AI caching reuses previous work instead of repeating all computation for every request. An application response cache stores completed answers, while a provider-managed prompt-prefix cache may reuse processing of shared input. Their behavior and billing depend on the specific implementation.
Exact and semantic response caches
An exact cache requires the relevant request fields to match. A semantic cache searches for a similar request and decides whether a stored answer is appropriate. Similar wording does not establish equivalent permissions, intent, or facts.
Design the cache key
Include the model and prompt version, policy or document version, locale, and authorization scope when they affect the answer. An identical question from two users can require different answers. Never share a cached private response across tenants.
Example: changing stock availability
A cached product description may remain useful longer than a stock quantity or price. Separate stable explanatory content from live transactional facts, set a suitable expiration policy, and invalidate affected entries when the underlying record changes.
Measure the actual benefit
Track cache hit rate, incorrect reuse, stale responses, total latency, and cost per successful task. Include lookup and invalidation costs. Do not assume a universal percentage saving or treat every cache hit as a correct answer.
References and further reading
Maintained by DriftRail. AI assisted the October 2026 content and template revision. Examples are illustrative; they are not measured product benchmarks. Suggest a correction.