Claude Code Not Working?
Hanging, 529 overloaded, auth errors, or no response? Claude Code depends on Anthropic's API — check it first.
Current Anthropic API Status
Claude Code uses Anthropic's Claude API. If the API is down, Claude Code is down. Check both:
What's Wrong? Diagnose Fast
Hanging or no response
Anthropic API is slow (check status), or your context is very long (100k+ tokens). Press Escape to cancel, then run /compact to compress context.
529 Overloaded error
Anthropic servers at capacity. Wait 30-60 seconds and retry. Try switching to claude-haiku for lower queue pressure during Sonnet overloads.
Authentication error
Invalid or expired API key. Check ANTHROPIC_API_KEY env var. Verify key validity at console.anthropic.com/settings/keys. Check billing balance.
Rate limit (429) error
Tier rate limit hit. Check your tier at console.anthropic.com/settings/limits. Claude Code is subject to the same rate limits as the API (tokens/min by tier).
Step-by-Step Fix
- 1
Check Anthropic API status first
Visit prismix.dev/service/anthropic or anthropic.statuspage.io. If there's an active incident, no local fix will help.
- 2
Verify API key and billing
In terminal:
echo $ANTHROPIC_API_KEY— it should print your key. Check billing at console.anthropic.com/settings/billing (low or zero balance = 401 errors). Regenerate the key if needed. - 3
Update Claude Code
Run:
npm update -g @anthropic-ai/claude-codeorclaude --versionto check your version. Older versions may fail due to API protocol changes. - 4
Compress context if session is large
Run
/compactin Claude Code to summarize and compress the conversation. Sessions with 100k+ tokens slow down dramatically and may time out. You can also check token usage with/status. - 5
Switch to Haiku for 529/overload errors
If Sonnet is overloaded (529), switch to Haiku temporarily:
claude --model claude-haiku-4-5. Haiku has significantly lower queue pressure and still handles most dev tasks well.
Error Code Reference
| Error | Meaning | Fix |
|---|---|---|
| 401 | Invalid/expired API key | Regenerate key at console.anthropic.com |
| 429 | Rate limit exceeded | Wait and retry; upgrade tier for higher limits |
| 529 | API overloaded | Wait 30-60s; switch to Haiku temporarily |
| 500 | Anthropic server error | Check anthropic.statuspage.io, retry |
| timeout | Context too long / API slow | /compact to reduce context; check API status |
Claude Code Plans and Rate Limits
| Plan | Access | Notes |
|---|---|---|
| API key (Tier 1-4) | Token-based billing | Limits at console.anthropic.com/settings/limits |
| Claude Pro ($20/mo) | 5× the free limits | Rate limited during peak; same 529 risk |
| Claude Max ($100/mo) | 25-50× the free limits | Better for heavy Claude Code use |
Claude Code with claude.ai subscription uses the same API pool as claude.ai web and mobile. Heavy parallel use compounds rate limits faster.
Get Alerted When Anthropic's API Goes Down
Star Anthropic on Prismix and get instant email or webhook alerts when the API experiences degradation — know before Claude Code starts erroring.
View Anthropic Status →Frequently Asked Questions
Why is Claude Code not working?
Most common causes: Anthropic API degradation (check prismix.dev/service/anthropic), invalid/expired API key, rate limit hit (429), server overload (529), or very long context causing timeouts (run /compact).
Is Claude Code down right now?
Claude Code depends on Anthropic's API. Check prismix.dev/service/anthropic or anthropic.statuspage.io. If the API is operational but Claude Code is still failing, the issue is local — check API key and billing.
Claude Code is hanging or not responding — what to do?
Press Escape to cancel. Check Anthropic API status. If in a long session, run /compact to compress context. For 529 errors, wait 30-60 seconds and switch to Haiku (claude --model claude-haiku-4-5) for lower queue pressure.
Claude Code 529 overloaded error — how to fix?
529 = Anthropic servers are at capacity. This is server-side, not your fault. Wait 30-60 seconds, then retry. Switch to claude-haiku-4-5 model which has lower queue pressure during Sonnet overload events. Check prismix.dev/service/anthropic for outage status.
Claude Code authentication error — API key invalid
Check ANTHROPIC_API_KEY is set (echo $ANTHROPIC_API_KEY). Verify the key at console.anthropic.com/settings/keys — it may have been revoked. Check billing balance at console.anthropic.com/settings/billing. If using claude.ai subscription, verify API access is enabled for your tier.