OpenAI has launched an improved prompt caching system for the GPT-6 family that delivers higher cache hit rates by default and offers discounts of up to 90% on cached input tokens. The update introduces new tools to help developers monitor performance, diagnose misses, and optimize their integrations.
- Cache discounts are now applied for eligible shared prefixes reused within a 30-minute window.
- The Prompt Caching Dashboard allows tracking hit rates over time and comparing cached versus uncached tokens.
- A diagnostics tool helps identify causes of cache misses, such as changes to tools or settings.
- Explicit cache breakpoints let developers choose specific prompt prefixes to reuse.
- Reasoning effort can be adjusted between responses without breaking the cache using configuration updates.
- Prewarming capabilities allow preparing known context ahead of time to reduce latency.
These features help persistent agents run faster and cost less by maximizing the reuse of shared instructions, tool definitions, and context across API requests.