@subscriptonarc/sdk

Typed SubScript API client for Arc USDC payments — payment intents, subscriptions, metered usage, and webhook verification. Zero runtime dependencies (uses native fetch and node:crypto).

npm install @subscriptonarc/sdk

Quick start

import { SubScript, usdc } from "@subscriptonarc/sdk";

const subscript = new SubScript({ secretKey: process.env.SUBSCRIPT_SECRET_KEY! });

// One-time payment
const intent = await subscript.intents.create({
  title: "Order #1042",
  amountUsdcMicros: usdc(15),            // 15 USDC -> "15000000"
  successUrl: "https://example.com/thanks",
});
console.log(intent.checkoutUrl);

// Subscription
const sub = await subscript.subscriptions.create({
  amountUsdcMicros: usdc(9.99),
  interval: "monthly",
});

// Metered usage
await subscript.usage.report({ userAddress: "0x…", amountUsdcMicros: usdc(0.5) });

// Check status
const status = await subscript.intents.retrieve(intent.id);

Webhooks

import { SubScript } from "@subscriptonarc/sdk";

const subscript = new SubScript({ secretKey: process.env.SUBSCRIPT_SECRET_KEY! });

// In your webhook route (rawBody is the unparsed request body string):
const signature = request.headers.get("x-subscript-signature") ?? "";
const event = subscript.webhooks.constructEvent(
  rawBody,
  signature,
  process.env.SUBSCRIPT_WEBHOOK_SECRET!,
);
// throws if the signature is invalid; otherwise returns the parsed event
switch (event.type) {
  case "payment.succeeded": /* … */ break;
  case "subscription.renewed": /* … */ break;
  case "subscription.payment_failed": /* dunning */ break;
  case "subscription.canceled": /* … */ break;
}

API

• subscript.intents.create(params) / .retrieve(id)
• subscript.subscriptions.create(params) / .retrieve(id) / .list({ subscriber }) / .cancel(id)
• subscript.usage.report({ userAddress, amountUsdcMicros })
• subscript.webhooks.verify(rawBody, sigHeader, secret) / .constructEvent(...)
• Helpers: usdc(decimal) → micro-USDC string, fromMicros(micros) → decimal string

All amounts are integer micro-USDC (1 USDC = 1,000,000). The full contract is published as an OpenAPI 3.1 spec.

Non-2xx responses throw SubScriptError (.status, .body).