概述
Eligibility, cache lifetime, pricing, and controls vary by provider and model.
深入探讨
Prompt caching reuses work for repeated prompt content, often through exact or provider-defined prefix matching. Cache behavior depends on provider, model, request structure, minimum prefix size, and retention rules. A small change near the prefix can prevent reuse. Caching may reduce repeated input processing costs, but cache writes and hits can have different prices and storage windows. It does not guarantee the model will return the same answer or make a prompt safe to store.
现实世界的实施
Reuse a stable system prompt across requests where provider rules allow.
Keep changing user-specific content after the reusable prefix.
Check provider documentation for cache-hit pricing and retention.
Avoid caching sensitive content unless the service and policy permit it.
即时缓存的未来
Providers may change cache eligibility, pricing, and lifetime. Design against current API documentation and keep sensitive-data retention requirements explicit.
付诸实践
为什么这很重要
- 成本与预算. 多年来，架构决策决定着性能和运营成本。
- 更清晰的判决. 技术教育帮助团队选择正确的堆栈，而不仅仅是最新的堆栈。
- 质量控制. 更好的工程选择可以减少生产中的可靠性事故。
留意
- 优化一项基准测试可以隐藏更广泛的系统弱点。
- 基础设施和维护成本常常被低估。
- 随着系统变得更加复杂，安全性和可观察性差距可能会扩大。
后续步骤
- 在实施之前定义延迟、质量和成本目标。
- 在实际负载和数据条件下进行基准测试。
- 仪器监控错误、漂移和用户影响。
- 在扩展之前准备回滚和事件响应路径。
不断探索
常见问题
什么是即时缓存？
Provider-managed prompt caching can reuse computation for repeated prompt prefixes. Eligibility, cache lifetime, pricing, and controls vary by provider and model.
What can a provider-managed prompt cache let a later request avoid?
The guide says providers may reuse prompt-prefix state for a matching eligible prefix, avoiding some repeated processing; implementation varies by service.
Why can a small prompt-prefix change affect cache eligibility?
The guide says cache boundaries and matching rules are provider-specific, and a small change can invalidate a cacheable prefix.
哪种场景最能从提示缓存中获益？
当在许多请求中重用一个大的、相同的块时，比如固定的系统提示或共享文档，缓存就会得到回报。
How should a team estimate the price effect of a prompt-cache hit?
Cached-token discounts and eligibility vary by provider, model, and API policy, so check the current pricing documentation.
How long does a prompt cache remain available?
Cache retention differs by provider and configuration; use the current API documentation for the chosen service.