Surfil
// savings estimator

Know what caching really costs you.

Most tools assert an ROI you cannot check. This asserts nothing: it applies published provider cache multipliers to your own numbers, so you see where your input cost sits and what raising reuse is worth.

surfil · credits - this cycle
Credit balance5,040 total
window 240monthly 1,500paid 3,200granted 100
−1signed savings receiptmonthly
+3200top-up packpaid
−2Pilot query ×2paid
Try it

Your cache position

Enter your monthly context tokens and how often a cached prefix is reused. Every figure below comes from published provider multipliers, not from us.

Effective cost per context token0.28x
Your input cost, in token-equivalents1,392,857
Same context with no caching at all5,000,000
Headroom if reuse reached 15x476,190 fewer
This is your provider's own cost model, not a Surfil claim: a cached prefix is written at 1.25x the base input rate and read back at 0.1x, so a written token only pays for itself once it has been read enough times. Reuse below about 1.4x costs more than not caching. We publish no fixed savings percentage. Surfil measures where you actually sit and stays byte-exact so your cache keeps hitting.
The model

What Surfil actually does about cost

Three things, each of them real today. None of them is a savings percentage we cannot back.

Protect the cache

Interception is byte-exact, so the prefix your provider caches still hashes the same and keeps hitting. This is the largest cost lever and Surfil never trades it away.

Prune only when it is safe

Cap rewrites redundant context ONLY on requests that declare no cache breakpoint. Rewriting a cached prefix would bust it and cost more than it saves, so Surfil refuses.

Measure, then sign

What you actually spent is measured on your own traffic and signed into a receipt you can verify offline. No percentage is asserted.

Stop estimating. Start measuring.

Install Surfil, keep working for a week, and Cap signs a receipt of what your agents actually cost - a measured number you can hand to finance and they can verify offline.