What changed
OpenAI Node SDK 7.50 adds 12-hour Responses caching, cache-write usage and project service-tier settings; 7.51 adds Australia, India and Japan residency options, GPT-6 Rosalind catalog types, image-complexity and GIF/SVG controls, and broader agent-turn, image and audio fields. These are signed client types, not proof that every service field is enabled for every account.
Why it matters
Caching, residency and service tiers affect cost and data-location policy, while new media and agent error variants change exhaustive handling. The typed surface is useful only if account-level behavior, cache billing and regional routing match the generated contract.
What to do
Pin 7.51 in a branch, compile exhaustive unions, replay cache hits and writes, request a permitted residency option and exercise GIF, SVG, audio and agent-error paths in a non-production project; reconcile returned usage and routing evidence before promotion.
Caveat
The immutable signed SDK releases establish generated types and package identity, not independent availability, residency, pricing or model-quality evidence. GPT-6 Rosalind appearing in the catalog does not by itself establish general model access.