LLM caching: three different mechanisms and when to use each

Exact response cache

Exact caching is safest when the request is deterministic, permissions are isolated and the response remains valid. Cache keys must include every input that changes behavior. Tenant isolation and expiration rules are essential.

Provider prompt cache

Prompt caching is controlled by the model provider and reported through provider usage. It can help large stable prefixes without returning an old answer. Eligibility and pricing vary by model.

Semantic cache

Semantic caching can save the full model call, but similarity is not equivalence. It needs strict thresholds, domain checks and a strategy for rapidly changing data. Varion currently emphasizes exact cache and measured context reduction rather than presenting semantic similarity as guaranteed correctness.

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.

Official provider reference

Check the current documentation for pricing and usage rules.