Function status_error 

pub fn status_error(status: u16, headers: &HeaderMap, body: &str) -> LlmError

The one error table of all providers (design page): 401/403 are an authentication error, 402 and a billing-quota 429 a quota error (no retry), other 429s are rate limits with their retry-after, 5xx (also 529) an overloaded service, a context-length rejection its own error, everything else a rejected request.