Anthropic API SSE Stream 中断时状态码错误为 200 而非 529

What this error means

APIStatusError: Status code 200 (expected 529) — mid-stream 'overloaded_error' event not properly mapped in streaming response is a Anthropic API failure pattern reported for developers trying to 修复 anthropic claude api 流式调用中 sse 中断错误事件返回 http 200 而非正确的 529 overloaded 状态码的问题. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

anthropic-sdk-python #1258 明确描述：SSE 错误事件中 _streaming.py 传递原始 HTTP 200 response 给 _make_status_error，导致错误对象的 status_code 始终为 200。SDK 维护者已通过 PR #1262/#1263/#1269 逐步修复（https://github.com/anthropics/anthropic-sdk-python/issues/1258）。这是典型的 429/529 生产问题场景。Category mapping: 直接对应 Anthropic API。

Common causes

• anthropic-sdk-python #1258 明确描述：SSE 错误事件中 _streaming.py 传递原始 HTTP 200 response 给 _make_status_error，导致错误对象的 status_code 始终为 200。SDK 维护者已通过 PR #1262/#1263/#1269 逐步修复（https://github.com/anthropics/anthropic-sdk-python/issues/1258）。这是典型的 429/529 生产问题场景。Category mapping: 直接对应 Anthropic API。

Quick fixes

1. Confirm the exact error signature matches APIStatusError: Status code 200 (expected 529) — mid-stream 'overloaded_error' event not properly mapped in streaming response.
2. Check the Anthropic API account, local tool state, and provider configuration involved in the failing workflow.
3. Reduce request pressure, check quota or plan limits, and retry with backoff instead of immediate repeated requests.

Platform/tool-specific checks

• Verify the command, editor, extension, or API client that produced the error.
• Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
• Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

1. Capture the exact error message and the command, editor action, or request that triggered it.
2. Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
3. Review the source evidence below and compare it with your environment.
4. Apply one change at a time and rerun the smallest failing action.
5. Keep the working fix documented for the team or deployment environment.

How to prevent it

• Keep provider/tool configuration documented.
• Record non-secret diagnostics such as tool version, provider name, model name, and command path.
• Add a lightweight check before CI or production workflows depend on the tool.

Sources checked

• https://github.com/anthropics/anthropic-sdk-python/issues/1258
• https://github.com/anthropics/anthropic-sdk-python/pull/1262
• https://github.com/anthropics/anthropic-sdk-python/pull/1263

Evidence note: anthropic-sdk-python #1258 明确描述：SSE 错误事件中 _streaming.py 传递原始 HTTP 200 response 给 _make_status_error，导致错误对象的 status_code 始终为 200。SDK 维护者已通过 PR #1262/#1263/#1269 逐步修复（https://github.com/anthropics/anthropic-sdk-python/issues/1258）。这是典型的 429/529 生产问题场景。Category mapping: 直接对应 Anthropic API。

Related errors

• Anthropic API

FAQ

What should I check first?

Start with the exact APIStatusError: Status code 200 (expected 529) — mid-stream 'overloaded_error' event not properly mapped in streaming response text and the smallest action that reproduces it.

Can I ignore this error?

No. Treat it as a failed Anthropic API workflow until the root cause is understood.

Is this guaranteed to have one fix?

No. The imported evidence supports the troubleshooting path above, but tool behavior can vary by account, plan, version, provider, and local configuration.

How do I know the fix worked?

Rerun the same command, editor action, or request. The fix is working when that action completes without APIStatusError: Status code 200 (expected 529) — mid-stream 'overloaded_error' event not properly mapped in streaming response.