Include copyable upstream status and error bodies in provider SSE failures for OpenAI-compatible and native Anthropic transports, while preserving retry behavior and safe logging defaults.
Generalize retryable_upstream_status to HTTP 500-599 plus 429.
Improve execute_with_retry log label with actual status.
Preserve OpenAI InternalServerError 5xx in map_error after overload check.
Unify native stream send: log via _raise_for_status then optional async aclose.
Add _maybe_await_aclose for httpx doubles in tests.
Rename openai compat retry tests to 5xx; parameterize native/limiter/mapping tests.
Extend execute_with_retry with retryable_upstream_status for 429/503
shared backoff, reactive block, and TRACE provider.retry.scheduled.
Map InternalServerError(503) to APIError with preserved status.
Native transport closes-and-raises on 503 like 429 for clean retries.
Add NIM/OpenAI-compat and rate limiter tests.
Consolidates the incremental refactor work into a single change set: modular web tools (api/web_tools), native Anthropic request building and SSE block policy, OpenAI conversion and error handling, provider transports and rate limiting, messaging handler and tree queue, safe logging, smoke tests, and broad test coverage.
Alishahryar1