Agent platforms burn budget on input tokens, and every gateway on the market breaks the provider's prompt cache, ballooning the very cost you're trying to cut.
Spend metered, cache intact. Token-efficiency and model routing built in, not bolted on.
Complexity: Provider prompt caches key on a byte-exact, order-sensitive request. Reserialize a field or reorder a header and the cache silently misses, re-billing the entire prompt. We metered, attributed, and routed every call while keeping the upstream payload byte-stable under concurrency, streaming tokens straight through without buffering, so cache hits survive the proxy hop at scale.
Approach: We modeled the cache economics first, then built a byte-stable Rust proxy on a hexagonal core, with cache integrity tracked as an invariant and gated by real end-to-end tests before anything ships.