guideprompt caching guidellm cost optimizationcache hit pricingreduce ai costapi cachingPrompt Caching Guide: Cut LLM Input Costs by up to 98%How prompt caching works and how to use it to cut LLM API costs — cache-hit rates by provider (Claude, DeepSeek, Gemini, Kimi), the prefix rule, and common mistakes.2026-07-10claire-lowe
