// the problem

Seat-based billing can't price a robot.

Your product does work on a user's behalf — a generation, a run, a tool call. Per-seat plans don't map to that, and rolling your own credit system means reconciling balances, races on concurrent spend, and a metering pipeline you'll babysit forever.

races

Two requests spend the last credit at once. Now you're negative.

drift

Stripe says one thing, your DB says another. Support tickets pile up.

refunds

A job fails mid-run. Crediting back the unused portion is all manual.

rebuilds

Every pricing change is an engineering project instead of a config edit.

// the primitives

Four primitives. Everything you'd otherwise build by hand.

credits.grant()

Credits

An append-only balance per user. Grant, spend, top up — every change is an immutable ledger entry you can audit.

reservations.create()

Reservations

Hold credits before a job runs, then commit the real cost or release the rest. No races, no negative balances.

meter.record()

Metering

Record usage events and roll them into credits with rules you change in config — not in a deploy.

can()

Entitlements

Sub-millisecond 'is this allowed?' checks at the edge of every request, driven by plan and balance.

// agent-native docs

Your docs are written for the thing that writes your code.

Every page has a .md twin and we publish llms.txt. Point Cursor or Claude Code at a URL and it pulls the exact, current integration straight into your repo — no copy-paste, no stale snippets.

✓Append .md to any docs URL for raw markdown
✓Official entity page at /ai-info (markdown: /ai-info.md)
✓One-click "Copy for AI" on every page
✓Versioned, so the agent never sees a deprecated call

cursor — agent

▸ add quotastack credits to my checkout route

⠿ fetching quotastack.io/docs/reservations.md …

1 const r = await qs.reservations.create({

2 user: userId, amount: estCredits,

3 operation: "image.generate"

4 });

5 // …on success

6 await r.commit(actualCredits);

✓ applied · matches your live API version v1

// pricing that's actually fair

Free until you're billing real money.

No credit card to start. No monthly minimum. No plan to pick. Pay only for the metered events you send — entitlement checks, balance reads, and idempotent retries are never counted. Sandbox is always free.

Start free → See full pricing

First ~100k events / mo $0 $2 usage credit

Then, pay as you go $2 / 100k events

Sandbox + checks + retries free never counted

Credit-native billing.
Agent-native docs.