Mission Control · API bay · §4.1

Prompt Caching Optimizer

Paste a prompt and we'll auto-segment it, classify each section stable / volatile, suggest the optimal cache_control breakpoint placement, and show the monthly savings across Anthropic, OpenAI, and Gemini.

1. Paste your prompt

User: I want to ship a Stripe checkout flow today.

<context>
Stripe accepts payments via Checkout Sessions, Payment Intents, or Subscriptions. For one-time payments under $5k, Checkout Sessions are the simplest path. For metered billing or seat-based subscriptions, you'll need a Subscription with Prices objects. Webhook verification requires the raw request body — never use a body parser before signature verification. The webhook secret rotates per environment; production has a different whsec_ value than test. Idempotency keys prevent double-charges on retried requests. Tax calculation requires Stripe Tax to be enabled. PCI compliance is met automatically when using Stripe.js or Checkout — never accept raw card details on your server.
</context>

<examples>
Example 1: Create a Checkout Session for a $20 product. Use mode='payment', line_items with a single Price, and success_url + cancel_url. The session.id goes into stripe.redirectToCheckout() on the client.
Example 2: Listen for checkout.session.completed in the webhook, then fulfill the order. Verify the webhook signature using stripe.webhooks.constructEvent().
</examples>

2. Workload

Model

Calls per day

Force volatile (label list)

Comma-separated labels to force-mark as volatile (case-insensitive).

3. Verdict

$8.67/mosaved with cache_control on Sonnet 4.6

Total tokens

226

Cacheable prefix

214

Saved per call

$0.0006

Reorder needed?

YES

›Prompt is 226 tokens — below Anthropic's ~1024-token minimum for cache_control. Add stable reference material or skip caching.
›Reorder would lift cacheable prefix from 0 → 214 tokens.

4. Detected segments (reordered)

STABLEcontext
705 chars
STABLEexamples
386 chars
↓ cache_control: { type: "ephemeral" } — Stable prefix is only 214 tokens — under Anthropic's ~1024-token cache minimum. Expand stable content or skip caching.
VOLATILEUser: I want to ship a Stripe checkout f
50 chars

5. Savings across providers

Provider · Model	Input $/M	Cache $/M	Saved/mo
Haiku 4.5	$1.00	$0.10	$2.89
Sonnet 4.6← pick	$3.00	$0.30	$8.67
Opus 4.7	$15.00	$1.50	$43.34
GPT-4o	$2.50	$1.25	$4.01
Gemini 2.5 Pro	$1.25	$0.31	$3.02

6. Reordered prompt (copy this)

<context>
Stripe accepts payments via Checkout Sessions, Payment Intents, or Subscriptions. For one-time payments under $5k, Checkout Sessions are the simplest path. For metered billing or seat-based subscriptions, you'll need a Subscription with Prices objects. Webhook verification requires the raw request body — never use a body parser before signature verification. The webhook secret rotates per environment; production has a different whsec_ value than test. Idempotency keys prevent double-charges on retried requests. Tax calculation requires Stripe Tax to be enabled. PCI compliance is met automatically when using Stripe.js or Checkout — never accept raw card details on your server.
</context>

<examples>
Example 1: Create a Checkout Session for a $20 product. Use mode='payment', line_items with a single Price, and success_url + cancel_url. The session.id goes into stripe.redirectToCheckout() on the client.
Example 2: Listen for checkout.session.completed in the webhook, then fulfill the order. Verify the webhook signature using stripe.webhooks.constructEvent().
</examples>

User: I want to ship a Stripe checkout flow today.

How the optimizer thinks

Cache works on prefixes, not on chunks. If a single volatile block sits before your stable reference docs, NONE of those docs are cacheable. Stable-first ordering is the whole game.

Auto-segmentation honors structure. The optimizer prefers XML tags (<context>, <example>), markdown headings, and role markers (User:, Context:) as section boundaries.

Anthropic minimum is ~1k–2k tokens. Cache_control on a short prompt is a no-op. The optimizer flags this — don't pay for the cache-write overhead if you're under the floor.

Up to 4 breakpoints. Anthropic accepts 4 cache_control breakpoints per request. The optimizer suggests the primary one (after the last stable block) plus secondaries when stable content is unusually large.