🔑 Quick Answer: What Is the Claude Code Session Expired Error? When you see a "session expired" error, your authentication token is no longer valid. Claude Code uses a browser-based OAuth flow — when that token expires or becomes corrupted, requests are rejected. Fastest fix: Sign out → Clear cached credentials → Authenticate again. Most common causes: expired tokens, network interruptions, account changes, corrupted local auth data, macOS keychain issues, or OAuth callback timeouts. |
1. What Is the Claude Code Session Expired Error?
The Claude Code session expired error appears when Claude Code can no longer verify your login session with Anthropic's authentication system. Claude Code uses a browser-based OAuth flow: the CLI opens a browser window, you authenticate, and the browser redirects a token back to the CLI. When that token expires, becomes corrupted, or the OAuth callback fails, you lose access entirely.
When this happens, Claude Code loses the ability to:
Send requests to Anthropic's API
Authenticate your account and validate permissions
Access Claude services and sync subscriptions
Generate code or use AI features in VS Code
Connect through the CLI
📌 Official Source — Anthropic Support According to Anthropic's official troubleshooting documentation, login errors are most commonly caused by VPN usage, browser extensions, or cached cookies. Their recommended first steps are: disable your VPN, turn off browser extensions, and clear cache/cookies. Always check status.claude.com to rule out a service-wide incident before troubleshooting locally. |
2. Why Does This Error Happen? (All Root Causes)
Multiple factors can trigger a Claude Code session expired or login failed error. Understanding the root cause helps you apply the right fix faster.
2.1 OAuth Callback Timeout (Most Common)
Claude Code's authentication relies on a browser-based OAuth flow. The CLI opens a browser, you log in, and the browser sends a token back to the CLI — but only within a ~60-second window. Common failure points include:
Too many browser tabs slowing down the redirect
The browser not returning focus to the CLI in time
Slow network connections exceeding the callback timeout
Fix: Close extra browser tabs, retry the login, or use an API key to bypass OAuth entirely.
2.2 Expired Authentication Tokens
Most login systems use temporary access tokens with built-in expiry. When the token expires, Claude Code rejects all requests and prompts re-authentication. This is the most frequent cause of random logouts during active sessions.
2.3 Cached Credential Corruption
Stored authentication data in ~/.claude/cache or the macOS keychain can become corrupted after:
System crashes or forced shutdowns
Interrupted updates or disk write errors
SSH sessions where the macOS keychain was locked
Corrupted credentials create repeated login loops that won't resolve without clearing the cache.
2.4 macOS Keychain Issues (Platform-Specific)
Claude Code stores credentials in the macOS keychain by default. When the keychain is locked which happens automatically in SSH sessions or after system sleep Claude Code cannot read or write credentials. This causes a silent authentication failure that looks identical to a token expiry.
security unlock-keychain ~/Library/Keychains/login.keychain-db
2.5 DNS Resolution Failures
If your machine cannot resolve claude.ai or auth.anthropic.com, the OAuth flow is blocked before it even begins. This is common in corporate environments with strict DNS filtering or split-horizon DNS configurations.
nslookup claude.ainslookup auth.anthropic.com
2.6 Account Changes
Password changes, email updates, subscription modifications, or MFA changes invalidate existing sessions. After any account change on the Anthropic website, all existing Claude Code sessions become invalid and require reauthentication.
2.7 Network & Proxy Interruptions
Claude Code continuously validates authentication. These network conditions can interrupt token validation:
VPN instability or reconnections
Corporate firewalls blocking Anthropic authentication endpoints
Proxy misconfigurations or TLS inspection interfering with tokens
DNS failures or high packet loss
2.8 Google SSO Issues
Google SSO login has known intermittent issues where the browser redirect completes but the CLI does not receive the token. If you use Google to sign in and authentication consistently fails, switch to email/password login as a workaround.
2.9 Outdated Claude Code Versions
Older Claude Code releases may use deprecated authentication flows that are no longer supported. Always update before troubleshooting authentication failures.
2.10 Anthropic Server-Side Issues
Occasionally, Anthropic's infrastructure experiences elevated errors or capacity constraints. Before spending time on local troubleshooting, verify the service status:
status.anthropic.com — official status page
status.claude.com — Claude-specific status
Anthropic Discord and X/Twitter for real-time community reports
3. Common Error Messages Explained
Use this reference table to identify your specific error and its severity:
Error Message | Meaning | Severity | Recommended Fix |
Session Expired | Authentication token expired | Medium | Re-login |
Authentication Failed | Login verification failed | High | Reauthenticate |
Invalid Credentials | Stored credentials rejected | High | Clear cache |
Login Session Expired | Session timeout reached | Medium | Sign in again |
Unauthorized Request | Token invalid | High | Refresh credentials |
Failed Authentication | Auth system rejected request | High | Reconnect account |
Token Expired | Access token no longer valid | Medium | Generate new session |
Sign In Required | No valid authentication detected | Low | Login again |
OAuth callback timeout | CLI stopped listening for redirect | Medium | Close tabs & retry |
Keychain access denied | macOS keychain locked (SSH/sleep) | High | Unlock keychain |
Error 500 during login | Server-side issue at Anthropic | High | Check status page |
4. Quick Fix Checklist (Try These First)
Before attempting advanced solutions, run through this checklist. Most users resolve the problem here:
Restart Claude Code
Sign out and sign back in
Verify internet connectivity (ping anthropic.com)
Disable VPN temporarily
Update Claude Code to the latest version
Update VS Code (if using the extension)
Restart your computer
Check Anthropic account access via the website
Clear cached authentication data (~/.claude/cache)
Check status.anthropic.com for active incidents
Try email/password login if Google SSO is failing
5. Step-by-Step Fixes
1. | Reauthenticate Claude Code (Start Here) Replaces your expired token with a fresh authentication session. Use whenever 'session expired' or 'login expired' appears. |
Steps:
Open Claude Code and sign out
Close Claude Code completely
Reopen and complete the full login flow
Verify connection is restored
2. | Clear Cached Credentials Removes damaged authentication files that cause repeated login loops. |
rm -rf ~/.claude/cache
Then restart Claude Code and log in again. This forces Claude to generate fresh authentication data.
3. | Unlock macOS Keychain (macOS Only) Required when running in SSH sessions or after system sleep — the keychain is locked by default. |
security unlock-keychain ~/Library/Keychains/login.keychain-db |
After unlocking, retry authentication. If the issue persists in headless/SSH environments, use API key authentication instead (Fix #8).
4. | Fix DNS Resolution Issues Checks whether authentication endpoints are reachable from your machine. |
nslookup claude.ainslookup auth.anthropic.comping anthropic.com |
If DNS resolution fails, switch to Google DNS (8.8.8.8) or Cloudflare DNS (1.1.1.1) and retry. In corporate environments, contact your network administrator to whitelist Anthropic authentication endpoints.
5. | Verify Anthropic Account Access Confirms the issue is local, not an account-level problem. |
Steps:
Sign in at anthropic.com through your browser
Confirm subscription is active
Verify MFA/2FA completion
Check for any security alerts or account flags
If browser login fails, Claude Code will also fail — resolve the account issue first.
6. | Update Claude Code Authentication bugs are frequently patched in updates. Always update before deeper troubleshooting |
npm update -g @anthropic-ai/claude-code# or check your package manager for the latest version |
7. | Fix VS Code Extension Issues Use when authentication fails only inside VS Code but works in the CLI. |
Steps:
Disable the Claude extension in VS Code
Restart VS Code
Clear extension storage data
Reinstall the Claude extension
Sign in again
Also check for conflicting extensions: authentication managers, proxy extensions, security tools, or workspace sync tools can interfere.
8. | Use API Key Authentication (Bypass OAuth) The most reliable method for automated workflows, SSH environments, and CI/CD pipelines. |
export ANTHROPIC_API_KEY=your_api_key_here# Add to ~/.bashrc or ~/.zshrc to persist
API key authentication bypasses the OAuth browser flow entirely, eliminating callback timeouts, keychain issues, and DNS-related failures. Get your key from console.anthropic.com.
9. | Resolve Proxy and Firewall Issues Required in corporate networks that intercept or block Anthropic authentication endpoints. |
Diagnostics:
Temporarily disconnect VPN and retry authentication
Switch to a mobile hotspot to isolate network filtering
Ask IT to whitelist auth.anthropic.com and claude.ai
Check if TLS inspection is stripping authentication headers
6. Advanced CLI Troubleshooting
For developers using terminal-based workflows, these commands provide deeper diagnostics.
Check Authentication Status
claude auth status |
Look for: expired sessions, invalid credentials, or missing tokens.
Check Environment Variables
env | grep ANTHROPIC |
Verify correct values, no duplicates, and no obsolete or conflicting tokens.
Full Reauthentication via CLI
claude logoutclaude login |
Clear All Auth Data and Retry
claude logoutrm -rf ~/.claude/cacheclaude login |
7. Authentication Diagnostics
Use this table to match your symptoms to the most likely cause:
Symptom | Likely Cause | Recommended Fix |
Random logout during active session | Token expiration | Reauthenticate |
Stuck in login loop | Corrupted credentials / cache | Clear ~/.claude/cache |
Unauthorized error on requests | Invalid or expired token | Log out and log in |
'Keychain access denied' on macOS | Keychain locked in SSH/sleep | Run security unlock-keychain |
Browser opens but CLI says 'timed out' | OAuth callback timeout | Close tabs, retry, or use API key |
Google SSO completes but login fails | Google auth redirect issue | Switch to email/password login |
DNS resolution hangs indefinitely | DNS filtering or misconfiguration | Check nslookup, switch DNS |
Works in CLI but not VS Code | Extension auth corruption | Reinstall Claude extension |
Works on hotspot but not office network | Corporate firewall/proxy | Contact IT, whitelist endpoints |
Authentication fails after account change | Password/MFA change invalidates session | Reauthenticate from scratch |
Error 500 during login | Anthropic server-side issue | Check status.anthropic.com |
8. VS Code-Specific Authentication Fixes
Some users experience authentication failures exclusively inside VS Code while the CLI works fine. This points to extension-level issues rather than token or network problems.
Clear VS Code Extension Storage
VS Code sometimes stores damaged authentication tokens in its extension storage directory. Clearing this forces a fresh credential fetch.
Close VS Code completely
Navigate to the VS Code extensions directory
Remove Claude-related storage data
Restart VS Code and reauthenticate
Disable Conflicting Extensions
The following extension types are known to interfere with Claude Code authentication in VS Code:
Authentication managers (e.g., Keychain integrations)
Proxy or network management extensions
Security or firewall extensions
Workspace sync tools
Test by disabling all other extensions and verifying Claude Code works independently. Re-enable extensions one at a time to identify the conflict.
Verify Extension Version Compatibility
After a VS Code update or a Claude Code release, extension API compatibility can break. Reinstall the extension fresh after any major update to both tools.
9. Is It Authentication or a Service Outage?
An important distinction: capacity constraints at Anthropic look like authentication errors from the user's perspective but require a completely different response.
⚠️ Capacity Constraints vs. Authentication Failures
Anthropic's official support documentation distinguishes between two types of failures: • Capacity Constraints: High demand causes temporary rejections. These do NOT appear on the status page because they represent normal load management. Try again in a few minutes. • Authentication Failures: Your credentials are invalid. These persist across retries and require the fixes in this guide. • Service Incidents: Actual technical problems. These DO appear on status.anthropic.com. Check status.anthropic.com first. If no incidents are listed but errors persist, it is likely a local authentication issue. |
10. Claude Code Authentication Methods Compared
Feature | Claude Code Login (OAuth) | API Key Authentication |
Ease of Setup | Easy — browser-based flow | Medium — manual key management |
Session Expiration | Yes — tokens expire | Rare — keys are long-lived |
macOS Keychain Required | Yes (by default) | No |
Works in SSH/Headless | Requires workarounds | Yes — fully supported |
Works in CI/CD | Not recommended | Recommended |
Enterprise SSO Support | Yes (via browser) | Depends on setup |
OAuth Callback Required | Yes | No |
Security Level | High | High (store keys securely) |
11. Best Practices to Prevent Session Expiration
Keep Claude Code Updated
New releases frequently include authentication improvements, token refresh fixes, and security updates. Set up automatic updates where possible.
Use API Key Authentication for Automated Workflows
For CI/CD pipelines, scripts, SSH environments, and headless servers, API key authentication is significantly more reliable than the OAuth browser flow.
Avoid Multiple Concurrent Logins
Using several devices simultaneously can occasionally invalidate sessions. Anthropic's authentication system may enforce single-session policies in some configurations.
Maintain Stable Network Connectivity
Token refresh processes depend on uninterrupted network access to Anthropic endpoints. Avoid authentication attempts on unstable connections.
Sign Out Gracefully
Avoid forcing application shutdowns mid-session. Graceful sign-outs reduce the chance of credential corruption in the local cache.
Unlock Keychain Before SSH Sessions (macOS)
If you regularly use Claude Code over SSH on macOS, unlock the keychain at the start of each session or switch to API key authentication permanently.
12. Expert Troubleshooting Workflow
Follow this decision tree in order to resolve authentication issues efficiently:
Step 1 — See 'Session Expired'? → Log out → Log in again → Test connection |
Step 2 — Login Fails Again? → Clear ~/.claude/cache → Restart application → Retry authentication |
Step 3 — Authentication Still Fails? → Check status.anthropic.com → Test on mobile hotspot → Disable VPN → Verify account at anthropic.com |
Step 4 — macOS / SSH Environment? → Run: security unlock-keychain → Or switch to API key authentication |
Step 5 — Only VS Code Fails? → Reinstall the Claude extension → Clear extension data → Reauthenticate |
Step 6 — Nothing Works? → Update all software → Try API key authentication → Contact Anthropic support with logs and diagnostic output. |
The most common cause is token expiration. Authentication tokens have a built-in expiry period. When the token expires, Claude Code requires reauthentication. This often appears as random logouts during active sessions.
Sign out, clear ~/.claude/cache, restart Claude Code, and complete a fresh login. This generates new authentication credentials and clears any corrupted state.
Claude Code's login flow opens a browser window for you to authenticate. The CLI waits ~60 seconds for the browser to redirect the authentication token back. If that redirect doesn't complete in time (due to slow network, too many browser tabs, or browser focus issues), the timeout triggers. Fix: close extra tabs and retry, or use API key authentication.
The VS Code extension maintains its own authentication storage, separate from the CLI. If that storage becomes corrupted, or if an extension conflict exists, VS Code authentication fails while the CLI continues to work. Reinstall the Claude extension and clear its storage data.
Yes. Damaged cached authentication data in ~/.claude/cache is one of the most common causes of repeated login failures and login loops. Clearing this directory forces Claude Code to generate fresh credentials.
Sometimes, but it should not be your first step. Reauthentication and cache clearing are faster and resolve the majority of issues. Reinstall only after other fixes have failed.
Yes. VPN instability, reconnections, or split-tunneling misconfigurations can interrupt token validation mid-session. Additionally, some VPNs route traffic through servers that block Anthropic authentication endpoints. Test by disconnecting the VPN and retrying.
Stored credentials may become incompatible with newer authentication mechanisms in updated versions. After a major update, clear your cached credentials and reauthenticate from scratch.
Yes. Password changes, email updates, MFA changes, and subscription modifications all invalidate existing authentication sessions. After any account change, expect to reauthenticate in all environments.
Verify account access directly on the Anthropic website, test on a different network, update all software, switch to API key authentication, and contact Anthropic support with your diagnostic logs.
14. Common Mistakes to Avoid
Mistake | Consequence | Better Approach |
Reinstalling immediately | Wastes time; rarely fixes auth issues | Start with reauthentication |
Ignoring updates | Known authentication bugs persist | Update before troubleshooting |
Keeping stale credentials | Login loops continue indefinitely | Clear ~/.claude/cache |
Using multiple accounts simultaneously | Session conflicts and unexpected logouts | Use one account at a time |
Forcing app shutdown mid-session | Credential file corruption | Always sign out gracefully |
Debugging before checking service status | Troubleshooting a problem that doesn't exist locally | Check status.anthropic.com first |
Using Google SSO when it's failing | Persistent redirect failures | Switch to email/password login |
Ignoring keychain on macOS | Silent authentication failures in SSH | Unlock keychain or use API key |
Sources & References Anthropic Official Support: support.claude.com | Anthropic Status: status.anthropic.com Claude Code Troubleshooting Docs: docs.anthropic.com | Remote OpenClaw Auth Guide | AdVenture Media Status Guide. |