diff --git a/apps/.i18n/native-source.json b/apps/.i18n/native-source.json
index 7aff760b5006..79e654bc4cfe 100644
--- a/apps/.i18n/native-source.json
+++ b/apps/.i18n/native-source.json
@@ -37475,7 +37475,7 @@
     },
     {
       "kind": "conditional-branch",
-      "line": 554,
+      "line": 555,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatMessageViews.swift",
       "source": "Voice note",
       "surface": "apple",
@@ -37483,7 +37483,7 @@
     },
     {
       "kind": "ui-call",
-      "line": 599,
+      "line": 600,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatMessageViews.swift",
       "source": "Writing",
       "surface": "apple",
@@ -37491,7 +37491,7 @@
     },
     {
       "kind": "ui-call",
-      "line": 625,
+      "line": 626,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatMessageViews.swift",
       "source": "Preparing audio…",
       "surface": "apple",
@@ -37499,7 +37499,7 @@
     },
     {
       "kind": "ui-call",
-      "line": 628,
+      "line": 629,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatMessageViews.swift",
       "source": "Speaking…",
       "surface": "apple",
@@ -37507,7 +37507,7 @@
     },
     {
       "kind": "conditional-branch",
-      "line": 636,
+      "line": 637,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatMessageViews.swift",
       "source": "Preparing audio, tap to cancel",
       "surface": "apple",
@@ -37515,7 +37515,7 @@
     },
     {
       "kind": "conditional-branch",
-      "line": 637,
+      "line": 638,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatMessageViews.swift",
       "source": "Speaking, tap to stop",
       "surface": "apple",
@@ -38611,7 +38611,7 @@
     },
     {
       "kind": "ui-localized-call",
-      "line": 80,
+      "line": 83,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatToolActivityViews.swift",
       "source": "Running",
       "surface": "apple",
@@ -38619,7 +38619,7 @@
     },
     {
       "kind": "conditional-branch",
-      "line": 129,
+      "line": 133,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatToolActivityViews.swift",
       "source": "Collapse tool result",
       "surface": "apple",
@@ -38627,7 +38627,7 @@
     },
     {
       "kind": "conditional-branch",
-      "line": 129,
+      "line": 133,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatToolActivityViews.swift",
       "source": "Expand tool result",
       "surface": "apple",
@@ -38635,7 +38635,7 @@
     },
     {
       "kind": "ui-localized-call",
-      "line": 165,
+      "line": 169,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatToolActivityViews.swift",
       "source": "Show less",
       "surface": "apple",
@@ -38643,7 +38643,7 @@
     },
     {
       "kind": "ui-localized-call",
-      "line": 167,
+      "line": 171,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatToolActivityViews.swift",
       "source": "Show all %lld lines",
       "surface": "apple",
@@ -38651,7 +38651,7 @@
     },
     {
       "kind": "ui-call",
-      "line": 256,
+      "line": 272,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatToolActivityViews.swift",
       "source": "Collapsed",
       "surface": "apple",
@@ -38659,7 +38659,7 @@
     },
     {
       "kind": "conditional-branch",
-      "line": 1347,
+      "line": 1377,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatTranscriptCache.swift",
       "source": "INSERT INTO cached_transcripts(gateway_id, session_key, agent_id, payload, updated_at)\nSELECT gateway_id, session_key, agent_id, payload, updated_at\nFROM cached_transcripts_pre_v3",
       "surface": "apple",
@@ -38667,7 +38667,7 @@
     },
     {
       "kind": "conditional-branch",
-      "line": 1352,
+      "line": 1382,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatTranscriptCache.swift",
       "source": "INSERT INTO cached_transcripts(gateway_id, session_key, agent_id, payload, updated_at)\nSELECT gateway_id, session_key, '', payload, updated_at\nFROM cached_transcripts_pre_v3\nWHERE lower(trim(session_key)) GLOB 'agent:*:*'",
       "surface": "apple",
@@ -38747,7 +38747,7 @@
     },
     {
       "kind": "ui-call",
-      "line": 1083,
+      "line": 1085,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatView.swift",
       "source": "Copy Message",
       "surface": "apple",
@@ -38755,7 +38755,7 @@
     },
     {
       "kind": "ui-call",
-      "line": 1106,
+      "line": 1108,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatView.swift",
       "source": "Open Full Message",
       "surface": "apple",
@@ -38763,7 +38763,7 @@
     },
     {
       "kind": "ui-call",
-      "line": 1125,
+      "line": 1127,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatView.swift",
       "source": "Rewind to Here",
       "surface": "apple",
@@ -38771,7 +38771,7 @@
     },
     {
       "kind": "ui-call",
-      "line": 1145,
+      "line": 1147,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatView.swift",
       "source": "Fork from Here",
       "surface": "apple",
@@ -38779,7 +38779,7 @@
     },
     {
       "kind": "ui-localized-call",
-      "line": 1173,
+      "line": 1175,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatView.swift",
       "source": "Reply",
       "surface": "apple",
@@ -38787,7 +38787,7 @@
     },
     {
       "kind": "ui-localized-call",
-      "line": 1183,
+      "line": 1185,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatView.swift",
       "source": "You",
       "surface": "apple",
@@ -38795,7 +38795,7 @@
     },
     {
       "kind": "ui-localized-call",
-      "line": 1185,
+      "line": 1187,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatView.swift",
       "source": "Assistant",
       "surface": "apple",
@@ -38803,7 +38803,7 @@
     },
     {
       "kind": "ui-call",
-      "line": 1251,
+      "line": 1253,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatView.swift",
       "source": "Loading chat",
       "surface": "apple",
@@ -38811,7 +38811,7 @@
     },
     {
       "kind": "ui-modifier",
-      "line": 1331,
+      "line": 1333,
       "path": "apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatView.swift",
       "source": "Dismiss",
       "surface": "apple",
diff --git a/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatMessageViews.swift b/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatMessageViews.swift
index f423f260153c..c7db8e70cff1 100644
--- a/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatMessageViews.swift
+++ b/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatMessageViews.swift
@@ -395,6 +395,7 @@ private struct ChatMessageBody: View {
                 arguments: nil,
                 details: self.message.details,
                 resultText: self.primaryText,
+                isError: self.message.isError ?? false,
                 isPending: false)]
         }
         guard self.message.role.lowercased() == "assistant" else { return [] }
@@ -813,6 +814,7 @@ struct ChatPendingToolsBubble: View {
                 arguments: call.args,
                 details: nil,
                 resultText: nil,
+                isError: false,
                 isPending: true)
         }
     }
diff --git a/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatModels.swift b/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatModels.swift
index 24881ac6334b..d5362383c0d1 100644
--- a/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatModels.swift
+++ b/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatModels.swift
@@ -125,6 +125,7 @@ public struct OpenClawChatMessageContent: Codable, Hashable, Sendable {
     public let name: String?
     public let arguments: AnyCodable?
     public let details: AnyCodable?
+    public let isError: Bool?
 
     public init(
         type: String?,
@@ -139,7 +140,8 @@ public struct OpenClawChatMessageContent: Codable, Hashable, Sendable {
         id: String? = nil,
         name: String? = nil,
         arguments: AnyCodable? = nil,
-        details: AnyCodable? = nil)
+        details: AnyCodable? = nil,
+        isError: Bool? = nil)
     {
         self.type = type
         self.text = text
@@ -154,6 +156,7 @@ public struct OpenClawChatMessageContent: Codable, Hashable, Sendable {
         self.name = name
         self.arguments = arguments
         self.details = details
+        self.isError = isError
     }
 
     enum CodingKeys: String, CodingKey {
@@ -170,6 +173,8 @@ public struct OpenClawChatMessageContent: Codable, Hashable, Sendable {
         case name
         case arguments
         case details
+        case isError
+        case is_error
     }
 
     public init(from decoder: Decoder) throws {
@@ -185,6 +190,8 @@ public struct OpenClawChatMessageContent: Codable, Hashable, Sendable {
         self.name = try container.decodeIfPresent(String.self, forKey: .name)
         self.arguments = try container.decodeIfPresent(AnyCodable.self, forKey: .arguments)
         self.details = try container.decodeIfPresent(AnyCodable.self, forKey: .details)
+        self.isError = try container.decodeIfPresent(Bool.self, forKey: .isError) ??
+            container.decodeIfPresent(Bool.self, forKey: .is_error)
         self.preview = try container.decodeIfPresent(OpenClawChatCanvasPreview.self, forKey: .preview)
 
         if let any = try container.decodeIfPresent(AnyCodable.self, forKey: .content) {
@@ -195,6 +202,24 @@ public struct OpenClawChatMessageContent: Codable, Hashable, Sendable {
             self.content = nil
         }
     }
+
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.container(keyedBy: CodingKeys.self)
+        try container.encodeIfPresent(self.type, forKey: .type)
+        try container.encodeIfPresent(self.text, forKey: .text)
+        try container.encodeIfPresent(self.thinking, forKey: .thinking)
+        try container.encodeIfPresent(self.thinkingSignature, forKey: .thinkingSignature)
+        try container.encodeIfPresent(self.mimeType, forKey: .mimeType)
+        try container.encodeIfPresent(self.fileName, forKey: .fileName)
+        try container.encodeIfPresent(self.durationSeconds, forKey: .durationSeconds)
+        try container.encodeIfPresent(self.content, forKey: .content)
+        try container.encodeIfPresent(self.preview, forKey: .preview)
+        try container.encodeIfPresent(self.id, forKey: .id)
+        try container.encodeIfPresent(self.name, forKey: .name)
+        try container.encodeIfPresent(self.arguments, forKey: .arguments)
+        try container.encodeIfPresent(self.details, forKey: .details)
+        try container.encodeIfPresent(self.isError, forKey: .isError)
+    }
 }
 
 public struct OpenClawChatCanvasPreview: Codable, Hashable, Sendable {
@@ -243,6 +268,7 @@ public struct OpenClawChatMessage: Codable, Hashable, Identifiable, Sendable {
     public let stopReason: String?
     public let errorMessage: String?
     public let details: AnyCodable?
+    public let isError: Bool?
 
     enum CodingKeys: String, CodingKey {
         case role
@@ -258,6 +284,8 @@ public struct OpenClawChatMessage: Codable, Hashable, Identifiable, Sendable {
         case stopReason
         case errorMessage
         case details
+        case isError
+        case is_error
         case mediaPath = "MediaPath"
         case mediaPaths = "MediaPaths"
         case mediaType = "MediaType"
@@ -277,7 +305,8 @@ public struct OpenClawChatMessage: Codable, Hashable, Identifiable, Sendable {
         usage: OpenClawChatUsage? = nil,
         stopReason: String? = nil,
         errorMessage: String? = nil,
-        details: AnyCodable? = nil)
+        details: AnyCodable? = nil,
+        isError: Bool? = nil)
     {
         self.id = id
         self.transcriptMessageID = transcriptMessageID
@@ -292,6 +321,7 @@ public struct OpenClawChatMessage: Codable, Hashable, Identifiable, Sendable {
         self.stopReason = stopReason
         self.errorMessage = errorMessage
         self.details = details
+        self.isError = isError
     }
 
     public init(from decoder: Decoder) throws {
@@ -311,6 +341,8 @@ public struct OpenClawChatMessage: Codable, Hashable, Identifiable, Sendable {
         let decodedStopReason = try container.decodeIfPresent(String.self, forKey: .stopReason)
         let decodedErrorMessage = try container.decodeIfPresent(String.self, forKey: .errorMessage)
         let decodedDetails = try container.decodeIfPresent(AnyCodable.self, forKey: .details)
+        let decodedIsError = try container.decodeIfPresent(Bool.self, forKey: .isError) ??
+            container.decodeIfPresent(Bool.self, forKey: .is_error)
 
         self.role = decodedRole
         self.transcriptMessageID = decodedOpenClaw?.id
@@ -322,6 +354,7 @@ public struct OpenClawChatMessage: Codable, Hashable, Identifiable, Sendable {
         self.stopReason = decodedStopReason
         self.errorMessage = decodedErrorMessage
         self.details = decodedDetails
+        self.isError = decodedIsError
 
         let decodedContent: [OpenClawChatMessageContent] = if let decoded = try? container.decode(
             [OpenClawChatMessageContent].self,
@@ -432,6 +465,7 @@ public struct OpenClawChatMessage: Codable, Hashable, Identifiable, Sendable {
         try container.encodeIfPresent(self.stopReason, forKey: .stopReason)
         try container.encodeIfPresent(self.errorMessage, forKey: .errorMessage)
         try container.encodeIfPresent(self.details, forKey: .details)
+        try container.encodeIfPresent(self.isError, forKey: .isError)
         try container.encode(self.content, forKey: .content)
     }
 }
diff --git a/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatToolActivityViews.swift b/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatToolActivityViews.swift
index a95a66ed745f..321280a381bd 100644
--- a/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatToolActivityViews.swift
+++ b/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatToolActivityViews.swift
@@ -11,6 +11,7 @@ struct ChatToolActivityItem: Identifiable, Equatable {
     let arguments: AnyCodable?
     let details: AnyCodable?
     let resultText: String?
+    let isError: Bool
     let isPending: Bool
 }
 
@@ -32,6 +33,7 @@ enum ChatToolActivity {
                 arguments: call.arguments,
                 details: result?.details,
                 resultText: result?.text,
+                isError: result?.isError ?? false,
                 isPending: false)
         }
 
@@ -42,6 +44,7 @@ enum ChatToolActivity {
                 arguments: nil,
                 details: result.details,
                 resultText: result.text,
+                isError: result.isError ?? false,
                 isPending: false)
         })
         return items
@@ -108,7 +111,8 @@ struct ChatToolActivityRow: View {
         self.resolvedDiff = ChatToolDiff.resolveDiff(
             name: item.name,
             arguments: item.arguments,
-            details: item.details)
+            details: item.details,
+            isError: item.isError)
     }
 
     var body: some View {
@@ -202,11 +206,12 @@ struct ChatToolActivityRow: View {
 
             Image(systemName: Self.symbol(forToolName: self.item.name))
                 .font(.system(size: 12, weight: .medium))
-                .foregroundStyle(.secondary)
+                .foregroundStyle(self.item.isError ? OpenClawChatTheme.danger : Color.secondary)
 
             Text(self.display.title)
                 .font(OpenClawChatTypography.footnoteSemiBold)
-                .foregroundStyle(OpenClawChatTheme.assistantText)
+                .foregroundStyle(
+                    self.item.isError ? OpenClawChatTheme.danger : OpenClawChatTheme.assistantText)
                 .lineLimit(1)
 
             if let detailLine = self.detailLine {
@@ -234,18 +239,29 @@ struct ChatToolActivityRow: View {
     }
 
     private var diffRows: some View {
-        VStack(alignment: .leading, spacing: 0) {
-            ForEach(self.expandedDiffLines.indices, id: \.self) { index in
-                self.diffRow(self.expandedDiffLines[index])
+        // The orthogonal nested scroll keeps long diff lines reachable without
+        // competing with the transcript's vertical gesture.
+        ScrollView(.horizontal, showsIndicators: false) {
+            VStack(alignment: .leading, spacing: 0) {
+                ForEach(self.expandedDiffLines.indices, id: \.self) { index in
+                    self.diffRow(self.expandedDiffLines[index])
+                }
             }
+            .textSelection(.enabled)
         }
         .frame(maxWidth: .infinity, alignment: .leading)
-        .textSelection(.enabled)
     }
 
     @ViewBuilder
     private func diffRow(_ line: ChatToolDiffLine) -> some View {
-        if line.kind == .skip {
+        if line.kind == .file {
+            Text(verbatim: String(line.text.unicodeScalars.prefix(2000)))
+                .font(OpenClawChatTypography.mono(size: 11, relativeTo: .caption))
+                .fontWeight(.semibold)
+                .foregroundStyle(.secondary)
+                .fixedSize(horizontal: true, vertical: false)
+                .padding(.top, 6)
+        } else if line.kind == .skip {
             Text("⋯")
                 .font(OpenClawChatTypography.mono(size: 12, relativeTo: .footnote))
                 .foregroundStyle(.secondary.opacity(0.6))
@@ -267,9 +283,7 @@ struct ChatToolActivityRow: View {
                 Text(verbatim: String(line.text.unicodeScalars.prefix(2000)))
                     .font(OpenClawChatTypography.mono(size: 12, relativeTo: .footnote))
                     .foregroundStyle(self.diffTextColor(line.kind))
-                    .lineLimit(1)
-                    .truncationMode(.tail)
-                    .frame(maxWidth: .infinity, alignment: .leading)
+                    .fixedSize(horizontal: true, vertical: false)
             }
             .background(self.diffBackground(line.kind))
             // Color alone must not carry add/del semantics for assistive tech.
@@ -289,7 +303,7 @@ struct ChatToolActivityRow: View {
             "+ "
         case .del:
             "\u{2212} "
-        case .ctx, .skip:
+        case .ctx, .file, .skip:
             ""
         }
     }
@@ -298,7 +312,7 @@ struct ChatToolActivityRow: View {
         switch kind {
         case .add:
             OpenClawChatTheme.assistantText
-        case .del, .ctx, .skip:
+        case .del, .ctx, .file, .skip:
             .secondary
         }
     }
@@ -309,7 +323,7 @@ struct ChatToolActivityRow: View {
             OpenClawChatTheme.success.opacity(0.14)
         case .del:
             OpenClawChatTheme.danger.opacity(0.12)
-        case .ctx, .skip:
+        case .ctx, .file, .skip:
             .clear
         }
     }
diff --git a/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatToolDiff.swift b/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatToolDiff.swift
index dd5e2df08e33..495666f788bc 100644
--- a/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatToolDiff.swift
+++ b/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatToolDiff.swift
@@ -5,6 +5,7 @@ enum ChatToolDiffLineKind: Equatable, Sendable {
     case add
     case del
     case ctx
+    case file
     case skip
 }
 
@@ -36,6 +37,26 @@ enum ChatToolDiff {
         let truncated: Bool
     }
 
+    private enum PatchOperation {
+        case add
+        case delete
+        case update
+    }
+
+    private struct PatchSection {
+        var operation: PatchOperation
+        let sourcePath: String
+        var path: String
+        var lines: [ChatToolDiffLine] = []
+        var added = 0
+        var removed = 0
+    }
+
+    private struct PatchHunk {
+        var oldLine: Int?
+        var newLine: Int?
+    }
+
     private static let maxInputLines = 600
     private static let maxRenderLines = 400
     private static let maxLocalPairs = 8
@@ -144,11 +165,18 @@ enum ChatToolDiff {
     static func resolveDiff(
         name: String?,
         arguments: AnyCodable?,
-        details: AnyCodable?) -> (lines: [ChatToolDiffLine], stat: ChatToolDiffStat?)?
+        details: AnyCodable?,
+        isError: Bool = false) -> (lines: [ChatToolDiffLine], stat: ChatToolDiffStat?)?
     {
         let normalizedName = name?.trimmingCharacters(in: .whitespacesAndNewlines).lowercased() ?? ""
         let argumentsRecord = arguments?.dictionaryValue
         if self.textEditorToolNames.contains(normalizedName) {
+            if let detailsDiff = self.resolveDetailsDiff(details) {
+                // Applied diff details stay authoritative even when the result reports an error.
+                return detailsDiff
+            }
+            // Failed args describe a proposal, not a mutation known to have been applied.
+            guard !isError else { return nil }
             switch self.string(in: argumentsRecord, keys: ["command"])?
                 .trimmingCharacters(in: .whitespacesAndNewlines)
                 .lowercased()
@@ -167,16 +195,25 @@ enum ChatToolDiff {
         // Plugin tools own their details schema; only edit-family tools may
         // interpret details.diff as a filesystem diff (mirrors the web guard).
         if self.editToolNames.contains(normalizedName) {
-            return self.resolveEditDiff(argumentsRecord, details: details)
+            if let detailsDiff = self.resolveDetailsDiff(details) {
+                return detailsDiff
+            }
+            guard !isError else { return nil }
+            return self.resolveEditDiff(argumentsRecord, details: nil)
         }
         if self.writeToolNames.contains(normalizedName) {
             if let detailsDiff = self.resolveDetailsDiff(details) {
                 return detailsDiff
             }
+            guard !isError else { return nil }
             return self.resolveWriteDiff(argumentsRecord, keys: ["content", "text", "file_text"])
         }
         if self.patchToolNames.contains(normalizedName) {
-            return self.resolveDetailsDiff(details)
+            if let detailsDiff = self.resolveDetailsDiff(details) {
+                return detailsDiff
+            }
+            guard !isError else { return nil }
+            return self.resolvePatchDiff(argumentsRecord)
         }
         return nil
     }
@@ -203,6 +240,232 @@ enum ChatToolDiff {
         return ChatToolDiffLine(kind: kind, lineNo: lineNo, text: String(remainder))
     }
 
+    private static func resolvePatchDiff(
+        _ arguments: [String: AnyCodable]?) -> (lines: [ChatToolDiffLine], stat: ChatToolDiffStat?)?
+    {
+        guard let patch = self.string(in: arguments, keys: ["patch", "input", "diff"]),
+              !patch.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
+        else { return nil }
+
+        let inputClipped = patch.utf16.count > self.maxLocalInputCharacters
+        let text = inputClipped
+            ? String(decoding: patch.utf16.prefix(self.maxLocalInputCharacters), as: UTF16.self)
+            : patch
+        var sections: [PatchSection] = []
+        var current: PatchSection?
+        var hunk = PatchHunk()
+        var storedRows = 0
+        var clipped = inputClipped
+
+        for raw in self.splitLines(text) {
+            let structural = current?.operation == .update
+                ? raw.replacingOccurrences(of: #"[ \t]+$"#, with: "", options: .regularExpression)
+                : raw.trimmingCharacters(in: .whitespaces)
+            if let header = self.patchFileHeader(structural) {
+                if let current { sections.append(current) }
+                current = PatchSection(
+                    operation: header.operation,
+                    sourcePath: header.path,
+                    path: header.path)
+                hunk = PatchHunk()
+                continue
+            }
+            if current?.operation == .update,
+               structural.hasPrefix("*** Move to: "),
+               case let path = String(structural.dropFirst("*** Move to: ".count))
+                   .trimmingCharacters(in: .whitespacesAndNewlines),
+                   !path.isEmpty
+            {
+                current?.path = path
+                continue
+            }
+            if structural == "*** Begin Patch" || structural == "*** End Patch" ||
+                structural == "*** End of File" || structural.hasPrefix("*** Environment ID:")
+            {
+                continue
+            }
+            guard var section = current else { continue }
+
+            if section.operation == .update, raw.hasPrefix("@@") {
+                if !section.lines.isEmpty, section.lines.last?.kind != .skip {
+                    self.pushPatchLine(
+                        ChatToolDiffLine(kind: .skip, text: ""),
+                        section: &section,
+                        storedRows: &storedRows,
+                        clipped: &clipped)
+                }
+                hunk = self.parsePatchHunk(raw)
+            } else if section.operation == .add, raw.hasPrefix("+") {
+                self.pushPatchLine(
+                    ChatToolDiffLine(kind: .add, lineNo: section.added + 1, text: String(raw.dropFirst())),
+                    section: &section,
+                    storedRows: &storedRows,
+                    clipped: &clipped)
+            } else if section.operation == .delete, raw.hasPrefix("-") {
+                self.pushPatchLine(
+                    ChatToolDiffLine(kind: .del, lineNo: section.removed + 1, text: String(raw.dropFirst())),
+                    section: &section,
+                    storedRows: &storedRows,
+                    clipped: &clipped)
+            } else if section.operation == .update,
+                      raw.isEmpty || raw.hasPrefix("+") || raw.hasPrefix("-") || raw.hasPrefix(" ")
+            {
+                self.pushPatchHunkLine(
+                    raw,
+                    hunk: &hunk,
+                    section: &section,
+                    storedRows: &storedRows,
+                    clipped: &clipped)
+            }
+            current = section
+        }
+        if let current { sections.append(current) }
+        return self.finishPatch(sections, clipped: clipped)
+    }
+
+    private static func patchFileHeader(
+        _ raw: String) -> (operation: PatchOperation, path: String)?
+    {
+        let headers: [(String, PatchOperation)] = [
+            ("*** Update File: ", .update),
+            ("*** Add File: ", .add),
+            ("*** Delete File: ", .delete),
+        ]
+        for (prefix, operation) in headers where raw.hasPrefix(prefix) {
+            let path = raw.dropFirst(prefix.count).trimmingCharacters(in: .whitespacesAndNewlines)
+            guard !path.isEmpty else { return nil }
+            return (operation, path)
+        }
+        return nil
+    }
+
+    private static func pushPatchLine(
+        _ line: ChatToolDiffLine,
+        section: inout PatchSection,
+        storedRows: inout Int,
+        clipped: inout Bool)
+    {
+        switch line.kind {
+        case .add:
+            section.added += 1
+        case .del:
+            section.removed += 1
+        case .ctx, .file, .skip:
+            break
+        }
+        if storedRows < self.maxRenderLines {
+            section.lines.append(line)
+            storedRows += 1
+        } else {
+            clipped = true
+        }
+    }
+
+    private static func parsePatchHunk(_ raw: String) -> PatchHunk {
+        guard raw.hasPrefix("@@ -") else { return PatchHunk() }
+        let body = raw.dropFirst(4)
+        guard let plus = body.range(of: " +"),
+              let end = body[plus.upperBound...].range(of: " @@")
+        else { return PatchHunk() }
+        let old = body[..<plus.lowerBound]
+        let new = body[plus.upperBound..<end.lowerBound]
+
+        func line(_ rangeText: Substring) -> Int? {
+            Int(rangeText.split(separator: ",", maxSplits: 1).first ?? "")
+        }
+        guard let oldLine = line(old), let newLine = line(new) else { return PatchHunk() }
+        return PatchHunk(oldLine: oldLine, newLine: newLine)
+    }
+
+    private static func pushPatchHunkLine(
+        _ raw: String,
+        hunk: inout PatchHunk,
+        section: inout PatchSection,
+        storedRows: inout Int,
+        clipped: inout Bool)
+    {
+        let kind: ChatToolDiffLineKind
+        let lineNo: Int?
+        if raw.hasPrefix("+") {
+            kind = .add
+            lineNo = hunk.newLine
+            if let newLine = hunk.newLine {
+                hunk.newLine = newLine + 1
+            }
+        } else if raw.hasPrefix("-") {
+            kind = .del
+            lineNo = hunk.oldLine
+            if let oldLine = hunk.oldLine {
+                hunk.oldLine = oldLine + 1
+            }
+        } else {
+            kind = .ctx
+            lineNo = hunk.newLine
+            if let oldLine = hunk.oldLine, let newLine = hunk.newLine {
+                hunk.oldLine = oldLine + 1
+                hunk.newLine = newLine + 1
+            }
+        }
+        self.pushPatchLine(
+            ChatToolDiffLine(kind: kind, lineNo: lineNo, text: raw.isEmpty ? "" : String(raw.dropFirst())),
+            section: &section,
+            storedRows: &storedRows,
+            clipped: &clipped)
+    }
+
+    private static func finishPatch(
+        _ sections: [PatchSection],
+        clipped initialClipped: Bool) -> (lines: [ChatToolDiffLine], stat: ChatToolDiffStat?)?
+    {
+        guard !sections.isEmpty else { return nil }
+
+        var lines: [ChatToolDiffLine] = []
+        var clipped = initialClipped
+        let hasHeaderOnlyDelete = sections.contains { section in
+            section.operation == .delete && !section.lines.contains(where: { $0.kind == .del })
+        }
+        func append(_ line: ChatToolDiffLine) {
+            if lines.count < self.maxRenderLines {
+                lines.append(line)
+            } else {
+                clipped = true
+            }
+        }
+        for section in sections {
+            // Header rows also carry move-only and header-only sections that
+            // would otherwise render nothing.
+            let isHeaderOnly = section.lines.isEmpty &&
+                (section.operation == .delete || section.path != section.sourcePath)
+            if sections.count > 1 || isHeaderOnly {
+                if !lines.isEmpty, lines.last?.kind != .skip {
+                    append(ChatToolDiffLine(kind: .skip, text: ""))
+                }
+                append(ChatToolDiffLine(kind: .file, text: self.patchSectionLabel(section)))
+            }
+            section.lines.forEach(append)
+        }
+        if clipped, lines.last?.kind != .skip {
+            lines.append(ChatToolDiffLine(kind: .skip, text: ""))
+        }
+        guard lines.contains(where: { $0.kind == .add || $0.kind == .del || $0.kind == .file }) else { return nil }
+        let stat = self.stat(for: lines)
+        // Zero/zero (move-only) and unknowable header-only-delete stats read as noise or lies.
+        let statMeaningful = !clipped && !hasHeaderOnlyDelete && (stat.added > 0 || stat.removed > 0)
+        return (lines, statMeaningful ? stat : nil)
+    }
+
+    private static func patchSectionLabel(_ section: PatchSection) -> String {
+        if section.operation == .update, section.path != section.sourcePath {
+            return "Move \(section.sourcePath) → \(section.path)"
+        }
+        let verb = switch section.operation {
+        case .add: "Add"
+        case .delete: "Delete"
+        case .update: "Update"
+        }
+        return "\(verb) \(section.path)"
+    }
+
     private static func splitLines(_ text: String) -> [String] {
         let normalized = text
             .replacingOccurrences(of: "\r\n", with: "\n")
@@ -423,7 +686,7 @@ enum ChatToolDiff {
                 ChatToolDiffStat(added: stat.added + 1, removed: stat.removed)
             case .del:
                 ChatToolDiffStat(added: stat.added, removed: stat.removed + 1)
-            case .ctx, .skip:
+            case .ctx, .file, .skip:
                 stat
             }
         }
diff --git a/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatTranscriptCache.swift b/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatTranscriptCache.swift
index d1b6cffed98e..209b6b9987fb 100644
--- a/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatTranscriptCache.swift
+++ b/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatTranscriptCache.swift
@@ -1,4 +1,5 @@
 import Foundation
+import OpenClawKit
 import OSLog
 import SQLite3
 #if os(iOS)
@@ -879,8 +880,9 @@ extension OpenClawChatSQLiteTranscriptCache {
 extension OpenClawChatSQLiteTranscriptCache {
     // MARK: - Cached shapes
 
-    /// Text rows only in v1: strip attachment/binary payloads and tool
-    /// arguments so the cache never persists base64 blobs or large payloads.
+    /// Cache v1 strips attachments and tool arguments; args-derived fallback
+    /// diffs intentionally do not survive cold paint. Only bounded applied
+    /// diff details remain so the JSON payload cannot grow without limit.
     static func cacheableMessages(_ messages: [OpenClawChatMessage]) -> [OpenClawChatMessage] {
         messages.suffix(self.maxCachedMessagesPerSession).map { message in
             OpenClawChatMessage(
@@ -898,7 +900,9 @@ extension OpenClawChatSQLiteTranscriptCache {
                         content: nil,
                         id: item.id,
                         name: item.name,
-                        arguments: nil)
+                        arguments: nil,
+                        details: self.cacheableDetails(item.details),
+                        isError: item.isError)
                 },
                 timestamp: message.timestamp,
                 idempotencyKey: message.idempotencyKey,
@@ -906,10 +910,36 @@ extension OpenClawChatSQLiteTranscriptCache {
                 toolName: message.toolName,
                 usage: message.usage,
                 stopReason: message.stopReason,
-                errorMessage: message.errorMessage)
+                errorMessage: message.errorMessage,
+                details: self.cacheableDetails(message.details),
+                isError: message.isError)
         }
     }
 
+    private static func cacheableDetails(_ details: AnyCodable?) -> AnyCodable? {
+        guard let diff = details?.dictionaryValue?["diff"]?.stringValue else { return nil }
+        let limit = 64000
+        let truncationMarker = "\n...(truncated)..."
+        let capped = if diff.utf16.count > limit {
+            self.utf16Prefix(diff, limit: limit - truncationMarker.utf16.count) + truncationMarker
+        } else {
+            diff
+        }
+        guard !capped.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty else { return nil }
+        return AnyCodable(["diff": AnyCodable(capped)])
+    }
+
+    private static func utf16Prefix(_ value: String, limit: Int) -> String {
+        let units = value.utf16
+        guard units.count > limit else { return value }
+        var end = units.index(units.startIndex, offsetBy: limit)
+        if String.Index(end, within: value) == nil {
+            end = units.index(before: end)
+        }
+        guard let stringEnd = String.Index(end, within: value) else { return "" }
+        return String(value[..<stringEnd])
+    }
+
     static func boundedSessions(_ sessions: [OpenClawChatSessionEntry]) -> [OpenClawChatSessionEntry] {
         guard sessions.count > self.maxCachedSessions else { return sessions }
         return Array(
diff --git a/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatView.swift b/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatView.swift
index ff853786af23..c4127332af99 100644
--- a/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatView.swift
+++ b/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatView.swift
@@ -961,7 +961,8 @@ extension OpenClawChatView {
                     id: toolCallId,
                     name: message.toolName,
                     arguments: nil,
-                    details: message.details))
+                    details: message.details,
+                    isError: message.isError))
 
             let merged = OpenClawChatMessage(
                 id: last.id,
@@ -976,7 +977,8 @@ extension OpenClawChatView {
                 usage: last.usage,
                 stopReason: last.stopReason,
                 errorMessage: last.errorMessage,
-                details: last.details)
+                details: last.details,
+                isError: last.isError)
             result[result.count - 1] = merged
         }
 
diff --git a/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatViewModel+HistoryReconciliation.swift b/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatViewModel+HistoryReconciliation.swift
index 6ccf5cde0a5b..76985ef3a352 100644
--- a/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatViewModel+HistoryReconciliation.swift
+++ b/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatViewModel+HistoryReconciliation.swift
@@ -29,7 +29,9 @@ extension OpenClawChatViewModel {
                 content: content.content,
                 id: content.id,
                 name: content.name,
-                arguments: content.arguments)
+                arguments: content.arguments,
+                details: content.details,
+                isError: content.isError)
         }
 
         return OpenClawChatMessage(
@@ -42,7 +44,9 @@ extension OpenClawChatViewModel {
             toolName: message.toolName,
             usage: message.usage,
             stopReason: message.stopReason,
-            errorMessage: message.errorMessage)
+            errorMessage: message.errorMessage,
+            details: message.details,
+            isError: message.isError)
     }
 
     static func messageContentFingerprint(for message: OpenClawChatMessage) -> String {
@@ -144,7 +148,8 @@ extension OpenClawChatViewModel {
             usage: incoming.usage,
             stopReason: incoming.stopReason,
             errorMessage: incoming.errorMessage,
-            details: incoming.details)
+            details: incoming.details,
+            isError: incoming.isError)
     }
 
     private static func preservingLocalAudioDurations(
@@ -175,7 +180,9 @@ extension OpenClawChatViewModel {
                 content: content.content,
                 id: content.id,
                 name: content.name,
-                arguments: content.arguments)
+                arguments: content.arguments,
+                details: content.details,
+                isError: content.isError)
         }
     }
 
@@ -445,7 +452,9 @@ extension OpenClawChatViewModel {
                 toolName: existing.toolName,
                 usage: existing.usage,
                 stopReason: existing.stopReason,
-                errorMessage: existing.errorMessage)
+                errorMessage: existing.errorMessage,
+                details: existing.details,
+                isError: existing.isError)
         }
         self.replaceMessages(Self.dedupeMessages(updated))
         guard let survivingIndex = self.messages.firstIndex(where: { message in
diff --git a/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatViewModel+TransportEvents.swift b/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatViewModel+TransportEvents.swift
index 43396aac6d53..c6e1f41eda68 100644
--- a/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatViewModel+TransportEvents.swift
+++ b/apps/shared/OpenClawKit/Sources/OpenClawChatUI/ChatViewModel+TransportEvents.swift
@@ -283,7 +283,8 @@ extension OpenClawChatViewModel {
             usage: message.usage,
             stopReason: message.stopReason,
             errorMessage: message.errorMessage,
-            details: message.details)
+            details: message.details,
+            isError: message.isError)
     }
 
     private func handleAgentEvent(_ evt: OpenClawAgentEventPayload) {
diff --git a/apps/shared/OpenClawKit/Tests/OpenClawKitTests/ChatToolActivityTests.swift b/apps/shared/OpenClawKit/Tests/OpenClawKitTests/ChatToolActivityTests.swift
index d29d9a0bea66..31cb15522d0e 100644
--- a/apps/shared/OpenClawKit/Tests/OpenClawKitTests/ChatToolActivityTests.swift
+++ b/apps/shared/OpenClawKit/Tests/OpenClawKitTests/ChatToolActivityTests.swift
@@ -15,6 +15,7 @@ struct ChatToolActivityTests {
             arguments: nil,
             details: nil,
             resultText: "done",
+            isError: false,
             isPending: false)])
     }
 
@@ -29,6 +30,7 @@ struct ChatToolActivityTests {
             arguments: nil,
             details: nil,
             resultText: "orphaned",
+            isError: false,
             isPending: false)])
     }
 
@@ -58,6 +60,7 @@ struct ChatToolActivityTests {
             arguments: nil,
             details: nil,
             resultText: nil,
+            isError: false,
             isPending: false)])
     }
 
@@ -75,12 +78,30 @@ struct ChatToolActivityTests {
         #expect(items.first?.details == details)
     }
 
+    @Test func `threads paired and orphan result errors`() {
+        let paired = ChatToolActivity.items(
+            calls: [self.content(type: "toolCall", id: "call-1", name: "edit")],
+            results: [self.content(
+                type: "toolResult",
+                text: "failed",
+                id: "call-1",
+                name: "edit",
+                isError: true)])
+        let orphan = ChatToolActivity.items(
+            calls: [],
+            results: [self.content(type: "toolResult", text: "failed", isError: true)])
+
+        #expect(paired.first?.isError == true)
+        #expect(orphan.first?.isError == true)
+    }
+
     private func content(
         type: String,
         text: String? = nil,
         id: String? = nil,
         name: String? = nil,
-        details: AnyCodable? = nil) -> OpenClawChatMessageContent
+        details: AnyCodable? = nil,
+        isError: Bool? = nil) -> OpenClawChatMessageContent
     {
         OpenClawChatMessageContent(
             type: type,
@@ -90,6 +111,7 @@ struct ChatToolActivityTests {
             content: nil,
             id: id,
             name: name,
-            details: details)
+            details: details,
+            isError: isError)
     }
 }
diff --git a/apps/shared/OpenClawKit/Tests/OpenClawKitTests/ChatToolDiffTests.swift b/apps/shared/OpenClawKit/Tests/OpenClawKitTests/ChatToolDiffTests.swift
index 13b780257a17..bea3aa586937 100644
--- a/apps/shared/OpenClawKit/Tests/OpenClawKitTests/ChatToolDiffTests.swift
+++ b/apps/shared/OpenClawKit/Tests/OpenClawKitTests/ChatToolDiffTests.swift
@@ -200,6 +200,16 @@ struct ChatToolDiffTests {
             details: AnyCodable(["diff": AnyCodable("+1 added\n-1 removed")])) == nil)
     }
 
+    @Test func `move only patches render the file header`() throws {
+        let patch = "*** Begin Patch\n*** Update File: a/old.txt\n*** Move to: a/new.txt\n*** End Patch"
+        let resolved = try #require(ChatToolDiff.resolveDiff(
+            name: "apply_patch",
+            arguments: AnyCodable(["input": AnyCodable(patch)]),
+            details: nil))
+        #expect(resolved.lines == [ChatToolDiffLine(kind: .file, text: "Move a/old.txt → a/new.txt")])
+        #expect(resolved.stat == nil)
+    }
+
     @Test func `patch tools resolve persisted details`() throws {
         let resolved = try #require(ChatToolDiff.resolveDiff(
             name: "apply_patch",
@@ -208,6 +218,127 @@ struct ChatToolDiffTests {
         #expect(resolved.stat == ChatToolDiffStat(added: 1, removed: 1))
     }
 
+    @Test func `parses numbered update patch envelopes from every argument spelling`() throws {
+        let patch = [
+            "*** Begin Patch",
+            "*** Update File: src/a.swift",
+            "@@ -4,2 +4,2 @@",
+            " context",
+            "-old",
+            "+new",
+            "*** End Patch",
+        ].joined(separator: "\n")
+
+        for key in ["patch", "input", "diff"] {
+            let resolved = try #require(ChatToolDiff.resolveDiff(
+                name: "apply_patch",
+                arguments: AnyCodable([key: AnyCodable(patch)]),
+                details: nil))
+            #expect(resolved.lines == [
+                ChatToolDiffLine(kind: .ctx, lineNo: 4, text: "context"),
+                ChatToolDiffLine(kind: .del, lineNo: 5, text: "old"),
+                ChatToolDiffLine(kind: .add, lineNo: 5, text: "new"),
+            ])
+            #expect(resolved.stat == ChatToolDiffStat(added: 1, removed: 1))
+        }
+    }
+
+    @Test func `separates add delete and move patch files`() throws {
+        let patch = [
+            "*** Begin Patch",
+            "*** Update File: src/old.swift",
+            "*** Move to: src/new.swift",
+            "@@ -1 +1 @@",
+            "-old",
+            "+new",
+            "*** Add File: src/added.swift",
+            "+added",
+            "*** Delete File: src/deleted.swift",
+            "-deleted",
+            "*** End Patch",
+        ].joined(separator: "\n")
+        let resolved = try #require(ChatToolDiff.resolveDiff(
+            name: "applypatch",
+            arguments: AnyCodable(["input": AnyCodable(patch)]),
+            details: nil))
+
+        #expect(resolved.lines == [
+            ChatToolDiffLine(kind: .file, text: "Move src/old.swift → src/new.swift"),
+            ChatToolDiffLine(kind: .del, lineNo: 1, text: "old"),
+            ChatToolDiffLine(kind: .add, lineNo: 1, text: "new"),
+            ChatToolDiffLine(kind: .skip, text: ""),
+            ChatToolDiffLine(kind: .file, text: "Add src/added.swift"),
+            ChatToolDiffLine(kind: .add, lineNo: 1, text: "added"),
+            ChatToolDiffLine(kind: .skip, text: ""),
+            ChatToolDiffLine(kind: .file, text: "Delete src/deleted.swift"),
+            ChatToolDiffLine(kind: .del, lineNo: 1, text: "deleted"),
+        ])
+        #expect(resolved.stat == ChatToolDiffStat(added: 2, removed: 2))
+    }
+
+    @Test func `rejects malformed patch envelopes`() {
+        for patch in [
+            "*** Begin Patch\nnot a file\n*** End Patch",
+            "*** Update File: \n+orphaned",
+            "*** Add File: empty.swift\n*** End Patch",
+        ] {
+            #expect(ChatToolDiff.resolveDiff(
+                name: "patch",
+                arguments: AnyCodable(["patch": AnyCodable(patch)]),
+                details: nil) == nil)
+        }
+    }
+
+    @Test func `renders header only deletes without an exact stat`() throws {
+        let deleted = try #require(ChatToolDiff.resolveDiff(
+            name: "apply_patch",
+            arguments: AnyCodable(["patch": AnyCodable("*** Delete File: obsolete.swift")]),
+            details: nil))
+        #expect(deleted.lines == [ChatToolDiffLine(kind: .file, text: "Delete obsolete.swift")])
+        #expect(deleted.stat == nil)
+
+        let multi = try #require(ChatToolDiff.resolveDiff(
+            name: "apply_patch",
+            arguments: AnyCodable(["patch": AnyCodable(
+                "*** Add File: added.swift\n+new\n*** Delete File: obsolete.swift")]),
+            details: nil))
+        #expect(multi.lines.last == ChatToolDiffLine(kind: .file, text: "Delete obsolete.swift"))
+        #expect(multi.stat == nil)
+    }
+
+    @Test func `caps patch rows and omits a partial stat`() throws {
+        let patch = (["*** Begin Patch", "*** Update File: big.swift"] +
+            (0..<450).map { "+line \($0)" } + ["*** End Patch"])
+            .joined(separator: "\n")
+        let resolved = try #require(ChatToolDiff.resolveDiff(
+            name: "apply_patch",
+            arguments: AnyCodable(["patch": AnyCodable(patch)]),
+            details: nil))
+
+        #expect(resolved.lines.count == 401)
+        #expect(resolved.lines.last == ChatToolDiffLine(kind: .skip, text: ""))
+        #expect(resolved.stat == nil)
+    }
+
+    @Test func `failed edits suppress argument proposals but keep applied details`() throws {
+        #expect(ChatToolDiff.resolveDiff(
+            name: "edit",
+            arguments: AnyCodable(["oldText": "old", "newText": "new"]),
+            details: nil,
+            isError: true) == nil)
+
+        let details = try #require(ChatToolDiff.resolveDiff(
+            name: "edit",
+            arguments: AnyCodable(["oldText": "arg old", "newText": "arg new"]),
+            details: AnyCodable(["diff": AnyCodable("-1 applied old\n+1 applied new")]),
+            isError: true))
+        #expect(details.lines == [
+            ChatToolDiffLine(kind: .del, lineNo: 1, text: "applied old"),
+            ChatToolDiffLine(kind: .add, lineNo: 1, text: "applied new"),
+        ])
+        #expect(details.stat == ChatToolDiffStat(added: 1, removed: 1))
+    }
+
     @Test func `truncated details omit the stat`() throws {
         let resolved = try #require(ChatToolDiff.resolveDiff(
             name: "edit",
@@ -239,4 +370,20 @@ struct ChatToolDiffTests {
         #expect(decoded.details == AnyCodable(["diff": AnyCodable("+1 added")]))
         #expect(roundTripped.details == decoded.details)
     }
+
+    @Test func `message and content decode snake case errors and encode canonically`() throws {
+        let data = Data(#"{"role":"toolResult","is_error":true,"content":[{"type":"tool_result","is_error":true}]}"#
+            .utf8)
+        let decoded = try JSONDecoder().decode(OpenClawChatMessage.self, from: data)
+        let encoded = try JSONEncoder().encode(decoded)
+        let object = try #require(JSONSerialization.jsonObject(with: encoded) as? [String: Any])
+        let content = try #require((object["content"] as? [[String: Any]])?.first)
+
+        #expect(decoded.isError == true)
+        #expect(decoded.content.first?.isError == true)
+        #expect(object["isError"] as? Bool == true)
+        #expect(object["is_error"] == nil)
+        #expect(content["isError"] as? Bool == true)
+        #expect(content["is_error"] == nil)
+    }
 }
diff --git a/apps/shared/OpenClawKit/Tests/OpenClawKitTests/ChatTranscriptCacheStoreTests.swift b/apps/shared/OpenClawKit/Tests/OpenClawKitTests/ChatTranscriptCacheStoreTests.swift
index 617338ab6668..845cec134704 100644
--- a/apps/shared/OpenClawKit/Tests/OpenClawKitTests/ChatTranscriptCacheStoreTests.swift
+++ b/apps/shared/OpenClawKit/Tests/OpenClawKitTests/ChatTranscriptCacheStoreTests.swift
@@ -122,6 +122,58 @@ struct ChatTranscriptCacheStoreTests {
         #expect(await store.loadTranscript(sessionKey: "unknown").isEmpty)
     }
 
+    @Test func `transcript JSON keeps only bounded diff details`() async throws {
+        let url = try makeDatabaseURL()
+        defer { try? FileManager.default.removeItem(at: url.deletingLastPathComponent()) }
+        let oversizedDiff = "+1 " + String(repeating: "x", count: 64100)
+        let message = OpenClawChatMessage(
+            role: "toolResult",
+            content: [
+                OpenClawChatMessageContent(
+                    type: "tool_result",
+                    text: "done",
+                    mimeType: nil,
+                    fileName: nil,
+                    content: nil,
+                    arguments: AnyCodable(["oldText": AnyCodable("large proposal")]),
+                    details: AnyCodable([
+                        "diff": AnyCodable("+1 block diff"),
+                        "ignored": AnyCodable("drop me"),
+                    ]),
+                    isError: true),
+                OpenClawChatMessageContent(
+                    type: "tool_result",
+                    text: "no diff",
+                    mimeType: nil,
+                    fileName: nil,
+                    content: nil,
+                    details: AnyCodable(["ignored": AnyCodable("drop me")])),
+            ],
+            timestamp: 1,
+            details: AnyCodable([
+                "diff": AnyCodable(oversizedDiff),
+                "ignored": AnyCodable("drop me"),
+            ]),
+            isError: true)
+
+        let cacheable = try #require(OpenClawChatSQLiteTranscriptCache.cacheableMessages([message]).first)
+        #expect(cacheable.content.allSatisfy { $0.arguments == nil })
+        #expect(Set(cacheable.details?.dictionaryValue?.keys.map(\.self) ?? []) == ["diff"])
+        #expect(cacheable.details?.dictionaryValue?["diff"]?.stringValue?.utf16.count == 64000)
+        #expect(cacheable.details?.dictionaryValue?["diff"]?.stringValue?.hasSuffix("\n...(truncated)...") == true)
+        #expect(Set(cacheable.content[0].details?.dictionaryValue?.keys.map(\.self) ?? []) == ["diff"])
+        #expect(cacheable.content[1].details == nil)
+        #expect(cacheable.isError == true)
+        #expect(cacheable.content[0].isError == true)
+
+        let store = OpenClawChatSQLiteTranscriptCache(databaseURL: url, gatewayID: "gw-a")
+        await store.storeTranscript(sessionKey: "main", messages: [message])
+        let decoded = try #require(await store.loadTranscript(sessionKey: "main").first)
+        #expect(decoded.details == cacheable.details)
+        #expect(decoded.content[0].details == cacheable.content[0].details)
+        #expect(ChatToolDiff.resolveDiff(name: "edit", arguments: nil, details: decoded.details)?.stat == nil)
+    }
+
     @Test func `transcript keeps only most recent messages within bound`() async throws {
         let url = try makeDatabaseURL()
         defer { try? FileManager.default.removeItem(at: url.deletingLastPathComponent()) }