Why is Claude Code not working?

The most common reasons Claude Code stops working: expired API key, exhausted usage credits, network proxy blocking the connection, or a stale Claude Code version. Run `claude --version` to check, `claude auth logout && claude auth login` to refresh credentials, and `npm update -g @anthropic-ai/claude-code` to upgrade.

How do I fix Claude Code authentication errors?

Run `claude auth logout` then `claude auth login` to go through the OAuth flow again. If you're behind a corporate proxy, set ANTHROPIC_BASE_URL or configure your proxy settings. For API key auth, verify the key starts with sk-ant- and has not been revoked in your Anthropic Console.

Why is Claude Code so slow?

Slowness usually comes from large context windows (too many files loaded), rate limiting, or network latency. Fix: use /compact to compress context, add noisy directories to .claudeignore, and check your network connection to api.anthropic.com.

How do I fix 'context window exceeded' in Claude Code?

Run /compact to summarize the conversation history, then continue. For long sessions, start fresh with /clear or open a new terminal. Use a .claudeignore file to exclude large directories (node_modules, .git, dist) from the context.

Claude Code is not finding my files — how do I fix it?

Claude Code reads from the current working directory. Make sure you launched it from your project root. Check that the file isn't excluded by .gitignore or .claudeignore. For monorepos, run claude from the workspace root so it can see all packages.

How do I fix Claude Code VSCode extension issues?

Reload the VSCode window (Ctrl+Shift+P → Reload Window), then check the Claude Code output panel for errors. Ensure the CLI is installed globally (npm install -g @anthropic-ai/claude-code) since the extension shells out to the CLI. Check VSCode's Extensions panel that Claude Code is enabled for the current workspace.

Claude Code Troubleshooting — Fix Common Errors & Issues

Refresh auth

claude auth logout && claude auth login

Compress context

/compact

Update CLI

npm update -g @anthropic-ai/claude-code

Clear & restart

/clear (then re-open)

Check version

claude --version

Debug mode

claude --debug

Authentication & Login Problems

Error: "Not authenticated" or login loop

Token expired, credentials corrupted, or OAuth consent revoked.

Run claude auth logout to clear cached tokens
Run claude auth login — a browser tab will open for OAuth
Complete the consent screen; credentials are stored in ~/.claude/
If browser doesn't open, copy the URL from terminal and paste manually

API key authentication fails (sk-ant-…)

Key revoked, wrong permissions, or pasted with extra whitespace.

Go to console.anthropic.com → API Keys and confirm the key is active
Create a new key if the old one was compromised or expired
Export cleanly: export ANTHROPIC_API_KEY="sk-ant-your-key-here"
Verify: echo $ANTHROPIC_API_KEY | head -c 10 — should show sk-ant-api

Corporate proxy or VPN blocking connections

HTTPS inspection or firewall blocking api.anthropic.com.

Set proxy: export HTTPS_PROXY=http://proxy.company.com:8080
Or use ANTHROPIC_BASE_URL to point to an internal gateway
Ask IT to whitelist api.anthropic.com on port 443
Test connectivity: curl -I https://api.anthropic.com

Slow Performance & Timeouts

Claude Code responding very slowly

Large context window, rate limiting, or high API latency.

Run /compact to compress conversation history — biggest single fix
Create .claudeignore to exclude node_modules/, dist/, .git/, *.lock
Check status.anthropic.com for API incidents
If rate limited, wait 60s or upgrade your usage tier

.claudeignore example:
node_modules/
dist/
build/
.next/
*.lock
*.log
coverage/
.git/

Request timeout errors

Long-running operations hitting the default timeout.

Break large tasks into smaller chunks (ask Claude to plan first, then execute step by step)
For very large codebases, run Claude from a sub-directory rather than the repo root
Set CLAUDE_TIMEOUT_MS=120000 (2 min) for slower connections

Context Window & Memory Errors

"Context window exceeded" or truncated responses

Conversation history + open files exceed the model's token limit.

Run /compact immediately — Claude will summarize the conversation so far
Use /clear to start a brand new session if /compact isn't enough
Break work into focused sessions: one session per feature/bug
Don't paste entire files into the chat — let Claude read them with tools

Claude "forgets" earlier instructions mid-session

Instructions scrolled out of the active context window.

Put persistent instructions in CLAUDE.md at the project root — Claude always loads this
Use /compact periodically to keep the important context fresh
See the CLAUDE.md memory guide for structuring persistent instructions

VSCode Extension Issues

Claude Code panel not appearing or blank in VSCode

Extension or CLI version mismatch, or extension not activated.

Press Ctrl+Shift+P → "Developer: Reload Window"
Check Extensions panel: verify Claude Code is installed and enabled
Update CLI: npm update -g @anthropic-ai/claude-code
Open VSCode's Output panel and select "Claude Code" from the dropdown for error details

Inline suggestions not appearing

Inline diff mode disabled, or conflicting with GitHub Copilot.

Enable: Settings → Extensions → Claude Code → Enable Inline Suggestions
If Copilot is installed, pause it temporarily — both can conflict for the same keybinding
Try the keyboard shortcut Ctrl+K (Win/Linux) or Cmd+K (Mac) to trigger Claude manually

Extension says "Cannot find claude binary"

CLI not installed globally or not on VSCode's PATH.

Install globally: npm install -g @anthropic-ai/claude-code
Verify: which claude — should return a path
If VSCode uses a different PATH, set Settings → Claude Code → CLI Path to the absolute path
Restart VSCode after installing — extensions don't pick up PATH changes in the current session

MCP (Model Context Protocol) Issues

MCP server not connecting or tools missing

Server process crashed, misconfigured JSON, or Node version mismatch.

Run the MCP server manually in a terminal to see its startup errors
Validate your ~/.claude/mcp.json with cat ~/.claude/mcp.json | python3 -m json.tool
Check that node ≥ v18 is on your PATH: node --version
Try claude mcp list to see registered servers and their status

MCP tools appear but return errors

Server running but tool inputs failing schema validation or missing credentials.

Run Claude with --debug to see raw MCP request/response logs
Check the server's args in mcp.json — missing env vars are the most common cause
See the full MCP setup guide for per-server configuration

Git & Permission Errors

Claude Code won't run git commands

Permission mode set to "default" blocks shell commands without explicit approval.

Approve git commands when prompted, or use --dangerously-skip-permissions in trusted environments
Add git to your project's allowed commands in CLAUDE.md: # Allowed: git add, git commit, git push
Check claude settings for current permission level

"Permission denied" writing files

Running Claude in a directory with restricted permissions.

Check permissions: ls -la in the target directory
Fix ownership: sudo chown -R $USER:$USER .
Never run Claude as root — it will warn you and refuse certain operations

Frequently Asked Questions

Claude Code installed but the `claude` command is not found

Your shell's PATH doesn't include npm's global bin directory. Run npm config get prefix to find the npm prefix, then add <prefix>/bin to your PATH in ~/.bashrc or ~/.zshrc.

echo 'export PATH="$(npm config get prefix)/bin:$PATH"' >> ~/.zshrc
source ~/.zshrc
which claude  # should now return a path

How do I completely reset Claude Code?

To clear all state: rm -rf ~/.claude/ then re-authenticate with claude auth login. This removes all conversations, settings, and credentials — use as a last resort.

Claude Code is producing different results than before

Claude's responses are non-deterministic by design. For consistent results: pin exact instructions in CLAUDE.md, use specific task descriptions rather than vague ones, and break complex tasks into smaller deterministic steps.

How do I report a Claude Code bug?

File issues at github.com/anthropics/claude-code/issues. Include: claude --version output, OS version, the exact command or prompt that failed, and the error message. For security issues use Anthropic's responsible disclosure process instead.

Claude Code says I'm out of credits — what do I do?

Go to console.anthropic.com → Billing and add credits or upgrade your plan. Claude Code uses the same API credits as direct API calls. There's no separate "Claude Code" billing — it all comes from your Anthropic account balance.

Still Stuck?

These resources help when the above fixes don't resolve your issue:

status.anthropic.com — check for API outages before assuming a local issue
GitHub Issues — search for your error; many issues have existing fixes in the comments
Anthropic Discord — #claude-code channel for community help
Claude Code best practices — avoid the issues before they happen
Installation guide — verify your setup is correct from the start