GPT-6 prompt caching gets more reliable: higher hit rates, diagnostics, up to 90% savings
rohanpaul_ai · x · 2026-09-23
OpenAI is making GPT-6 prompt caching more reliable and controllable, adding higher hit rates, diagnostics, breakpoints, prewarming, and cache-preserving reasoning changes.
- Long-running agents resend instructions, tool definitions, and earlier context across API calls; caching avoids recomputing those prefixes.
- Reuse can cut cached-input token costs by up to 90%, and a new dashboard exposes cache-hit rates plus cached vs uncached token volume.
- Author's caveat: a high cache hit rate remains partly an application-design problem — developers must still structure agents so stable instructions and tools stay reusable.
Related event: OpenAI Upgrades GPT-6 Prompt Caching, Cutting Input Tokens by Up to 90%(4 posts)→
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