Adyen HTTP errors -> the unified taxonomy. 401/403 (bad key) and 422
(validation) are caller-side invalid_request, 429 is rate_limited and 5xx is
psp_unavailable — both retryable. A 409 is replayable only when Adyen marks it
transient, and errorCode 704 (a duplicate racing the in-flight original)
resolves itself moments later.
Adyen HTTP errors -> the unified taxonomy. 401/403 (bad key) and 422 (validation) are caller-side invalid_request, 429 is rate_limited and 5xx is psp_unavailable — both retryable. A 409 is replayable only when Adyen marks it transient, and errorCode 704 (a duplicate racing the in-flight original) resolves itself moments later.