Anthropic API / Anthropic API
Anthropic Bedrock SSE Error Events Not Handled Properly in SDK
Fix Anthropic SDK for Bedrock so error SSE events (rate_limit_error, model_not_found) are properly decoded as error events rather than being misclassified as completion events Includes evidence for Anthropic API troubleshooting demand.
- Category
- Anthropic API
- Error signature
AWSEventStreamDecoder emits every decoded frame as ServerSentEvent(event=completion) even for Bedrock error payloads like rate_limit_error and model-not-found, causing client code to process error events as completions- Quick fix
- Reduce request pressure, check quota or plan limits, and retry with backoff instead of immediate repeated requests.
- Updated
What this error means
AWSEventStreamDecoder emits every decoded frame as ServerSentEvent(event=completion) even for Bedrock error payloads like rate_limit_error and model-not-found, causing client code to process error events as completions is a Anthropic API failure pattern reported for developers trying to fix anthropic sdk for bedrock so error sse events (rate_limit_error, model_not_found) are properly decoded as error events rather than being misclassified as completion events. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.
Why this happens
GitHub anthropics/anthropic-sdk-python PR #1572 (open since 2026-05-19). AWS Bedrock delivers error payloads over HTTP 200 event stream with type=error, but the decoder strips the event type header. This means rate limiting and model-not-found errors are processed as successful completions. Category: Anthropic API (Bedrock integration with pay-per-token model).
Common causes
- GitHub anthropics/anthropic-sdk-python PR #1572 (open since 2026-05-19). AWS Bedrock delivers error payloads over HTTP 200 event stream with type=error, but the decoder strips the event type header. This means rate limiting and model-not-found errors are processed as successful completions. Category: Anthropic API (Bedrock integration with pay-per-token model).
Quick fixes
- Confirm the exact error signature matches
AWSEventStreamDecoder emits every decoded frame as ServerSentEvent(event=completion) even for Bedrock error payloads like rate_limit_error and model-not-found, causing client code to process error events as completions. - Check the Anthropic API account, local tool state, and provider configuration involved in the failing workflow.
- 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
- Capture the exact error message and the command, editor action, or request that triggered it.
- Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
- Review the source evidence below and compare it with your environment.
- Apply one change at a time and rerun the smallest failing action.
- 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
Evidence note: GitHub anthropics/anthropic-sdk-python PR #1572 (open since 2026-05-19). AWS Bedrock delivers error payloads over HTTP 200 event stream with type=error, but the decoder strips the event type header. This means rate limiting and model-not-found errors are processed as successful completions. Category: Anthropic API (Bedrock integration with pay-per-token model).
Related errors
- Anthropic API
FAQ
What should I check first?
Start with the exact AWSEventStreamDecoder emits every decoded frame as ServerSentEvent(event=completion) even for Bedrock error payloads like rate_limit_error and model-not-found, causing client code to process error events as completions 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 AWSEventStreamDecoder emits every decoded frame as ServerSentEvent(event=completion) even for Bedrock error payloads like rate_limit_error and model-not-found, causing client code to process error events as completions.