TypeScript SDK

Install and initialize

npm install @beinfi/sdk

import { Infi } from "@beinfi/sdk";
 
const infi = new Infi({
  secretKey: process.env.INFI_SECRET_KEY!
});

The key selects the environment. Keep it server-side. Your application's authentication remains yours; pass your own user identifiers when creating customers.

This is Infi's native SDK. The Stripe-compatible SDK is in Early access and is not a claim that this package is a drop-in replacement for every Stripe API.

Payment links

For a product with a published version:

const { url } = await infi.links.create(productId, {
  slug: "acme"
});
 
const links = await infi.links.list(productId, { slug: "acme" });

The hosted checkout handles the payment interface. The route is selected when the customer pays. See the quickstart for setup.

Checkout for a known customer

Use a stable key for the purchase intent, such as an order ID:

const { invoiceId, url } = await infi.checkout({
  slug: "acme",
  productId,
  customer: {
    externalId: user.id,
    email: user.email
  },
  idempotencyKey: order.id
});

Pix and boleto providers may require the customer's tax ID. Pass taxId in customer when required. Never send raw card details to the Infi API.

Inspect a payment

const payments = await infi.payments.listForInvoice(invoiceId);
const payment = await infi.payments.get(paymentId);
const deliveries = await infi.webhooks.listDeliveries();

Payment attempts expose their provider and outcome. Webhook delivery records help you inspect delivery; these calls do not expose a full routing-rule trace.

Idempotency

The SDK generates an idempotency key per mutating call. That protects transport retries of the same call, not a second invocation caused by a double-click.

Pass the same explicit key for the same purchase intent. Reusing a key with a different request body returns 409 idempotency_key_reused.

Resource methods take the key as a trailing argument. Shortcuts such as checkout accept idempotencyKey in the options object.

Record usage

First configure a product, a published version and the named meter. Enroll your customer in that product:

const enrollment = await infi.products.enroll(productId, {
  externalId: user.id,
  email: user.email
});
 
await infi.track({
  customerId: enrollment.id,
  productId,
  meter: "tokens",
  value: "1200",
  eventId: usageEvent.id,
  timestamp: usageEvent.timestamp
});

customerId here is the enrollment ID, not your application's user ID. Always include productId. For replayed usage, keep both eventId and timestamp stable: they participate in deduplication.

Recording usage does not by itself create a billing period or a subscription. See the company-as-code guide before enabling usage-based charging.

Receive events

Use the webhook guide to verify signatures, process events idempotently and inspect deliveries.