Fix MCP identifiers and detail reads for SwiftUI virtual nodes

LookInside.xcodeproj/project.pbxproj

@@ -191,6 +191,7 @@
 				MCPBridge/MCPBridgeAttributeValueDecoder.swift,
 				MCPBridge/MCPBridgeConnection.swift,
 				MCPBridge/MCPBridgeDetailsService.swift,
+				MCPBridge/MCPBridgeDisplayItemAccess.swift,
 				MCPBridge/MCPBridgeEventPublisher.swift,
 				MCPBridge/MCPBridgeFrame.swift,
 				MCPBridge/MCPBridgeInspectionModels.swift,

LookInside/MCPBridge/MCPBridgeDetailsService.swift

@@ -28,8 +28,8 @@
 import AppKit
 import CoreGraphics
 import Foundation
-import os
 import FoundationToolbox
+import os
 
 @Loggable(subsystem: "com.lookinside.app", category: "MCPBridge.Details")
 @MainActor
@@ -40,7 +40,6 @@ final class MCPBridgeDetailsService {
     /// need more issue multiple calls.
     private static let maximumObjectIdentifiersPerCall = 100
 
-
     init() {}
 
     // MARK: - Entry point
@@ -82,9 +81,8 @@ final class MCPBridgeDetailsService {
         case let .success(parsed):
             requestedIdentifiers = parsed.identifiers
             if parsed.droppedDuplicateCount > 0 {
-                #log(.debug, 
-                    "details.read collapsed \(parsed.droppedDuplicateCount, privacy: .public) duplicate object identifier(s)"
-                )
+                #log(.debug,
+                     "details.read collapsed \(parsed.droppedDuplicateCount, privacy: .public) duplicate object identifier(s)")
             }
         case .failure(.notAllStrings), .failure(.empty):
             return .failure(identifier: identifier, error: .invalidParameters)
@@ -98,11 +96,10 @@ final class MCPBridgeDetailsService {
             )
         }
 
-        let includeUserCustom: Bool
-        if case let .bool(raw)? = parameters["includeUserCustom"] {
-            includeUserCustom = raw
+        let includeUserCustom: Bool = if case let .bool(raw)? = parameters["includeUserCustom"] {
+            raw
         } else {
-            includeUserCustom = true
+            true
         }
 
         // Live-document lookup
@@ -134,24 +131,42 @@ final class MCPBridgeDetailsService {
         var resolvedItems: [(identifier: String, displayItem: DisplayItem, nativeOid: UInt)] = []
         resolvedItems.reserveCapacity(requestedIdentifiers.count)
         var failedIdentifiers: [String] = []
+        var emittedDetails: [MCPBridgeViewDetail] = []
 
         for requested in requestedIdentifiers {
             guard let displayItem = MCPBridgeLiveDocumentLookup.findDisplayItem(
                 amongRoots: roots,
                 matchingObjectIdentifier: requested
-            ),
-                case let nativeOid = displayItem.detailRequestOid,
-                nativeOid != 0
-            else {
+            ) else {
                 failedIdentifiers.append(requested)
                 continue
             }
-            resolvedItems.append((identifier: requested, displayItem: displayItem, nativeOid: nativeOid))
+            let nativeOid = displayItem.detailRequestOid
+            if displayItem.customInfo != nil, nativeOid == 0 {
+                // Older Servers send virtual-node attributes with the tree.
+                // They have no object for RPC 203; return that inline detail.
+                if displayItem.customAttrGroupList == nil {
+                    displayItem.customAttrGroupList = []
+                }
+                emittedDetails.append(encodeDetail(
+                    identifier: requested, displayItem: displayItem,
+                    inbuiltGroups: displayItem.attributesGroupList,
+                    customGroups: displayItem.customAttrGroupList,
+                    includeUserCustom: includeUserCustom
+                ))
+            } else if nativeOid != 0 {
+                resolvedItems.append((identifier: requested, displayItem: displayItem, nativeOid: nativeOid))
+            } else {
+                failedIdentifiers.append(requested)
+            }
         }
 
         // If everything is gone, surface a structured error instead of
         // an empty success response — the agent likely passed stale oids.
         if resolvedItems.isEmpty {
+            if !emittedDetails.isEmpty {
+                return successResponse(identifier: identifier, details: emittedDetails, failedIdentifiers: failedIdentifiers)
+            }
             return .failure(
                 identifier: identifier,
                 error: MCPBridgeErrorPayload(
@@ -215,8 +230,7 @@ final class MCPBridgeDetailsService {
         // to its owning document.
         let staticDataSource = document.hierarchyDataSource
 
-        var emittedDetails: [MCPBridgeViewDetail] = []
-        emittedDetails.reserveCapacity(allDetails.count)
+        emittedDetails.reserveCapacity(emittedDetails.count + allDetails.count)
         var seenOids: Set<UInt> = []
 
         for detail in allDetails {
@@ -246,40 +260,11 @@ final class MCPBridgeDetailsService {
             // Encode the attribute groups carried in this detail
             // through the read-side encoder so the wire shape matches
             // attributes.read.
-            let redactSecureContent = MCPBridgeSecureContentDetector.isSecure(displayItem: resolved.displayItem)
-            var rawGroups: [AttributesGroup] = []
-            if let inbuiltGroups = detail.attributesGroupList {
-                rawGroups.append(contentsOf: inbuiltGroups)
-            }
-            if includeUserCustom, let customGroups = detail.customAttrGroupList {
-                rawGroups.append(contentsOf: customGroups)
-            }
-            let encodedGroups = rawGroups.map { group -> MCPBridgeAttributeGroup in
-                let sections = (group.attrSections ?? []).map { section -> MCPBridgeAttributeSection in
-                    let attributes = (section.attributes ?? []).map { attribute in
-                        MCPBridgeAttributeEncoder.encode(
-                            attribute,
-                            redactingSecureContent: redactSecureContent
-                        )
-                    }
-                    return MCPBridgeAttributeSection(
-                        identifier: section.identifier ?? "",
-                        attributes: attributes
-                    )
-                }
-                let groupIdentifier = group.userCustomTitle ?? group.identifier ?? ""
-                return MCPBridgeAttributeGroup(
-                    identifier: groupIdentifier,
-                    isUserCustom: group.userCustomTitle != nil,
-                    isSwiftUIGroup: group.isSwiftUIGroup,
-                    sections: sections
-                )
-            }
-
-            emittedDetails.append(MCPBridgeViewDetail(
-                objectIdentifier: resolved.identifier,
-                groups: encodedGroups,
-                secureContent: redactSecureContent
+            emittedDetails.append(encodeDetail(
+                identifier: resolved.identifier, displayItem: resolved.displayItem,
+                inbuiltGroups: detail.attributesGroupList,
+                customGroups: detail.customAttrGroupList,
+                includeUserCustom: includeUserCustom
             ))
         }
 
@@ -299,6 +284,33 @@ final class MCPBridgeDetailsService {
 
     // MARK: - Helpers
 
+    private func encodeDetail(
+        identifier: String,
+        displayItem: DisplayItem,
+        inbuiltGroups: [AttributesGroup]?,
+        customGroups: [AttributesGroup]?,
+        includeUserCustom: Bool
+    ) -> MCPBridgeViewDetail {
+        let redact = MCPBridgeSecureContentDetector.isSecure(displayItem: displayItem)
+        let groups = (inbuiltGroups ?? []) + (includeUserCustom ? customGroups ?? [] : [])
+        let encoded = groups.map { group in
+            MCPBridgeAttributeGroup(
+                identifier: group.userCustomTitle ?? group.identifier ?? "",
+                isUserCustom: group.userCustomTitle != nil,
+                isSwiftUIGroup: group.isSwiftUIGroup,
+                sections: (group.attrSections ?? []).map { section in
+                    MCPBridgeAttributeSection(
+                        identifier: section.identifier ?? "",
+                        attributes: (section.attributes ?? []).map {
+                            MCPBridgeAttributeEncoder.encode($0, redactingSecureContent: redact)
+                        }
+                    )
+                }
+            )
+        }
+        return MCPBridgeViewDetail(objectIdentifier: identifier, groups: encoded, secureContent: redact)
+    }
+
     private func successResponse(
         identifier: String,
         details: [MCPBridgeViewDetail],

LookInside/MCPBridge/MCPBridgeDisplayItemAccess.swift

@@ -0,0 +1,41 @@
+import Foundation
+
+/// Identifiers belong to a hierarchy snapshot. A virtual node is addressable
+/// even when it has no UIView/CALayer and an older Server sent details inline.
+@MainActor
+enum MCPBridgeDisplayItemAccess {
+    static func objectIdentifier(for item: DisplayItem) -> String {
+        if let customInfo = item.customInfo {
+            if customInfo.detailObjectOid != 0 {
+                return "0x" + String(customInfo.detailObjectOid, radix: 16)
+            }
+            if let identifier = customInfo.swiftUIDisplayItemID, !identifier.isEmpty {
+                return identifier
+            }
+        } else if let oid = item.displayingObject()?.oid, oid != 0 {
+            return "0x" + String(oid, radix: 16)
+        }
+        // Generic custom nodes predate deferred detail IDs. Keep their
+        // host-local identity in a namespace separate from target object IDs.
+        let address = UInt(bitPattern: Unmanaged.passUnretained(item).toOpaque())
+        return "custom:0x" + String(address, radix: 16)
+    }
+
+    static func find(in roots: [DisplayItem], identifier: String) -> DisplayItem? {
+        var queue = roots
+        var index = 0
+        while index < queue.count {
+            let item = queue[index]
+            index += 1
+            if objectIdentifier(for: item) == identifier {
+                return item
+            }
+            queue.append(contentsOf: item.subitems ?? [])
+        }
+        return nil
+    }
+
+    static func hasCachedDetails(_ item: DisplayItem) -> Bool {
+        item.attributesGroupList != nil || item.customAttrGroupList != nil
+    }
+}

LookInside/MCPBridge/MCPBridgeInspectionModels.swift

@@ -82,8 +82,8 @@ struct MCPBridgeTargetInfo: Sendable, Codable {
 /// screenshot URIs live in separate methods to be added in subsequent
 /// commits.
 struct MCPBridgeViewNode: Sendable, Codable {
-    /// Hex-encoded `InspectedObject.oid`, prefixed with `0x` (for example,
-    /// `0x600000abc123`). Stable within a single connected app instance.
+    /// Opaque handle: a hex native/deferred-detail oid, or a namespaced
+    /// virtual-node handle for older SDKs. Rediscover after hierarchy refresh.
     let objectIdentifier: String
 
     /// Leaf Objective-C class name (head of `InspectedObject.classChainList`),

LookInside/MCPBridge/MCPBridgeInspectionService.swift

@@ -297,7 +297,7 @@ final class MCPBridgeInspectionService {
             // see an empty `groups` array fetch the details with
             // `read_view_details` (the `details.read` route). `secureContent`
             // tells the agent why textual values may be `null` here.
-            let hasCachedDetails = displayItem.attributesGroupList?.isEmpty == false
+            let hasCachedDetails = MCPBridgeDisplayItemAccess.hasCachedDetails(displayItem)
             return .success(
                 identifier: identifier,
                 result: .object([

LookInside/MCPBridge/MCPBridgeLiveDocumentLookup.swift

@@ -2,11 +2,8 @@
 //
 // Shared lookup helpers that translate the bridge wire identifiers
 // (`targetIdentifier`, `objectIdentifier`) into the host's live runtime
-// objects (`LiveDocument`, `DisplayItem`). Both the inspection
-// service (read-only queries) and the invocation service (round-trips to
-// the server over the connection channel) share this surface so the wire shape — hex
-// `oid` strings, decimal `appInfoIdentifier` strings — stays one
-// canonical implementation.
+// objects (`LiveDocument`, `DisplayItem`). The services share one canonical
+// implementation for native and virtual node handles and decimal target IDs.
 //
 // All entry points are `@MainActor`: `NSDocumentController` and
 // `LiveDocument` require main-thread isolation, and the bridge
@@ -39,23 +36,12 @@ enum MCPBridgeLiveDocumentLookup {
 
     /// Breadth-first search across the supplied root display items for an
     /// item whose wire `objectIdentifier` matches `identifier`. The wire
-    /// form is the hex-encoded `InspectedObject.oid`, prefixed with `0x`
-    /// (e.g. `0x600000abc123`).
+    /// form is an opaque native or virtual node handle returned by this bridge.
     static func findDisplayItem(
         amongRoots roots: [DisplayItem],
         matchingObjectIdentifier identifier: String
     ) -> DisplayItem? {
-        var queue: [DisplayItem] = roots
-        while queue.isEmpty == false {
-            let current = queue.removeFirst()
-            if objectIdentifierString(for: current) == identifier {
-                return current
-            }
-            if let subitems = current.subitems {
-                queue.append(contentsOf: subitems)
-            }
-        }
-        return nil
+        MCPBridgeDisplayItemAccess.find(in: roots, identifier: identifier)
     }
 
     /// Top-level display items (windows / scenes) inside a live document.
@@ -72,12 +58,11 @@ enum MCPBridgeLiveDocumentLookup {
         return flatItems.filter { $0.indentLevel() == 0 }
     }
 
-    /// Canonical hex-encoded `objectIdentifier` string for a display item.
+    /// Canonical `objectIdentifier` for native and virtual display items.
     /// Stays in sync with the form returned by `hierarchy.read` so
     /// callers can round-trip identifiers across bridge methods.
     static func objectIdentifierString(for item: DisplayItem) -> String {
-        let oid = item.displayingObject()?.oid ?? 0
-        return String(format: "0x%lx", oid)
+        MCPBridgeDisplayItemAccess.objectIdentifier(for: item)
     }
 
     /// The item's rectangle in the root coordinate space.
@@ -93,6 +78,6 @@ enum MCPBridgeLiveDocumentLookup {
     /// both values are equally meaningless and the raw one at least matches
     /// what the host inspector displays.
     static func rootSpaceFrame(for item: DisplayItem) -> CGRect {
-        return item.hasValidFrameToRoot() ? item.calculateFrameToRoot() : item.frame
+        item.hasValidFrameToRoot() ? item.calculateFrameToRoot() : item.frame
     }
 }

Scripts/test-mcp-bridge.sh

@@ -42,4 +42,25 @@ RECOVERY_HINT_TEST="$ROOT/Tests/MCPBridge/MCPBridgeRecoveryHintTests.swift"
 swiftc -parse-as-library "$RECOVERY_HINT" "$RECOVERY_HINT_TEST" -o "$TMPDIR/recovery-hint-test"
 "$TMPDIR/recovery-hint-test"
 
+# Exercise virtual-node identity against the real wire model. Only the C
+# declarations are imported; Swift model implementations compile alongside it.
+CORE="$ROOT/Sources/LookinCore"
+SERVER_BASE="$ROOT/Sources/LookinServerBase"
+mkdir -p "$TMPDIR/core"
+for source_file in "$CORE"/*.m "$CORE"/Shim/*.m "$SERVER_BASE"/*.m; do
+	[ -e "$source_file" ] || continue
+	xcrun clang -c -fobjc-arc -w -DSHOULD_COMPILE_LOOKIN_SERVER=1 \
+		-mmacosx-version-min=14.0 -I "$CORE" -I "$CORE/include" -I "$SERVER_BASE" \
+		"$source_file" -o "$TMPDIR/core/$(basename "$source_file" .m).o"
+done
+swiftc -parse-as-library -target "$(uname -m)-apple-macos14.0" \
+	-import-objc-header "$ROOT/Tests/Dashboard/LKDashboardTests-Bridging-Header.h" \
+	-Xcc -DSHOULD_COMPILE_LOOKIN_SERVER=1 -D SHOULD_COMPILE_LOOKIN_SERVER -D LOOKIN_CORE_STANDALONE \
+	-Xcc -I"$CORE" -Xcc -I"$CORE/include" -Xcc -I"$SERVER_BASE" \
+	$(find "$ROOT/Sources/LookinCoreImpl" -name '*.swift' -type f | sort) \
+	"$ROOT/LookInside/MCPBridge/MCPBridgeDisplayItemAccess.swift" \
+	"$ROOT/Tests/MCPBridge/MCPBridgeDisplayItemAccessTests.swift" \
+	"$TMPDIR"/core/*.o -framework AppKit -framework QuartzCore -o "$TMPDIR/display-item-test"
+"$TMPDIR/display-item-test"
+
 echo "MCPBridge tests passed"