How to Validate Prompt Caching Savings for AI Agents on Bedrock in Four Steps
AWS published prompt-caching patterns for OpenAI models on Amazon Bedrock on October 26, 2026. An agent can reuse an identical prefix containing system instructions, tools, content, and history so a later request processes only the new portion. Bedrock supports implicit and explicit caching, while a cache key can share a reusable starting point across sessions or helper agents. AWS says cached prefixes have a minimum 30-minute time to live that is refreshed by successful reuse. This durable guide gives teams a four-step acceptance plan for stable-prefix design, cache-hit evidence, intentional invalidation after tool changes, latency measurement, and complete request cost instead of assuming every cache hit saves money.

