AI API errors / Anthropic (Claude)
Anthropic (Claude) · HTTP 504 · checked Oct 24, 2026
Anthropic 504 timeout_error: what it means and how to fix it
Retry: yes, with backoff504 timeout_error
What it meansThe request took too long while processing. Long non-streaming requests with a large max_tokens are the usual cause.
How to fix it
- Stream the response for long outputs; the SDK can collect the stream into a final message for you.
- Use the Message Batches API for very long jobs.
- Enable TCP keep-alive if you call the API directly.
Is it down right now?
Check our live status page or the official one.
Retry it properly
import anthropic
# The SDK retries 429, 5xx and connection errors with exponential backoff and honors retry-after.
client = anthropic.Anthropic(max_retries=6)
try:
msg = client.messages.create(model="claude-sonnet-5-5", max_tokens=1024,
messages=[{"role": "user", "content": "Hello"}])
except anthropic.RateLimitError as e: # 429 after all retries
print("still rate limited", e.response.headers.get("retry-after"))
except anthropic.APIStatusError as e: # 529 overloaded, 500, 504...
print(e.status_code, e.response.headers.get("request-id"))The official SDKs already retry connection errors, 429 and 5xx twice with exponential backoff and honor retry-after; raise max_retries for batch jobs.
Same kind of error at other providers
- OpenAI 500 server_error
- OpenAI 503 server_is_overloaded
- Google Gemini API 503 UNAVAILABLE
- Google Gemini API 500 INTERNAL
Other Anthropic (Claude) errors
- 529overloaded_error: Overloadedretry
- 429rate_limit_errorretry
- 400invalid_request_errorfix
- 400invalid_request_error: This model does not support assistant message prefill. The conversatiofix
- 400invalid_request_error: "thinking.type.enabled" is not supported for this model. Use "thinkingfix
- 400invalid_request_error: "thinking.type.disabled" is not supported for this model. Use "thinkinfix
- 400invalid_request_error: `thinking` or `redacted_thinking` blocks in the latest assistant messafix
- 400invalid_request_error: tool_choice: type "tool" and "any" are not supported for this model.fix
- 401authentication_errorfix
- 402billing_errorfix
- 403permission_errorfix
- 404not_found_error: The requested resource could not be found.fix
- 413request_too_largefix
- 500api_errorretry
Source
- Anthropic (Claude) error documentation: platform.claude.com/docs/en/api/errors (checked Oct 24, 2026)
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