A server that is not ready does not always take its time about saying so.
Ollama answers 5xx immediately while a model is still being loaded, and a
gateway with no upstream yet does the same, so the failure arrives at
once rather than as a timeout.
Both mean "not right now" and are worth one more attempt. 4xx keeps
being final -- a wrong API key or an unknown model name is not going to
change between two requests.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
jasonwitty
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