diff --git a/packages/vscode-ide-companion/src/diff-manager.ts b/packages/vscode-ide-companion/src/diff-manager.ts
index 8367517abd6..755143a4e44 100644
--- a/packages/vscode-ide-companion/src/diff-manager.ts
+++ b/packages/vscode-ide-companion/src/diff-manager.ts
@@ -14,7 +14,7 @@ import * as vscode from 'vscode';
 import { DIFF_SCHEME } from './extension.js';
 import {
   findLeftGroupOfChatWebview,
-  ensureLeftGroupOfChatWebview,
+  findRightGroupOfChatWebview,
 } from './utils/editorGroupUtils.js';
 
 export class DiffContentProvider implements vscode.TextDocumentContentProvider {
@@ -222,17 +222,14 @@ export class DiffManager {
       true,
     );
 
-    // Prefer opening the diff adjacent to the chat webview (so we don't
-    // replace content inside the locked webview group). We try the group to
-    // the left of the chat webview first; if none exists we fall back to
-    // ViewColumn.Beside. With the chat locked in the leftmost group, this
-    // fallback opens diffs to the right of the chat.
-    let targetViewColumn = findLeftGroupOfChatWebview();
-    if (targetViewColumn === undefined) {
-      // If there is no left neighbor, create one to satisfy the requirement of
-      // opening diffs to the left of the chat webview.
-      targetViewColumn = await ensureLeftGroupOfChatWebview();
-    }
+    // Prefer opening the diff in the group to the left of the chat webview.
+    // When that isn't available (e.g. chat is in the leftmost group), try the
+    // group to the right so we reuse existing layout. Only fall back to
+    // ViewColumn.Beside when neither neighbor exists or the webview is missing.
+    const targetViewColumn =
+      findLeftGroupOfChatWebview() ??
+      findRightGroupOfChatWebview() ??
+      vscode.ViewColumn.Beside;
 
     await vscode.commands.executeCommand(
       'vscode.diff',
@@ -240,10 +237,7 @@ export class DiffManager {
       rightDocUri,
       diffTitle,
       {
-        // If a left-of-webview group was found, target it explicitly so the
-        // diff opens there while keeping focus on the webview. Otherwise, use
-        // the default "open to side" behavior.
-        viewColumn: targetViewColumn ?? vscode.ViewColumn.Beside,
+        viewColumn: targetViewColumn,
         preview: false,
         preserveFocus: true,
       },
diff --git a/packages/vscode-ide-companion/src/utils/editorGroupUtils.test.ts b/packages/vscode-ide-companion/src/utils/editorGroupUtils.test.ts
new file mode 100644
index 00000000000..a8dd4ce38f5
--- /dev/null
+++ b/packages/vscode-ide-companion/src/utils/editorGroupUtils.test.ts
@@ -0,0 +1,175 @@
+/**
+ * @license
+ * Copyright 2025 Qwen Team
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+
+const chatViewType = 'mainThreadWebview-qwenCode.chat';
+
+const vscodeMock = vi.hoisted(() => ({
+  ViewColumn: { One: 1, Two: 2, Three: 3, Four: 4 },
+  window: {
+    tabGroups: {
+      all: [] as Array<{ tabs: Array<{ input: unknown }>; viewColumn: number }>,
+    },
+  },
+}));
+
+vi.mock('vscode', () => vscodeMock);
+
+import {
+  findLeftGroupOfChatWebview,
+  findRightGroupOfChatWebview,
+} from './editorGroupUtils.js';
+
+function chatTab() {
+  return { input: { viewType: chatViewType } };
+}
+
+function regularTab() {
+  return { input: { viewType: 'default' } };
+}
+
+describe('findLeftGroupOfChatWebview', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    vscodeMock.window.tabGroups.all = [];
+  });
+
+  it('returns the nearest left neighbor when chat webview has a group to its left', () => {
+    vscodeMock.window.tabGroups.all = [
+      { tabs: [regularTab()], viewColumn: 1 },
+      { tabs: [chatTab()], viewColumn: 2 },
+      { tabs: [regularTab()], viewColumn: 3 },
+    ];
+
+    expect(findLeftGroupOfChatWebview()).toBe(1);
+  });
+
+  it('returns the closest left neighbor when multiple left groups exist', () => {
+    vscodeMock.window.tabGroups.all = [
+      { tabs: [regularTab()], viewColumn: 1 },
+      { tabs: [regularTab()], viewColumn: 2 },
+      { tabs: [chatTab()], viewColumn: 4 },
+      { tabs: [regularTab()], viewColumn: 5 },
+    ];
+
+    // closest left is group 2, not group 1
+    expect(findLeftGroupOfChatWebview()).toBe(2);
+  });
+
+  it('returns undefined when chat webview is in the leftmost group', () => {
+    vscodeMock.window.tabGroups.all = [
+      { tabs: [chatTab()], viewColumn: 1 },
+      { tabs: [regularTab()], viewColumn: 2 },
+    ];
+
+    expect(findLeftGroupOfChatWebview()).toBeUndefined();
+  });
+
+  it('returns undefined when no chat webview is found', () => {
+    vscodeMock.window.tabGroups.all = [
+      { tabs: [regularTab()], viewColumn: 1 },
+      { tabs: [regularTab()], viewColumn: 2 },
+    ];
+
+    expect(findLeftGroupOfChatWebview()).toBeUndefined();
+  });
+
+  it('returns undefined when there are no tab groups', () => {
+    vscodeMock.window.tabGroups.all = [];
+
+    expect(findLeftGroupOfChatWebview()).toBeUndefined();
+  });
+
+  it('returns undefined when tabGroups access throws', () => {
+    // make .all throw on access
+    Object.defineProperty(vscodeMock.window.tabGroups, 'all', {
+      get: () => {
+        throw new Error('unexpected error');
+      },
+      configurable: true,
+    });
+
+    expect(findLeftGroupOfChatWebview()).toBeUndefined();
+
+    // restore
+    Object.defineProperty(vscodeMock.window.tabGroups, 'all', {
+      value: [],
+      configurable: true,
+      writable: true,
+    });
+  });
+});
+
+describe('findRightGroupOfChatWebview', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    vscodeMock.window.tabGroups.all = [];
+  });
+
+  it('returns the nearest right neighbor when chat webview has a group to its right', () => {
+    vscodeMock.window.tabGroups.all = [
+      { tabs: [regularTab()], viewColumn: 1 },
+      { tabs: [chatTab()], viewColumn: 2 },
+      { tabs: [regularTab()], viewColumn: 3 },
+    ];
+
+    expect(findRightGroupOfChatWebview()).toBe(3);
+  });
+
+  it('returns the closest right neighbor when multiple right groups exist', () => {
+    vscodeMock.window.tabGroups.all = [
+      { tabs: [regularTab()], viewColumn: 1 },
+      { tabs: [chatTab()], viewColumn: 2 },
+      { tabs: [regularTab()], viewColumn: 3 },
+      { tabs: [regularTab()], viewColumn: 5 },
+    ];
+
+    // closest right is group 3, not group 5
+    expect(findRightGroupOfChatWebview()).toBe(3);
+  });
+
+  it('returns undefined when chat webview is in the rightmost group', () => {
+    vscodeMock.window.tabGroups.all = [
+      { tabs: [regularTab()], viewColumn: 1 },
+      { tabs: [chatTab()], viewColumn: 3 },
+    ];
+
+    expect(findRightGroupOfChatWebview()).toBeUndefined();
+  });
+
+  it('returns undefined when no chat webview is found', () => {
+    vscodeMock.window.tabGroups.all = [
+      { tabs: [regularTab()], viewColumn: 1 },
+      { tabs: [regularTab()], viewColumn: 2 },
+    ];
+
+    expect(findRightGroupOfChatWebview()).toBeUndefined();
+  });
+
+  it('returns undefined when there are no tab groups', () => {
+    vscodeMock.window.tabGroups.all = [];
+
+    expect(findRightGroupOfChatWebview()).toBeUndefined();
+  });
+
+  it('returns undefined when tabGroups access throws', () => {
+    Object.defineProperty(vscodeMock.window.tabGroups, 'all', {
+      get: () => {
+        throw new Error('unexpected error');
+      },
+      configurable: true,
+    });
+
+    expect(findRightGroupOfChatWebview()).toBeUndefined();
+
+    Object.defineProperty(vscodeMock.window.tabGroups, 'all', {
+      value: [],
+      configurable: true,
+      writable: true,
+    });
+  });
+});
diff --git a/packages/vscode-ide-companion/src/utils/editorGroupUtils.ts b/packages/vscode-ide-companion/src/utils/editorGroupUtils.ts
index e855b2dec04..3326cd33683 100644
--- a/packages/vscode-ide-companion/src/utils/editorGroupUtils.ts
+++ b/packages/vscode-ide-companion/src/utils/editorGroupUtils.ts
@@ -5,159 +5,78 @@
  */
 
 import * as vscode from 'vscode';
-import { openChatCommand } from '../commands/index.js';
+
+const CHAT_WEBVIEW_TYPE = 'mainThreadWebview-qwenCode.chat';
+
+function isChatWebview(tab: vscode.Tab): boolean {
+  const input: unknown = (tab as { input?: unknown }).input;
+  return (
+    !!input &&
+    typeof input === 'object' &&
+    (input as { viewType: string }).viewType === CHAT_WEBVIEW_TYPE
+  );
+}
+
+function findWebviewGroup(): vscode.TabGroup | undefined {
+  return vscode.window.tabGroups.all.find((group) =>
+    group.tabs.some(isChatWebview),
+  );
+}
+
+function findNeighborGroup(
+  isOnSide: (v: vscode.ViewColumn) => boolean,
+  isCloser: (cur: vscode.ViewColumn, cand: vscode.ViewColumn) => boolean,
+): vscode.ViewColumn | undefined {
+  let candidate: vscode.ViewColumn | undefined;
+  for (const g of vscode.window.tabGroups.all) {
+    if (!isOnSide(g.viewColumn)) continue;
+    if (candidate === undefined || isCloser(candidate, g.viewColumn)) {
+      candidate = g.viewColumn;
+    }
+  }
+  return candidate;
+}
 
 /**
  * Find the editor group immediately to the left of the Qwen chat webview.
  * - If the chat webview group is the leftmost group, returns undefined.
  * - If no chat webview is found in any editor group, returns undefined.
- * - Uses the webview tab viewType 'mainThreadWebview-qwenCode.chat'.
  */
 export function findLeftGroupOfChatWebview(): vscode.ViewColumn | undefined {
   try {
-    const groups = vscode.window.tabGroups.all;
-
-    // Locate the group that contains our chat webview
-    const webviewGroup = groups.find((group) =>
-      group.tabs.some((tab) => {
-        const input: unknown = (tab as { input?: unknown }).input;
-        const isWebviewInput = (inp: unknown): inp is { viewType: string } =>
-          !!inp && typeof inp === 'object' && 'viewType' in inp;
-        return (
-          isWebviewInput(input) &&
-          input.viewType === 'mainThreadWebview-qwenCode.chat'
-        );
-      }),
-    );
-
+    const webviewGroup = findWebviewGroup();
     if (!webviewGroup) {
       return undefined;
     }
 
-    // Among all groups to the left (smaller viewColumn), choose the one with
-    // the largest viewColumn value (i.e. the immediate neighbor on the left).
-    let candidate:
-      | { group: vscode.TabGroup; viewColumn: vscode.ViewColumn }
-      | undefined;
-    for (const g of groups) {
-      if (g.viewColumn < webviewGroup.viewColumn) {
-        if (!candidate || g.viewColumn > candidate.viewColumn) {
-          candidate = { group: g, viewColumn: g.viewColumn };
-        }
-      }
-    }
-
-    return candidate?.viewColumn;
+    // Among groups with smaller viewColumn, pick the largest (closest neighbor).
+    return findNeighborGroup(
+      (v) => v < webviewGroup.viewColumn,
+      (cur, cand) => cand > cur,
+    );
   } catch (_err) {
-    // Best-effort only; fall back to default behavior if anything goes wrong
     return undefined;
   }
 }
 
 /**
- * Wait for a condition to become true, driven by tab-group change events.
- * Falls back to a timeout to avoid hanging forever.
- */
-function waitForTabGroupsCondition(
-  condition: () => boolean,
-  timeout: number = 2000,
-): Promise<boolean> {
-  if (condition()) {
-    return Promise.resolve(true);
-  }
-
-  return new Promise<boolean>((resolve) => {
-    const subscription = vscode.window.tabGroups.onDidChangeTabGroups(() => {
-      if (!condition()) {
-        return;
-      }
-      clearTimeout(timeoutHandle);
-      subscription.dispose();
-      resolve(true);
-    });
-
-    const timeoutHandle = setTimeout(() => {
-      subscription.dispose();
-      resolve(false);
-    }, timeout);
-  });
-}
-
-/**
- * Ensure there is an editor group directly to the left of the Qwen chat webview.
- * - If one exists, return its ViewColumn.
- * - If none exists, focus the chat panel and create a new group on its left,
- *   then return the new group's ViewColumn.
- * - If the chat webview cannot be located, returns undefined.
+ * Find the editor group immediately to the right of the Qwen chat webview.
+ * - If the chat webview group is the rightmost group, returns undefined.
+ * - If no chat webview is found in any editor group, returns undefined.
  */
-export async function ensureLeftGroupOfChatWebview(): Promise<
-  vscode.ViewColumn | undefined
-> {
-  // First try to find an existing left neighbor
-  const existing = findLeftGroupOfChatWebview();
-  if (existing !== undefined) {
-    return existing;
-  }
-
-  // Locate the chat webview group
-  const groups = vscode.window.tabGroups.all;
-  const webviewGroup = groups.find((group) =>
-    group.tabs.some((tab) => {
-      const input: unknown = (tab as { input?: unknown }).input;
-      const isWebviewInput = (inp: unknown): inp is { viewType: string } =>
-        !!inp && typeof inp === 'object' && 'viewType' in inp;
-      return (
-        isWebviewInput(input) &&
-        input.viewType === 'mainThreadWebview-qwenCode.chat'
-      );
-    }),
-  );
-
-  if (!webviewGroup) {
-    return undefined;
-  }
-
-  const initialGroupCount = vscode.window.tabGroups.all.length;
-
-  // Make the chat group active by revealing the panel
+export function findRightGroupOfChatWebview(): vscode.ViewColumn | undefined {
   try {
-    await vscode.commands.executeCommand(openChatCommand);
-  } catch {
-    // Best-effort; continue even if this fails
-  }
+    const webviewGroup = findWebviewGroup();
+    if (!webviewGroup) {
+      return undefined;
+    }
 
-  // Create a new group to the left of the chat group
-  try {
-    await vscode.commands.executeCommand('workbench.action.newGroupLeft');
-  } catch {
-    // If we fail to create a group, fall back to default behavior
+    // Among groups with larger viewColumn, pick the smallest (closest neighbor).
+    return findNeighborGroup(
+      (v) => v > webviewGroup.viewColumn,
+      (cur, cand) => cand < cur,
+    );
+  } catch (_err) {
     return undefined;
   }
-
-  // Wait for the new group to actually be created (check that group count increased)
-  const groupCreated = await waitForTabGroupsCondition(
-    () => vscode.window.tabGroups.all.length > initialGroupCount,
-    1000, // 1 second timeout
-  );
-
-  if (!groupCreated) {
-    // Fallback if group creation didn't complete in time
-    return vscode.ViewColumn.One;
-  }
-
-  // After creating a new group to the left, the new group takes ViewColumn.One
-  // and all existing groups shift right. So the new left group is always ViewColumn.One.
-  // However, to be safe, let's query for it again.
-  const newLeftGroup = findLeftGroupOfChatWebview();
-
-  // Restore focus to chat (optional), so we don't disturb user focus
-  try {
-    await vscode.commands.executeCommand(openChatCommand);
-  } catch {
-    // Ignore
-  }
-
-  // If we successfully found the new left group, return it
-  // Otherwise, fallback to ViewColumn.One (the newly created group should be first)
-  return newLeftGroup ?? vscode.ViewColumn.One;
 }
diff --git a/packages/vscode-ide-companion/src/webview/handlers/FileMessageHandler.test.ts b/packages/vscode-ide-companion/src/webview/handlers/FileMessageHandler.test.ts
index d6ff4c4a9f5..faeaa8f19f7 100644
--- a/packages/vscode-ide-companion/src/webview/handlers/FileMessageHandler.test.ts
+++ b/packages/vscode-ide-companion/src/webview/handlers/FileMessageHandler.test.ts
@@ -32,10 +32,12 @@ const vscodeMock = vi.hoisted(() => {
 
   return {
     Uri,
+    ViewColumn: { One: 1, Two: 2, Three: 3, Beside: -2 },
     workspace: {
       findFiles: vi.fn(),
       getWorkspaceFolder: vi.fn(),
       asRelativePath: vi.fn(),
+      openTextDocument: vi.fn(),
       workspaceFolders: [] as vscode.WorkspaceFolder[],
       createFileSystemWatcher: vi.fn(() => ({
         onDidCreate: vi.fn(),
@@ -47,8 +49,12 @@ const vscodeMock = vi.hoisted(() => {
     },
     window: {
       activeTextEditor: undefined,
+      showTextDocument: vi.fn(),
       tabGroups: {
-        all: [],
+        all: [] as Array<{
+          tabs: Array<{ input: unknown }>;
+          viewColumn: number;
+        }>,
       },
     },
   };
@@ -74,6 +80,15 @@ vi.mock('@qwen-code/qwen-code-core/src/utils/filesearch/crawlCache.js', () => ({
   clear: vi.fn(),
 }));
 
+const readonlyProviderMock = vi.hoisted(() => ({
+  createUri: vi.fn(),
+  setContent: vi.fn(),
+  getInstance: vi.fn(),
+}));
+vi.mock('../../services/readonlyFileSystemProvider.js', () => ({
+  ReadonlyFileSystemProvider: readonlyProviderMock,
+}));
+
 describe('FileMessageHandler', () => {
   beforeEach(() => {
     vi.clearAllMocks();
@@ -183,4 +198,106 @@ describe('FileMessageHandler', () => {
     expect(payload.type).toBe('workspaceFiles');
     expect(payload.data.requestId).toBe(7);
   });
+
+  describe('createAndOpenTempFile viewColumn selection', () => {
+    const chatViewType = 'mainThreadWebview-qwenCode.chat';
+
+    beforeEach(() => {
+      vi.clearAllMocks();
+      readonlyProviderMock.getInstance.mockReturnValue(readonlyProviderMock);
+      readonlyProviderMock.createUri.mockReturnValue(
+        vscodeMock.Uri.file('/tmp/temp.txt'),
+      );
+      readonlyProviderMock.setContent.mockReturnValue(undefined);
+      vscodeMock.workspace.openTextDocument.mockResolvedValue({
+        uri: vscodeMock.Uri.file('/tmp/temp.txt'),
+      });
+      vscodeMock.window.showTextDocument.mockResolvedValue(undefined);
+      // ensure the existing-tab search finds nothing
+      vscodeMock.window.tabGroups.all = [];
+    });
+
+    function chatTab() {
+      return { input: { viewType: chatViewType as unknown } };
+    }
+
+    function regularTab() {
+      return { input: { viewType: 'default' as unknown } };
+    }
+
+    it('opens in left group when chat webview has a left neighbor', async () => {
+      vscodeMock.window.tabGroups.all = [
+        { tabs: [regularTab()], viewColumn: 1 },
+        { tabs: [chatTab()], viewColumn: 2 },
+      ];
+
+      const sendToWebView = vi.fn();
+      const handler = new FileMessageHandler(
+        {} as QwenAgentManager,
+        {} as ConversationStore,
+        null,
+        sendToWebView,
+      );
+
+      await handler.handle({
+        type: 'createAndOpenTempFile' as never,
+        data: { content: 'hello', fileName: 'test.txt' },
+      });
+
+      expect(vscodeMock.window.showTextDocument).toHaveBeenCalledTimes(1);
+      const options = vscodeMock.window.showTextDocument.mock.calls[0]?.[1] as {
+        viewColumn: number;
+      };
+      expect(options.viewColumn).toBe(1);
+    });
+
+    it('opens in right group when no left neighbor but right exists', async () => {
+      vscodeMock.window.tabGroups.all = [
+        { tabs: [chatTab()], viewColumn: 1 },
+        { tabs: [regularTab()], viewColumn: 2 },
+      ];
+
+      const sendToWebView = vi.fn();
+      const handler = new FileMessageHandler(
+        {} as QwenAgentManager,
+        {} as ConversationStore,
+        null,
+        sendToWebView,
+      );
+
+      await handler.handle({
+        type: 'createAndOpenTempFile' as never,
+        data: { content: 'hello', fileName: 'test.txt' },
+      });
+
+      expect(vscodeMock.window.showTextDocument).toHaveBeenCalledTimes(1);
+      const options = vscodeMock.window.showTextDocument.mock.calls[0]?.[1] as {
+        viewColumn: number;
+      };
+      expect(options.viewColumn).toBe(2);
+    });
+
+    it('falls back to ViewColumn.Beside when neither left nor right neighbor exists', async () => {
+      vscodeMock.window.tabGroups.all = [{ tabs: [chatTab()], viewColumn: 1 }];
+
+      const sendToWebView = vi.fn();
+      const handler = new FileMessageHandler(
+        {} as QwenAgentManager,
+        {} as ConversationStore,
+        null,
+        sendToWebView,
+      );
+
+      await handler.handle({
+        type: 'createAndOpenTempFile' as never,
+        data: { content: 'hello', fileName: 'test.txt' },
+      });
+
+      expect(vscodeMock.window.showTextDocument).toHaveBeenCalledTimes(1);
+      const options = vscodeMock.window.showTextDocument.mock.calls[0]?.[1] as {
+        viewColumn: number;
+      };
+      expect(options.viewColumn).toBe(vscodeMock.ViewColumn.Beside);
+    });
+  });
 });
diff --git a/packages/vscode-ide-companion/src/webview/handlers/FileMessageHandler.ts b/packages/vscode-ide-companion/src/webview/handlers/FileMessageHandler.ts
index f8708d8d4d3..547cd6108a6 100644
--- a/packages/vscode-ide-companion/src/webview/handlers/FileMessageHandler.ts
+++ b/packages/vscode-ide-companion/src/webview/handlers/FileMessageHandler.ts
@@ -10,7 +10,7 @@ import { getFileName } from '../utils/webviewUtils.js';
 import { showDiffCommand } from '../../commands/index.js';
 import {
   findLeftGroupOfChatWebview,
-  ensureLeftGroupOfChatWebview,
+  findRightGroupOfChatWebview,
 } from '../../utils/editorGroupUtils.js';
 import { ReadonlyFileSystemProvider } from '../../services/readonlyFileSystemProvider.js';
 import { FileDiscoveryService } from '@qwen-code/qwen-code-core/src/services/fileDiscoveryService.js';
@@ -673,16 +673,17 @@ export class FileMessageHandler extends BaseMessageHandler {
         return;
       }
 
-      // Find or ensure left group of chat webview
-      let targetViewColumn = findLeftGroupOfChatWebview();
-      if (targetViewColumn === undefined) {
-        targetViewColumn = await ensureLeftGroupOfChatWebview();
-      }
+      // Find the nearest editor group to the left or right of the chat webview.
+      // Fall back to ViewColumn.Beside when neither neighbor exists or the webview is missing.
+      const targetViewColumn =
+        findLeftGroupOfChatWebview() ??
+        findRightGroupOfChatWebview() ??
+        vscode.ViewColumn.Beside;
 
-      // Open as readonly document in the left group and focus it (single click should be enough)
+      // Open as readonly document in the selected neighboring group and focus it (single click should be enough)
       const document = await vscode.workspace.openTextDocument(uri);
       await vscode.window.showTextDocument(document, {
-        viewColumn: targetViewColumn ?? vscode.ViewColumn.Beside,
+        viewColumn: targetViewColumn,
         preview: false,
         preserveFocus: false,
       });