fix(cli): use active sessionId in useLogger and improve resume robustness (#22606)

packages/cli/src/config/config.ts

@@ -244,10 +244,11 @@ export async function parseArguments(
             // When --resume passed without a value (`gemini --resume`): value = "" (string)
             // When --resume not passed at all: this `coerce` function is not called at all, and
             //   `yargsInstance.argv.resume` is undefined.
-            if (value === '') {
+            const trimmed = value.trim();
+            if (trimmed === '') {
               return RESUME_LATEST;
             }
-            return value;
+            return trimmed;
           },
         })
         .option('list-sessions', {

packages/cli/src/gemini.tsx

@@ -647,7 +647,7 @@ export async function main() {
       process.exit(ExitCodes.FATAL_INPUT_ERROR);
     }
 
-    const prompt_id = Math.random().toString(16).slice(2);
+    const prompt_id = sessionId;
     logUserPrompt(
       config,
       new UserPromptEvent(

packages/cli/src/ui/hooks/useLogger.test.tsx

@@ -0,0 +1,62 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { renderHook } from '../../test-utils/render.js';
+import { waitFor } from '../../test-utils/async.js';
+import { useLogger } from './useLogger.js';
+import {
+  sessionId as globalSessionId,
+  Logger,
+  type Storage,
+  type Config,
+} from '@google/gemini-cli-core';
+import { ConfigContext } from '../contexts/ConfigContext.js';
+import type React from 'react';
+
+// Mock Logger
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...actual,
+    Logger: vi.fn().mockImplementation((id: string) => ({
+      initialize: vi.fn().mockResolvedValue(undefined),
+      sessionId: id,
+    })),
+  };
+});
+
+describe('useLogger', () => {
+  const mockStorage = {} as Storage;
+  const mockConfig = {
+    getSessionId: vi.fn().mockReturnValue('active-session-id'),
+  } as unknown as Config;
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it('should initialize with the global sessionId by default', async () => {
+    const { result } = renderHook(() => useLogger(mockStorage));
+
+    await waitFor(() => expect(result.current).not.toBeNull());
+    expect(Logger).toHaveBeenCalledWith(globalSessionId, mockStorage);
+  });
+
+  it('should initialize with the active sessionId from ConfigContext when available', async () => {
+    const wrapper = ({ children }: { children: React.ReactNode }) => (
+      <ConfigContext.Provider value={mockConfig}>
+        {children}
+      </ConfigContext.Provider>
+    );
+
+    const { result } = renderHook(() => useLogger(mockStorage), { wrapper });
+
+    await waitFor(() => expect(result.current).not.toBeNull());
+    expect(Logger).toHaveBeenCalledWith('active-session-id', mockStorage);
+  });
+});

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

@@ -4,17 +4,25 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { useState, useEffect } from 'react';
-import { sessionId, Logger, type Storage } from '@google/gemini-cli-core';
+import { useState, useEffect, useContext } from 'react';
+import {
+  sessionId as globalSessionId,
+  Logger,
+  type Storage,
+} from '@google/gemini-cli-core';
+import { ConfigContext } from '../contexts/ConfigContext.js';
 
 /**
  * Hook to manage the logger instance.
  */
-export const useLogger = (storage: Storage) => {
+export const useLogger = (storage: Storage): Logger | null => {
   const [logger, setLogger] = useState<Logger | null>(null);
+  const config = useContext(ConfigContext);
 
   useEffect(() => {
-    const newLogger = new Logger(sessionId, storage);
+    const activeSessionId = config?.getSessionId() ?? globalSessionId;
+    const newLogger = new Logger(activeSessionId, storage);
+
     /**
      * Start async initialization, no need to await. Using await slows down the
      * time from launch to see the gemini-cli prompt and it's better to not save
@@ -26,7 +34,7 @@ export const useLogger = (storage: Storage) => {
         setLogger(newLogger);
       })
       .catch(() => {});
-  }, [storage]);
+  }, [storage, config]);
 
   return logger;
 };

packages/cli/src/utils/sessionUtils.test.ts

@@ -239,6 +239,44 @@ describe('SessionSelector', () => {
     expect(result.sessionData.messages[0].content).toBe('Latest session');
   });
 
+  it('should resolve session by UUID with whitespace (trimming)', async () => {
+    const sessionId = randomUUID();
+
+    // Create test session files
+    const chatsDir = path.join(tmpDir, 'chats');
+    await fs.mkdir(chatsDir, { recursive: true });
+
+    const session = {
+      sessionId,
+      projectHash: 'test-hash',
+      startTime: '2024-01-01T10:00:00.000Z',
+      lastUpdated: '2024-01-01T10:30:00.000Z',
+      messages: [
+        {
+          type: 'user',
+          content: 'Test message',
+          id: 'msg1',
+          timestamp: '2024-01-01T10:00:00.000Z',
+        },
+      ],
+    };
+
+    await fs.writeFile(
+      path.join(
+        chatsDir,
+        `${SESSION_FILE_PREFIX}2024-01-01T10-00-${sessionId.slice(0, 8)}.json`,
+      ),
+      JSON.stringify(session, null, 2),
+    );
+
+    const sessionSelector = new SessionSelector(config);
+
+    // Test resolving by UUID with leading/trailing spaces
+    const result = await sessionSelector.resolveSession(`  ${sessionId}  `);
+    expect(result.sessionData.sessionId).toBe(sessionId);
+    expect(result.sessionData.messages[0].content).toBe('Test message');
+  });
+
   it('should deduplicate sessions by ID', async () => {
     const sessionId = randomUUID();
 

packages/cli/src/utils/sessionUtils.ts

@@ -57,10 +57,14 @@ export class SessionError extends Error {
   /**
    * Creates an error for when a session identifier is invalid.
    */
-  static invalidSessionIdentifier(identifier: string): SessionError {
+  static invalidSessionIdentifier(
+    identifier: string,
+    chatsDir?: string,
+  ): SessionError {
+    const dirInfo = chatsDir ? ` in ${chatsDir}` : '';
     return new SessionError(
       'INVALID_SESSION_IDENTIFIER',
-      `Invalid session identifier "${identifier}".\n  Use --list-sessions to see available sessions, then use --resume {number}, --resume {uuid}, or --resume latest.`,
+      `Invalid session identifier "${identifier}".\n  Searched for sessions${dirInfo}.\n  Use --list-sessions to see available sessions, then use --resume {number}, --resume {uuid}, or --resume latest.`,
     );
   }
 }
@@ -416,6 +420,7 @@ export class SessionSelector {
    * @throws Error if the session is not found or identifier is invalid
    */
   async findSession(identifier: string): Promise<SessionInfo> {
+    const trimmedIdentifier = identifier.trim();
     const sessions = await this.listSessions();
 
     if (sessions.length === 0) {
@@ -430,24 +435,28 @@ export class SessionSelector {
 
     // Try to find by UUID first
     const sessionByUuid = sortedSessions.find(
-      (session) => session.id === identifier,
+      (session) => session.id === trimmedIdentifier,
     );
     if (sessionByUuid) {
       return sessionByUuid;
     }
 
     // Parse as index number (1-based) - only allow numeric indexes
-    const index = parseInt(identifier, 10);
+    const index = parseInt(trimmedIdentifier, 10);
     if (
       !isNaN(index) &&
-      index.toString() === identifier &&
+      index.toString() === trimmedIdentifier &&
       index > 0 &&
       index <= sortedSessions.length
     ) {
       return sortedSessions[index - 1];
     }
 
-    throw SessionError.invalidSessionIdentifier(identifier);
+    const chatsDir = path.join(
+      this.config.storage.getProjectTempDir(),
+      'chats',
+    );
+    throw SessionError.invalidSessionIdentifier(trimmedIdentifier, chatsDir);
   }
 
   /**
@@ -458,8 +467,9 @@ export class SessionSelector {
    */
   async resolveSession(resumeArg: string): Promise<SessionSelectionResult> {
     let selectedSession: SessionInfo;
+    const trimmedResumeArg = resumeArg.trim();
 
-    if (resumeArg === RESUME_LATEST) {
+    if (trimmedResumeArg === RESUME_LATEST) {
       const sessions = await this.listSessions();
 
       if (sessions.length === 0) {
@@ -475,7 +485,7 @@ export class SessionSelector {
       selectedSession = sessions[sessions.length - 1];
     } else {
       try {
-        selectedSession = await this.findSession(resumeArg);
+        selectedSession = await this.findSession(trimmedResumeArg);
       } catch (error) {
         // SessionError already has detailed messages - just rethrow
         if (error instanceof SessionError) {
@@ -483,7 +493,7 @@ export class SessionSelector {
         }
         // Wrap unexpected errors with context
         throw new Error(
-          `Failed to find session "${resumeArg}": ${error instanceof Error ? error.message : String(error)}`,
+          `Failed to find session "${trimmedResumeArg}": ${error instanceof Error ? error.message : String(error)}`,
         );
       }
     }