fix(rate_limiter): retry transient non-529 5xx responses - #145
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is_retryable_error matched only the enumerated 529 (overloaded), so other transient upstream 5xx — 520/522/523/524 (Cloudflare edge errors that the Anthropic API surfaces under load) — were treated as terminal. A unit hit by a transient 520 that outlasts the SDK's own retries was finalized as ERROR instead of being retried. Treat the transient 5xx range as retryable (520/522/523/524 alongside 529) without making deterministic client 4xx errors retryable. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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July 10, 2026 18:17
gadievron
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July 10, 2026 18:17
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is_retryable_error matched only the enumerated 529 (overloaded), so other
transient upstream 5xx — 520/522/523/524 (Cloudflare edge errors that the
Anthropic API surfaces under load) — were treated as terminal. A unit hit by a
transient 520 that outlasts the SDK's own retries was finalized as ERROR
instead of being retried.
Treat the transient 5xx range as retryable (520/522/523/524 alongside 529)
without making deterministic client 4xx errors retryable.
Co-Authored-By: Claude Opus 4.8 (1M context) noreply@anthropic.com
Found by a deep reachability/call-graph validation of the parser corpus: the 2026 release fixed this bug class at some parser sites but left this sibling. Ships with a RED->GREEN regression test driving the real parser/detector pipeline (not a mock). One of a 9-PR series of independent, region-disjoint fixes; verified together (full suite green, no collisions).
🤖 Generated with Claude Code