Caching LLM responses without serving the wrong answer

Choose the cache boundary

A cache key may include the normalized request, model, system policy, tenant, locale, permissions and relevant data version. Omitting a required dimension can produce a technically successful cache hit that returns the wrong user or stale policy result.

Set freshness by workload

Static explanations can tolerate longer reuse than prices, inventory, account data or live events. Define expiration and invalidation from the underlying information lifecycle rather than a single global time-to-live.

Measure quality and avoided generation

Track hit rate, latency, provider usage avoided, stale hits and incorrect reuse. Compare the cached path with normal generation on sampled traffic so cost improvements remain tied to acceptable application behavior.

Measurement checklist

1. Choose a representative completed task, not an artificial one-line prompt.
2. Record the selected model, provider input, cached input, output, retries and final result.
3. Change one optimization mechanism at a time so the cause remains visible.
4. Verify required identifiers, tool calls, code changes or business fields.
5. Keep passthrough available when the reduced request does not pass.

Varion commercial evaluation

Varion keeps proprietary product implementation details private. Evaluate Token Optimisation on representative traffic and judge it by the measured commercial result. New verified users receive 100,000 processed input tokens and 50 local test runs.