      type: 'Button',
+      label: 'Not Now',
+      rect: { x: 16, y: 400, width: 80, height: 32 },
+    },
+  ];
+  for (const interactiveOnly of [false, true]) {
+    const presented = presentAppleRunnerSnapshot('device-1', { interactiveOnly }, { nodes });
+    const button = presented.find((node) => node.label === 'Not Now');
+    assert.ok(button, `interactiveOnly=${interactiveOnly}: the undecided button is presented`);
+    assert.equal('hittable' in button, false);
+  }
+});
+
 // The keyboard band the runner measured for a capture (#2660). The reader is the only place a wire
 // fact becomes a daemon fact, so it owns the whole strictness budget: what cannot be placed is
 // restated as `unmeasurable` with a reason, never as a band and never as silence.
diff --git a/scripts/check-affected/model.ts b/scripts/check-affected/model.ts
index d21e10de21..259e53fb68 100644
--- a/scripts/check-affected/model.ts
+++ b/scripts/check-affected/model.ts
@@ -453,7 +453,9 @@ const BUILD_OWNERSHIP: ReadonlyArray<{
     owns: (file) =>
       file.startsWith('packages/capture-kit/src/ios-snapshot-engine/') ||
       file.startsWith('apple/snapshot-presentation/') ||
-      file === 'contracts/fixtures/ios-snapshot-engine-conformance.json',
+      file === 'packages/kernel/src/rect.ts' ||
+      file === 'contracts/fixtures/ios-snapshot-engine-conformance.json' ||
+      file === 'contracts/fixtures/snapshot-actionability-policy.json',
   },
   // Both platform builds compile the same runner sources, and each is a separate
   // gate in a separate lane, so a Swift change owns both.
diff --git a/scripts/ios-snapshot-differential.test.ts b/scripts/ios-snapshot-differential.test.ts
index a8c8d30414..60f3fdf8bc 100644
--- a/scripts/ios-snapshot-differential.test.ts
+++ b/scripts/ios-snapshot-differential.test.ts
@@ -1,6 +1,10 @@
 import assert from 'node:assert/strict';
+import fs from 'node:fs';
+import path from 'node:path';
 import { test } from 'node:test';
 import fc from 'fast-check';
+import { isGeometricallyActionable, isPositiveFiniteRect } from '@agent-device/kernel/rect';
+import type { Rect } from '@agent-device/kernel/snapshot';
 import {
   compareDifferentialCases,
   swiftToolchainAvailable,
@@ -124,3 +128,107 @@ function assertWithinKillCriterion(startedAt: number, seed: number): void {
       String(seed),
   );
 }
+
+type ActionabilityRect = Readonly<{ x: number; y: number; width: number; height: number }>;
+type ActionabilityUnusableRect = Readonly<{ infinite: true }> | Readonly<{ nonFinite: true }>;
+type ActionabilityViewport =
+  | Readonly<{ kind: 'reported' | 'derived'; rect: ActionabilityRect }>
+  | Readonly<{ kind: 'missing'; reason: 'not-provided' | 'invalid' }>;
+type ActionabilityVector = Readonly<{
+  name: string;
+  swift: boolean;
+  typescript: boolean;
+  asymmetry?: string;
+  enabled: boolean;
+  node: ActionabilityRect | ActionabilityUnusableRect;
+  viewport: ActionabilityViewport;
+  /** `null` is the absent bit. */
+  hittable: boolean | null;
+  nodeRectGuardPasses: boolean;
+}>;
+
+const ACTIONABILITY_POLICY_PATH = path.resolve(
+  import.meta.dirname,
+  '..',
+  'contracts',
+  'fixtures',
+  'snapshot-actionability-policy.json',
+);
+
+/** A box whose components are not numbers anything may plot. JSON has no literal for infinity. */
+const NON_FINITE_RECT: Rect = {
+  x: Number.NEGATIVE_INFINITY,
+  y: Number.NEGATIVE_INFINITY,
+  width: Number.POSITIVE_INFINITY,
+  height: Number.POSITIVE_INFINITY,
+};
+
+function declaresItsAsymmetry(vector: ActionabilityVector): boolean {
+  const hasReason = typeof vector.asymmetry === 'string' && vector.asymmetry.length > 0;
+  return (vector.swift && vector.typescript) !== hasReason;
+}
+
+function readActionabilityVectors(): readonly ActionabilityVector[] {
+  const table = JSON.parse(fs.readFileSync(ACTIONABILITY_POLICY_PATH, 'utf8')) as {
+    cases: readonly ActionabilityVector[];
+  };
+  assert.ok(table.cases.length > 0, 'actionability vector table must not be empty');
+  assert.equal(
+    new Set(table.cases.map((vector) => vector.name)).size,
+    table.cases.length,
+    'actionability vector names must be unique',
+  );
+  for (const vector of table.cases) {
+    assert.equal(typeof vector.swift, 'boolean', `${vector.name}: row must declare the Swift side`);
+    assert.equal(
+      typeof vector.typescript,
+      'boolean',
+      `${vector.name}: row must declare the TypeScript side`,
+    );
+    assert.ok(
+      declaresItsAsymmetry(vector),
+      `${vector.name}: a row both languages do not share must name the asymmetry`,
+    );
+  }
+  return table.cases;
+}
+
+function toRect(node: ActionabilityVector['node']): Rect {
+  if ('nonFinite' in node) return NON_FINITE_RECT;
+  if ('infinite' in node) {
+    throw new Error(
+      "CGRect.infinite is Apple's value and no row reaching TypeScript may stand for it: " +
+        'that row belongs to the Swift side alone',
+    );
+  }
+  return node;
+}
+
+// The Swift twin of these rows is ActionabilityPolicyTests, run by `swift test --package-path
+// apple/snapshot-presentation` in this same command.
+test('the shared hittable predicate agrees with every golden actionability vector', () => {
+  for (const vector of readActionabilityVectors().filter((row) => row.typescript)) {
+    const node = toRect(vector.node);
+    assert.equal(
+      isPositiveFiniteRect(node),
+      vector.nodeRectGuardPasses,
+      `${vector.name}: node-rect guard`,
+    );
+    if (vector.viewport.kind === 'missing') {
+      throw new Error(`${vector.name}: the TypeScript predicate takes a box`);
+    }
+    assert.equal(
+      isGeometricallyActionable(vector.enabled, node, vector.viewport.rect),
+      vector.hittable,
+      vector.name,
+    );
+  }
+});
+
+test('the TypeScript rows cover every viewport kind that carries a box', () => {
+  const vectors = readActionabilityVectors().filter((row) => row.typescript);
+  assert.deepEqual([...new Set(vectors.map((vector) => vector.viewport.kind))].sort(), [
+    'derived',
+    'reported',
+  ]);
+});