Avoid broad at-command recursive searches

packages/cli/src/ui/hooks/atCommandProcessor.test.ts

@@ -551,6 +551,65 @@ describe('handleAtCommand', () => {
     });
   });
 
+  it('should skip recursive glob fallback for bare @ names', async () => {
+    const buildAndExecute = vi.fn().mockResolvedValue({
+      llmContent: 'No files found',
+      returnDisplay: 'No files found',
+    });
+    vi.mocked(mockConfig.getToolRegistry).mockReturnValue({
+      getTool: vi.fn((name: string) =>
+        name === 'glob' ? { buildAndExecute } : undefined,
+      ),
+    } as unknown as ToolRegistry);
+
+    const query = 'Ask @teammate for review';
+
+    const result = await handleAtCommand({
+      query,
+      config: mockConfig,
+      addItem: mockAddItem,
+      onDebugMessage: mockOnDebugMessage,
+      messageId: 134,
+      signal: abortController.signal,
+    });
+
+    expect(buildAndExecute).not.toHaveBeenCalled();
+    expect(mockOnDebugMessage).toHaveBeenCalledWith(
+      'Path teammate not found directly and does not look like a path. Skipping recursive glob search.',
+    );
+    expect(result).toEqual({
+      processedQuery: [{ text: query }],
+    });
+  });
+
+  it('should not treat @ in the middle of a word as an @ command', async () => {
+    const buildAndExecute = vi.fn().mockResolvedValue({
+      llmContent: 'No files found',
+      returnDisplay: 'No files found',
+    });
+    vi.mocked(mockConfig.getToolRegistry).mockReturnValue({
+      getTool: vi.fn((name: string) =>
+        name === 'glob' ? { buildAndExecute } : undefined,
+      ),
+    } as unknown as ToolRegistry);
+
+    const query = 'Connect to user@host before continuing.';
+
+    const result = await handleAtCommand({
+      query,
+      config: mockConfig,
+      addItem: mockAddItem,
+      onDebugMessage: mockOnDebugMessage,
+      messageId: 135,
+      signal: abortController.signal,
+    });
+
+    expect(buildAndExecute).not.toHaveBeenCalled();
+    expect(result).toEqual({
+      processedQuery: [{ text: query }],
+    });
+  });
+
   describe('git-aware filtering', () => {
     beforeEach(async () => {
       await fsPromises.mkdir(path.join(testRootDir, '.git'), {

packages/cli/src/ui/hooks/atCommandProcessor.ts

@@ -61,6 +61,12 @@ export function unescapeLiteralAt(text: string): string {
 export const AT_COMMAND_PATH_REGEX_SOURCE =
   '(?:(?:"(?:[^"]*)")|(?:\\\\.|[^ \\t\\n\\r,;!?()\\[\\]{}.]|\\.(?!$|[ \\t\\n\\r])))+';
 
+/**
+ * An @ reference can start at the beginning of input or after punctuation/space,
+ * but not in the middle of a word such as user@host or hello@file.
+ */
+export const AT_COMMAND_START_REGEX_SOURCE = '(?<![\\\\A-Za-z0-9_])@';
+
 interface HandleAtCommandParams {
   query: string;
   config: Config;
@@ -94,7 +100,7 @@ function parseAllAtCommands(
 
   // Create a new RegExp instance for each call to avoid shared state/lastIndex issues.
   const atCommandRegex = new RegExp(
-    `(?<!\\\\)@${AT_COMMAND_PATH_REGEX_SOURCE}`,
+    `${AT_COMMAND_START_REGEX_SOURCE}${AT_COMMAND_PATH_REGEX_SOURCE}`,
     'g',
   );
 
@@ -218,6 +224,19 @@ interface IgnoredFile {
   reason: 'git' | 'gemini' | 'both';
 }
 
+function shouldAttemptGlobFallback(pathName: string): boolean {
+  return (
+    pathName.includes('/') ||
+    pathName.includes('\\') ||
+    pathName.includes('.') ||
+    pathName.includes('*') ||
+    pathName.includes('?') ||
+    pathName.includes('[') ||
+    pathName.includes(']') ||
+    pathName.startsWith('~')
+  );
+}
+
 /**
  * Resolves file paths from @ commands, handling globs, recursion, and ignores.
  */
@@ -304,7 +323,11 @@ async function resolveFilePaths(
       // We also allow glob fallback for "unauthorized" results from resolveAtCommandPath,
       // as they might represent a relative path that matched an unauthorized file in one directory
       // but might have a valid match (via glob) in another.
-      if (config.getEnableRecursiveFileSearch() && globTool) {
+      if (!shouldAttemptGlobFallback(pathName)) {
+        onDebugMessage(
+          `Path ${pathName} not found directly and does not look like a path. Skipping recursive glob search.`,
+        );
+      } else if (config.getEnableRecursiveFileSearch() && globTool) {
         onDebugMessage(
           `Path ${pathName} not found directly, attempting glob search.`,
         );

packages/cli/src/ui/utils/commandUtils.test.ts

@@ -177,9 +177,12 @@ describe('commandUtils', () => {
       // referenced files are pre-loaded before the query is sent to the model.
       expect(isAtCommand('check:@file.py')).toBe(true);
       expect(isAtCommand('analyze(@file.py)')).toBe(true);
-      expect(isAtCommand('hello@file')).toBe(true);
-      expect(isAtCommand('text@path/to/file')).toBe(true);
-      expect(isAtCommand('user@host')).toBe(true);
+    });
+
+    it('should return false when @ is in the middle of a word', () => {
+      expect(isAtCommand('hello@file')).toBe(false);
+      expect(isAtCommand('text@path/to/file')).toBe(false);
+      expect(isAtCommand('user@host')).toBe(false);
     });
 
     it('should return false when query does not contain any @<path> pattern', () => {

packages/cli/src/ui/utils/commandUtils.ts

@@ -10,13 +10,16 @@ import type { SlashCommand } from '../commands/types.js';
 import fs from 'node:fs';
 import type { Writable } from 'node:stream';
 import type { Settings } from '../../config/settingsSchema.js';
-import { AT_COMMAND_PATH_REGEX_SOURCE } from '../hooks/atCommandProcessor.js';
+import {
+  AT_COMMAND_PATH_REGEX_SOURCE,
+  AT_COMMAND_START_REGEX_SOURCE,
+} from '../hooks/atCommandProcessor.js';
 
 // Pre-compiled regex for detecting @<path> patterns consistent with parseAllAtCommands.
 // Uses the same AT_COMMAND_PATH_REGEX_SOURCE so that isAtCommand is true whenever
 // parseAllAtCommands would find at least one atPath part.
 const AT_COMMAND_DETECT_REGEX = new RegExp(
-  `(?<!\\\\)@${AT_COMMAND_PATH_REGEX_SOURCE}`,
+  `${AT_COMMAND_START_REGEX_SOURCE}${AT_COMMAND_PATH_REGEX_SOURCE}`,
 );
 
 /**