Checkout SDK - Your page. COPE payments. Seamlessly connected.

The COPE Checkout SDK is a browser SDK (a library that simplifies integrating COPE into your project) for buyer checkout flows. It gives you control over the product page and shopping experience, while COPE handles payment collection, tax calculation, and order creation.

Use the SDK when your site owns the product and shopping experience - and COPE owns the rest.

📄 Full documentation: [Checkout SDK overview - COPE]

Installation

bash

npm install @copecart/sdk

import { CopeCart } from "@copecart/sdk"  const cope = new CopeCart({   publishableKey: "cope_pk_live_...", })

Without a bundler – global build:

html

<script src="https://unpkg.com/@copecart/sdk@latest/dist/index.global.js"></script> <script>   const cope = new CopeCart.CopeCart({     publishableKey: "cope_pk_live_...",   }) </script>

The SDK requires HTTPS – except for http://localhost during development.

Configuration

Option	Required	Default	Notes
`publishableKey`	Yes	–	Starts with `cope_pk_`, safe to use in browser code
`baseUrl`	No	COPE production API	Override only when COPE support instructs you to
`checkoutBaseUrl`	No	Origin of `baseUrl`	Used to validate checkout URLs returned by the API

Typical flow

const product = await cope.getProduct("prd_...") const cart = await cope.createCart({ currency: product.currency })  await cope.addLine(cart.id, {   product_id: product.id,   plan_id: product.payment_plans[0].id,   quantity: 1, })  await cope.setBuyerIdentity(cart.id, {   email: "buyer@example.com",   tax_location: { country: "DE", postal_code: "10115" }, })  await cope.reprice(cart.id)  const checkout = await cope.checkout(cart.id, {   success_url: "https://your-site.example/thank-you",   cancel_url: "https://your-site.example/cart",   consents: [{ type: "buyer_tos" }], })  cope.redirectToCheckout(checkout)

After successful payment, COPE redirects to success_url with order_id appended:

https://your-site.example/thank-you?order_id=ord_...

Core methods

Method	Purpose
`getProduct(productId)`	Fetch product details and payment plans
`createCart(payload)`	Create a cart and store the checkout credential
`addLine(cartId, payload)`	Add a product, plan, and quantity
`setBuyerIdentity(cartId, payload)`	Set buyer location and contact data for tax and checkout
`reprice(cartId)`	Calculate taxes, discounts, and final totals
`checkout(cartId, payload)`	Create a hosted checkout session
`redirectToCheckout(checkout)`	Navigate the browser to hosted checkout
`cancelCheckout(checkoutId)`	Cancel an open checkout session

Error handling

import {   CopeApiError,   CopeCartExpiredError,   CopeNetworkError, } from "@copecart/sdk"  try {   await cope.reprice(cart.id) } catch (error) {   if (error instanceof CopeApiError) {     console.log(error.status, error.code, error.errors)   }   if (error instanceof CopeCartExpiredError) {     const replacement = await cope.createCart({ currency: "EUR" })   }   if (error instanceof CopeNetworkError) {     console.log("Retry later")   } }

Treat 4xx errors as permanent – fix the payload and retry with a new request. The SDK automatically retries selected transient network or server failures with backoff.

Use cases

Custom product page
You build the UI, COPE handles payment collection, tax calculation, and order creation. Ideal when you want full control over the buying experience without building your own payment backend.

Multi-plan products
Dynamically fetch payment plans from COPE and present them to the buyer – monthly, annual, one-time. The SDK returns all available plans directly with the product.

Payment links
Create a checkout session server-side and send the hosted_checkout_url via email, WhatsApp, or CRM – no custom checkout UI needed.

Fast go-live
Quick integration without a custom payment backend. COPE handles PCI compliance, tax logic, and the entire payment flow.