How to cut your Claude API bill — the 5 real levers

1. Route easy requests to a cheaper model biggest lever for mixed traffic

Most teams send everything to the flagship (Opus/Fable) out of caution. But a large share of real traffic — classification, extraction, summarization, short Q&A, simple drafting — is handled just as well by Haiku (≈80% cheaper than Opus) or Sonnet (≈40% cheaper). Route per request to the cheapest model that's good enough and you typically cut 20–45% of a mixed bill.

The catch: the risk is a quiet quality regression on the requests you downgrade. You need a quality floor (never downgrade the hard stuff) and ideally proof it held. That's the whole problem ModelPilot is built to solve safely.

2. Prompt caching up to ~90% on repeated context

If you re-send the same large system prompt / context across calls, Anthropic's prompt caching bills cached reads at ~10% of input price. For RAG, agents, and long system prompts this is often the single biggest win. It's free from Anthropic — you just add a cache_control breakpoint.

The catch: it's a code change most teams never get around to, and there's a small write cost on the first call. Worth doing regardless of any vendor.

3. The Batch API 50% off async work

Anything that doesn't need a real-time answer (evals, backfills, bulk processing) can go through Anthropic's Batch API at 50% off. Stacks with caching. Free from Anthropic.

The catch: only for latency-tolerant work, and it's another code path to build.

4. Pick the right default model often overlooked

Many teams defaulted to the most capable model during prototyping and never revisited it. If your workload is mostly routine, changing the default (with a fallback for hard cases) can cut a lot before any per-request routing.

5. Right-size max_tokens smaller than you think

Honest truth: lowering max_tokens usually does not cut your normal bill — Anthropic bills on the tokens actually generated, not the cap. Its real value is capping worst-case runaway generations. Don't expect routine savings here; we'd rather tell you than pad a number.