diff --git a/src/features/chat/application/pending-requests/state.ts b/src/features/chat/application/pending-requests/state.ts
index 39b7f752..6c6c1bf6 100644
--- a/src/features/chat/application/pending-requests/state.ts
+++ b/src/features/chat/application/pending-requests/state.ts
@@ -7,6 +7,7 @@ import {
   type PendingRequestId,
   type PendingUserInput,
 } from "../../../../domain/pending-requests/model";
+import { patchObject } from "../state/patch";
 
 export interface ChatRequestState {
   readonly approvals: readonly PendingApproval[];
@@ -107,8 +108,3 @@ function setMcpElicitationDraftSlice(state: ChatRequestState, key: string, value
   if (state.mcpElicitationDrafts.get(key) === value) return state;
   return patchObject(state, { mcpElicitationDrafts: new Map([...state.mcpElicitationDrafts, [key, value]]) });
 }
-
-function patchObject<T extends object>(current: T, patch: Partial<T>): T {
-  if (Object.entries(patch).every(([key, value]) => Object.is(current[key as keyof T], value))) return current;
-  return { ...current, ...patch };
-}
diff --git a/src/features/chat/application/state/clone.ts b/src/features/chat/application/state/clone.ts
new file mode 100644
index 00000000..290d5e3e
--- /dev/null
+++ b/src/features/chat/application/state/clone.ts
@@ -0,0 +1,61 @@
+import type { ChatState } from "./root-reducer";
+import { cloneDisclosureUiState } from "./ui-state";
+import type { ChatMessageStreamActiveSegment, ChatMessageStreamState } from "./message-stream";
+
+export function cloneChatState(state: ChatState): ChatState {
+  return {
+    connection: {
+      ...state.connection,
+      availableModels: [...state.connection.availableModels],
+      availableSkills: [...state.connection.availableSkills],
+    },
+    threadList: {
+      listedThreads: [...state.threadList.listedThreads],
+      threadsLoaded: state.threadList.threadsLoaded,
+    },
+    activeThread: { ...state.activeThread },
+    runtime: { ...state.runtime },
+    turn: { lifecycle: state.turn.lifecycle },
+    messageStream: cloneMessageStreamState(state.messageStream),
+    requests: {
+      approvals: [...state.requests.approvals],
+      pendingUserInputs: [...state.requests.pendingUserInputs],
+      pendingMcpElicitations: [...state.requests.pendingMcpElicitations],
+      userInputDrafts: new Map(state.requests.userInputDrafts),
+      mcpElicitationDrafts: new Map(state.requests.mcpElicitationDrafts),
+    },
+    composer: {
+      ...state.composer,
+      suggestions: [...state.composer.suggestions],
+    },
+    ui: {
+      toolbarPanel: state.ui.toolbarPanel,
+      archiveConfirmThreadId: state.ui.archiveConfirmThreadId,
+      rename: { ...state.ui.rename },
+      goalEditor: { ...state.ui.goalEditor },
+      messageActionMenu: { ...state.ui.messageActionMenu },
+      disclosures: cloneDisclosureUiState(state.ui.disclosures),
+    },
+  };
+}
+
+function cloneMessageStreamState(state: ChatMessageStreamState): ChatMessageStreamState {
+  return {
+    stableItems: [...state.stableItems],
+    activeSegment: cloneActiveSegment(state.activeSegment),
+    turnDiffs: new Map(state.turnDiffs),
+    historyCursor: state.historyCursor,
+    loadingHistory: state.loadingHistory,
+    reportedLogs: new Set(state.reportedLogs),
+  };
+}
+
+function cloneActiveSegment(segment: ChatMessageStreamActiveSegment | null): ChatMessageStreamActiveSegment | null {
+  if (!segment) return null;
+  return {
+    turnId: segment.turnId,
+    items: [...segment.items],
+    indexById: new Map(segment.indexById),
+    indexBySourceItemId: new Map(segment.indexBySourceItemId),
+  };
+}
diff --git a/src/features/chat/application/state/message-stream.ts b/src/features/chat/application/state/message-stream.ts
index 0d4908b2..c580e37c 100644
--- a/src/features/chat/application/state/message-stream.ts
+++ b/src/features/chat/application/state/message-stream.ts
@@ -8,6 +8,7 @@ import {
   streamedTextMessageStreamItem,
   streamedToolOutputMessageStreamItem,
 } from "../../domain/message-stream/factories/streaming-items";
+import { definedPatch, patchObject } from "./patch";
 
 export interface ChatMessageStreamActiveSegment {
   readonly turnId: string | null;
@@ -545,12 +546,3 @@ function promptMessageForTurn(items: readonly MessageStreamItem[], turnId: strin
   const item = classification?.item;
   return item?.kind === "message" ? item : null;
 }
-
-function patchObject<T extends object>(current: T, patch: Partial<T>): T {
-  if (Object.entries(patch).every(([key, value]) => Object.is(current[key as keyof T], value))) return current;
-  return { ...current, ...patch };
-}
-
-function definedPatch<Key extends string, Value>(key: Key, value: Value | undefined): Partial<Record<Key, Value>> {
-  return value === undefined ? {} : ({ [key]: value } as Partial<Record<Key, Value>>);
-}
diff --git a/src/features/chat/application/state/patch.ts b/src/features/chat/application/state/patch.ts
new file mode 100644
index 00000000..3a120f96
--- /dev/null
+++ b/src/features/chat/application/state/patch.ts
@@ -0,0 +1,8 @@
+export function patchObject<T extends object>(current: T, patch: Partial<T>): T {
+  if (Object.entries(patch).every(([key, value]) => Object.is(current[key as keyof T], value))) return current;
+  return { ...current, ...patch };
+}
+
+export function definedPatch<Key extends string, Value>(key: Key, value: Value | undefined): Partial<Record<Key, Value>> {
+  return value === undefined ? {} : ({ [key]: value } as Partial<Record<Key, Value>>);
+}
diff --git a/src/features/chat/application/state/root-reducer.ts b/src/features/chat/application/state/root-reducer.ts
index c9de9039..fe824547 100644
--- a/src/features/chat/application/state/root-reducer.ts
+++ b/src/features/chat/application/state/root-reducer.ts
@@ -49,7 +49,6 @@ import {
   messageStreamWithActiveTurnItems,
   messageStreamWithItems,
   reduceMessageStreamSlice,
-  type ChatMessageStreamActiveSegment,
   type ChatMessageStreamState,
   type MessageStreamAction,
 } from "./message-stream";
@@ -70,7 +69,6 @@ import {
 import {
   clearAllRequestDisclosures,
   clearResolvedRequestDisclosures,
-  cloneDisclosureUiState,
   initialUiState,
   isUiAction,
   maybeClearGoalObjectiveExpansion,
@@ -79,6 +77,7 @@ import {
   type UiAction,
 } from "./ui-state";
 import { STATUS_TURN_RUNNING } from "./status-text";
+import { definedPatch, patchObject } from "./patch";
 
 export { activeTurnId, chatTurnBusy, pendingTurnStart, type ChatTurnState, type PendingTurnStart } from "../conversation/turn-state";
 export type { ChatMessageStreamState } from "./message-stream";
@@ -658,64 +657,6 @@ function initialComposerState(): ChatComposerState {
   };
 }
 
-export function cloneChatState(state: ChatState): ChatState {
-  return {
-    connection: {
-      ...state.connection,
-      availableModels: [...state.connection.availableModels],
-      availableSkills: [...state.connection.availableSkills],
-    },
-    threadList: {
-      listedThreads: [...state.threadList.listedThreads],
-      threadsLoaded: state.threadList.threadsLoaded,
-    },
-    activeThread: { ...state.activeThread },
-    runtime: { ...state.runtime },
-    turn: { lifecycle: state.turn.lifecycle },
-    messageStream: cloneMessageStreamState(state.messageStream),
-    requests: {
-      approvals: [...state.requests.approvals],
-      pendingUserInputs: [...state.requests.pendingUserInputs],
-      pendingMcpElicitations: [...state.requests.pendingMcpElicitations],
-      userInputDrafts: new Map(state.requests.userInputDrafts),
-      mcpElicitationDrafts: new Map(state.requests.mcpElicitationDrafts),
-    },
-    composer: {
-      ...state.composer,
-      suggestions: [...state.composer.suggestions],
-    },
-    ui: {
-      toolbarPanel: state.ui.toolbarPanel,
-      archiveConfirmThreadId: state.ui.archiveConfirmThreadId,
-      rename: { ...state.ui.rename },
-      goalEditor: { ...state.ui.goalEditor },
-      messageActionMenu: { ...state.ui.messageActionMenu },
-      disclosures: cloneDisclosureUiState(state.ui.disclosures),
-    },
-  };
-}
-
-function cloneMessageStreamState(state: ChatMessageStreamState): ChatMessageStreamState {
-  return {
-    stableItems: [...state.stableItems],
-    activeSegment: cloneActiveSegment(state.activeSegment),
-    turnDiffs: new Map(state.turnDiffs),
-    historyCursor: state.historyCursor,
-    loadingHistory: state.loadingHistory,
-    reportedLogs: new Set(state.reportedLogs),
-  };
-}
-
-function cloneActiveSegment(segment: ChatMessageStreamActiveSegment | null): ChatMessageStreamActiveSegment | null {
-  if (!segment) return null;
-  return {
-    turnId: segment.turnId,
-    items: [...segment.items],
-    indexById: new Map(segment.indexById),
-    indexBySourceItemId: new Map(segment.indexBySourceItemId),
-  };
-}
-
 function setComposerSuggestionsSlice(
   state: ChatComposerState,
   suggestions: readonly ComposerSuggestion[],
@@ -751,16 +692,6 @@ function composerSuggestionsEqual(left: readonly ComposerSuggestion[], right: re
   });
 }
 
-function patchObject<T extends object>(current: T, patch: Partial<T>): T {
-  if (Object.entries(patch).every(([key, value]) => Object.is(current[key as keyof T], value))) return current;
-  return { ...current, ...patch };
-}
-
 function patchChatState(state: ChatState, patch: Partial<ChatState>): ChatState {
-  if (Object.entries(patch).every(([key, value]) => Object.is(state[key as keyof ChatState], value))) return state;
-  return { ...state, ...patch };
-}
-
-function definedPatch<Key extends string, Value>(key: Key, value: Value | undefined): Partial<Record<Key, Value>> {
-  return value === undefined ? {} : ({ [key]: value } as Partial<Record<Key, Value>>);
+  return patchObject(state, patch);
 }
diff --git a/src/features/chat/application/state/store.ts b/src/features/chat/application/state/store.ts
index a370d252..8d32bcd3 100644
--- a/src/features/chat/application/state/store.ts
+++ b/src/features/chat/application/state/store.ts
@@ -1,4 +1,5 @@
-import { chatReducer, cloneChatState, createChatState, type ChatAction, type ChatState } from "./root-reducer";
+import { cloneChatState } from "./clone";
+import { chatReducer, createChatState, type ChatAction, type ChatState } from "./root-reducer";
 
 export interface ChatStateStore {
   getState(): ChatState;
diff --git a/src/features/chat/application/state/ui-state.ts b/src/features/chat/application/state/ui-state.ts
index da56516f..144a3448 100644
--- a/src/features/chat/application/state/ui-state.ts
+++ b/src/features/chat/application/state/ui-state.ts
@@ -9,6 +9,7 @@ import {
   type ThreadRenameLifecycleState,
 } from "../../../threads/rename-lifecycle";
 import type { DisclosureSetAction } from "./actions";
+import { patchObject } from "./patch";
 
 export type ChatRenameUiState = { readonly kind: "idle" } | (ThreadRenameActiveState & { readonly threadId: string });
 
@@ -397,8 +398,3 @@ function filterStringSet(values: ReadonlySet<string>, keep: (value: string) => b
   }
   return next ?? values;
 }
-
-function patchObject<T extends object>(current: T, patch: Partial<T>): T {
-  if (Object.entries(patch).every(([key, value]) => Object.is(current[key as keyof T], value))) return current;
-  return { ...current, ...patch };
-}