@root/paypal-checkout

In contrast to the official PayPal Checkout SDK - which is auto-generated code with lots of abstraction without much value - this is very little abstraction, but specificially designed to be (mostly) idiomatic JavaScript / Node.js.
(excuse the snake_case - that's how the PayPal REST API is designed).

The Good Documentation™ for the PayPal API (a.k.a. PayPal Checkout SDK) is the "REST API". See

• https://developer.paypal.com/docs/api/orders/v2/ (one-time payments)
• https://developer.paypal.com/docs/api/subscriptions/v1/ (recurring subscriptions)
• https://www.paypal.com/webapps/mpp/logos-buttons (the buttons)

Install

npm install --save @root/paypal-checkout

Usage

"use strict";

require("dotenv").config({ path: ".env" });

let PPC = require("@root/paypal-checkout");
PPC.init({
  client_id: "xxxx",
  client_secret: "****",
});

PPC.Subscriptions.createRequest({
  // See https://developer.paypal.com/docs/api/subscriptions/v1/#subscriptions
});

API

PayPal.init(client_id, client_secret, 'sandbox|live', defaults);
PayPal.request({ method, url, headers, json });

Subscrptions (Recurring Payments)

                                              // Webhook 'event_type':

PayPal.Product.create({ ... });               // CATALOG.PRODUCT.CREATED
PayPal.Product.list();
PayPal.Product.details(id);
PayPal.Product.update(id, { description });   // CATALOG.PRODUCT.UPDATED

PayPal.Plan.create({ ... });                  // BILLING.PLAN.CREATED
PayPal.Plan.list();
PayPal.Plan.details(id);
PayPal.Plan.update(id, { description });      // BILLING.PLAN.UPDATED

PayPal.Subscription.createRequest({ ... });   // BILLING.SUBSCRIPTION.CREATED
// subscription.links[rel="approve"].href     // BILLING.SUBSCRIPTION.ACTIVATED
                                              // PAYMENT.SALE.COMPLETED
PayPal.Subscription.details(id);
PayPal.Subscription.cancel(id, { reason });

Orders (One-Time Payments)

                                                // Webhook 'event_type':

PayPal.Order.createRequest({ purchase_units }); // CHECKOUT.ORDER.APPROVED
PayPal.Order.capture(id, { final_capture });    // PAYMENT.CAPTURE.COMPLETED

See also:

• https://developer.paypal.com/docs/api/orders/v2/#orders_create
• https://developer.paypal.com/docs/api/orders/v2/#definition-purchase_unit_request
• https://developer.paypal.com/docs/api/orders/v2/#definition-order_application_context

Redirects

• return_url
• cancel_url

return_url

Order and Subscription requests have a return return_url will be called with some or all of the following params:

# Order
https://example.com/redirects/paypal-checkout/return
  ?token=XXXXXXXXXXXXXXXXX
  &PayerID=XXXXXXXXXXXXX

• token is the Order ID
• PayerID is... exactly what it seems (no idea how you can access the Payer object though)

# Subscrption
https://example.com/redirects/paypal-checkout/return
  ?subscription_id=XXXXXXXXXXXXXX
  &ba_token=BA-00000000000000000
  &token=XXXXXXXXXXXXXXXXX

• subscription_id refers to both the Subscription ID and the billing_agreement_id of the corresponding Payments.
• ba_token (deprecated) refers to /v1/payments/billing-agreements/:ba_token
• token refers to the Order ID (perhaps created as part of the setup fee or first billing cycle payment).

cancel_url

The cancel_url will have the same query params as the return_url.

Also, PayPal presents the raw cancel_url and will NOT update the order or subscription status. It's up to you to confirm with the user and change the status to CANCELLED.

Webhooks

Webhooks can be set up in the Application section of the Dashboard:

• https://developer.paypal.com/developer/applications

You'll see a list of applications. Click on one to access the webhooks.

Security: You must put a secret or token or your webhook URLs - PayPal provides no measure of authentication (and otherwise an attacker could just send random crap to your webhooks making it look like they've paid for all sorts of things).

Security

User email addresses

Emails addresses available through the PayPal Checkout API guaranteed to have been verified by PayPal.

See:

• Is resource.subscriber.email_address verified by PayPal?
• How do I receive money through PayPal?

Notes

My discussions with Twitter Support (@paypaldev):

• https://twitter.com/search?q=(from%3Acoolaj86)%20(to%3Apaypaldev)&src=typed_query

Note: Just about everything in the PayPal SDK that uses ALL_CAPS is a constant/enum representing an option you can pick from limited number of options.

Sandbox accounts (for creating fake purchases) can be managed at: https://developer.paypal.com/developer/accounts

Auth vs Capture

Authorization and capture enables you to authorize fund availability but delay fund capture. This can be useful for merchants who have a delayed order fulfillment process. Authorize & Capture also enables merchants to change the original authorization amount in case the order changes due to shipping, taxes, or gratuity.

For any payment type, you can capture less than or the full original authorized amount. You can also capture up to 115% of or $75 USD more than the original authorized amount, whichever is less.

See

• https://developer.paypal.com/docs/admin/auth-capture/
• https://developer.paypal.com/docs/api/payments/v2/#authorizations_capture

You can auth once and capture multiple times (unless you set final_capture).

PayPal Checkout Buttons

• https://www.paypal.com/webapps/mpp/logos-buttons <== THE ONE YOU WANT
  • 
• https://developer.paypal.com/docs/checkout/
• https://www.paypal.com/buttons/

Glossary

Webhook Event: CHECKOUT.ORDER.APPROVED

{
  "id": "WH-1V203642KU442722T-3S346483MF8733038",
  "event_version": "1.0",
  "create_time": "2021-10-17T05:04:22.404Z",
  "resource_type": "checkout-order",
  "resource_version": "2.0",
  "event_type": "CHECKOUT.ORDER.APPROVED",
  "summary": "An order has been approved by buyer",
  "resource": {
    "create_time": "2021-10-17T05:03:26Z",
    "purchase_units": [
      {
        "reference_id": "{purchase-unit-id}",
        "amount": {
          "currency_code": "USD",
          "value": "10.00"
        },
        "payee": {
          "email_address": "sb-a9xvi8075587@business.example.com",
          "merchant_id": "4RXRQC77UD53U",
          "display_data": {
            "brand_name": "Bliss via The Root Group, LLC"
          }
        },
        "description": "1 year of pure Bliss",
        "custom_id": "{my-local-db-purchase-id}",
        "soft_descriptor": "Bliss"
      }
    ],
    "links": [
      {
        "href": "https://api.sandbox.paypal.com/v2/checkout/orders/4K5112848U951142F",
        "rel": "self",
        "method": "GET"
      },
      {
        "href": "https://api.sandbox.paypal.com/v2/checkout/orders/4K5112848U951142F",
        "rel": "update",
        "method": "PATCH"
      },
      {
        "href": "https://api.sandbox.paypal.com/v2/checkout/orders/4K5112848U951142F/capture",
        "rel": "capture",
        "method": "POST"
      }
    ],
    "id": "4K5112848U951142F",
    "intent": "CAPTURE",
    "payer": {
      "name": {
        "given_name": "John",
        "surname": "Doe"
      },
      "email_address": "sb-ka5d18075586@personal.example.com",
      "payer_id": "YTENGYR8PAF9A",
      "address": {
        "country_code": "US"
      }
    },
    "status": "APPROVED"
  },
  "links": [
    {
      "href": "https://api.sandbox.paypal.com/v1/notifications/webhooks-events/WH-1V203642KU442722T-3S346483MF8733038",
      "rel": "self",
      "method": "GET"
    },
    {
      "href": "https://api.sandbox.paypal.com/v1/notifications/webhooks-events/WH-1V203642KU442722T-3S346483MF8733038/resend",
      "rel": "resend",
      "method": "POST"
    }
  ]
}

Webhook Event: PAYMENT.CAPTURE.COMPLETED

{
  "id": "WH-3UT90572MR669760L-7LL94124G5389840D",
  "event_version": "1.0",
  "create_time": "2021-10-17T05:05:03.389Z",
  "resource_type": "capture",
  "resource_version": "2.0",
  "event_type": "PAYMENT.CAPTURE.COMPLETED",
  "summary": "Payment completed for $ 10.0 USD",
  "resource": {
    "amount": {
      "value": "10.00",
      "currency_code": "USD"
    },
    "seller_protection": {
      "dispute_categories": ["ITEM_NOT_RECEIVED", "UNAUTHORIZED_TRANSACTION"],
      "status": "ELIGIBLE"
    },
    "supplementary_data": {
      "related_ids": {
        "order_id": "4K5112848U951142F"
      }
    },
    "update_time": "2021-10-17T05:04:29Z",
    "create_time": "2021-10-17T05:04:29Z",
    "final_capture": true,
    "seller_receivable_breakdown": {
      "paypal_fee": {
        "value": "0.84",
        "currency_code": "USD"
      },
      "gross_amount": {
        "value": "10.00",
        "currency_code": "USD"
      },
      "net_amount": {
        "value": "9.16",
        "currency_code": "USD"
      }
    },
    "custom_id": "{my-local-db-purchase-id}",
    "links": [
      {
        "method": "GET",
        "rel": "self",
        "href": "https://api.sandbox.paypal.com/v2/payments/captures/5VK462069F664902F"
      },
      {
        "method": "POST",
        "rel": "refund",
        "href": "https://api.sandbox.paypal.com/v2/payments/captures/5VK462069F664902F/refund"
      },
      {
        "method": "GET",
        "rel": "up",
        "href": "https://api.sandbox.paypal.com/v2/checkout/orders/4K5112848U951142F"
      }
    ],
    "id": "5VK462069F664902F",
    "status": "COMPLETED"
  },
  "links": [
    {
      "href": "https://api.sandbox.paypal.com/v1/notifications/webhooks-events/WH-3UT90572MR669760L-7LL94124G5389840D",
      "rel": "self",
      "method": "GET"
    },
    {
      "href": "https://api.sandbox.paypal.com/v1/notifications/webhooks-events/WH-3UT90572MR669760L-7LL94124G5389840D/resend",
      "rel": "resend",
      "method": "POST"
    }
  ]
}