@resvary/sdk

Open-source prepaid credits and usage billing for AI products.

Primary imports:

import { CreditLedger } from '@resvary/sdk/credits';
import { createMeterDefinition, createPriceVersion, rateUsage } from '@resvary/sdk/pricing';
import { ArcCreditFunding } from '@resvary/sdk/funding/arc';

The SDK provides USD credit accounts, linear, graduated, and package pricing, manual grants, recurring allowance policies, expiring promotions, deterministic credit lots, reserve/commit/release, immutable usage receipts, idempotency, a transactional outbox, and signed credit webhooks. It has no database or AI provider dependency. Policy commands require the optional CreditPolicyStore capability; existing custom CreditStore implementations retain their previous flows.

Advanced price versions use components: graduated tiers charge each cumulative range independently, while package pricing charges every started block. Existing rates and linear receipt line items remain unchanged. See docs/usage-rating.md in the repository.

Legacy stablecoin payment imports remain under /receipts, /middleware, /client, and /gateway. Legacy paywall middleware requires a trusted verifyPayment callback and fails closed without one. BuyerClient also fails closed on 402 unless the caller configures per-request and total spend limits plus a recipient allowlist. UsageMeter and createBillingPlan are deprecated for new balance systems.

See the repository README and docs/ for the complete quickstart and security model.