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Code Examples

The following open-source repositories demonstrate end-to-end integrations with the Strictly payment API. They range from a minimal single-file quickstart to a full Angular + NestJS application.

All repositories use the same core integration pattern:

1. Collect card data client-side using ZeroGateway.js
2. Send the paymentToken to a backend server
3. Make the charge or vault request from the server using your API credentials

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Choose your starting point

Repository	Stack	Best for
ecommerce-integration-js-simple	Plain HTML	Quickest possible integration
ecommerce-integration-js-advanced	HTML + Vanilla JS	Styling and CSS customization
multi-step-payment-integration	Node.js / Express	Realistic checkout UX
ecommerce-integration-api	NestJS	Backend-only / API layer
ecommerce-integration-angular	Angular + NestJS	Full-stack production reference

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ecommerce-integration-js-simple

Repository: github.com/strictlyzero/ecommerce-integration-js-simple

The fastest way to see a working integration. A single index.html file that loads ZeroGateway.js, collects card data, and submits a charge — no build tools or server framework required.

Stack: Pure HTML5 (no dependencies)

Use this if:

• You want to understand the basic flow before building a real integration
• You're embedding a payment form in a simple web page

Run it:

Code
# Serve with any static file server
npx http-server .
# or
python -m http.server

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ecommerce-integration-js-advanced

Repository: github.com/strictlyzero/ecommerce-integration-js-advanced

Extends the simple example with custom styling, focus/valid/invalid state CSS, and a whitelist of 80+ allowed CSS properties for secure iframe field customization.

Stack: HTML5 + Vanilla JavaScript

Use this if:

• You need to match the payment form to your brand
• You want to see how ZeroGateway.js customCss, validCss, and invalidCss options work

Run it:

Code
npm install
node main.js

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multi-step-payment-integration

Repository: github.com/strictlyzero/multi-step-payment-integration

A multi-step checkout flow with a Node.js/Express backend. Demonstrates the complete client → tokenize → server → charge pipeline in a realistic UX pattern, with separate steps for contact info, card entry, and confirmation.

Stack: Node.js / Express (backend) + HTML + Vanilla JS (frontend)

Use this if:

• You're building a standard e-commerce checkout
• You want a reference for the server-side charge request and response handling

Run it:

Code
git clone https://github.com/strictlyzero/multi-step-payment-integration.git
cd multi-step-payment-integration
npm install
node app.js
# Open http://localhost:3000

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ecommerce-integration-api

Repository: github.com/strictlyzero/ecommerce-integration-api

A NestJS service that acts as the backend API layer for the Angular frontend example below. Useful as a reference for structuring server-side payment logic in a typed TypeScript/NestJS codebase.

Stack: NestJS (TypeScript)

Use this if:

• You're building on NestJS and want a reference for service/module structure
• You want to run the Angular + NestJS full-stack example

Run it:

Code
git clone https://github.com/strictlyzero/ecommerce-integration-api.git
cd ecommerce-integration-api
npm install
nest start
# API runs on http://localhost:3000

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ecommerce-integration-angular

Repository: github.com/strictlyzero/ecommerce-integration-angular

A full-stack reference with an Angular frontend and the NestJS API above as its backend. The most complete example — shows component structure, service layers, TypeScript types, and end-to-end payment flow.

Stack: Angular (TypeScript) + NestJS backend

Use this if:

• You're building an Angular application
• You want the most production-like reference for architecture

Run it:

Code
# Start the backend first (see ecommerce-integration-api above)

# Then start the frontend
git clone https://github.com/strictlyzero/ecommerce-integration-angular.git
cd ecommerce-integration-angular
npm install
ng serve
# Open http://localhost:4200

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Common patterns across all examples

All examples follow the same fundamental security pattern:

Code
[Browser]                    [Your Server]               [Strictly API]
    │                              │                            │
    │  1. Load ZeroGateway.js      │                            │
    │  2. Customer enters card     │                            │
    │  3. Collect paymentToken ────────────────────────────────►│
    │◄─────────────────────────────────────────── token ────────│
    │  4. POST token to server ───►│                            │
    │                              │  5. POST /payment/charge ──►│
    │                              │◄───────────── response ────│
    │◄──────────── result ─────────│                            │

Your API credentials (key-hash, Authorization) are only ever used in step 5 — on your server. They never touch the browser.

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Next steps

• Tokenization — understand how ZeroGateway.js works before running the examples
• Best Practices — common mistakes to avoid when adapting the examples for production
• API Reference — full endpoint documentation