Hyperswitch is a composable open-source payments infrastructure built in Rust that provides a modular platform for processing payments through multiple connectors. The system handles the complete payment lifecycle including authorization, capture, refunds, and dispute management, while offering features like intelligent routing, 3DS authentication, revenue recovery, and analytics. Built with a microservices architecture using Actix-web, it features a plugin-based connector system, event-driven design with Redis/Kafka, and comprehensive SDK support for web and mobile platforms. The codebase demonstrates strong engineering practices with typesafe ID generation, robust encryption utilities, and well-abstracted interfaces that promote reusability and maintainability.
Payum is a framework-agnostic PHP payment processing library that unifies dozens of payment providers (PayPal, Stripe, Klarna, Authorize.Net, Be2Bill, Payex, Sofort, Offline, and others) behind a common API. The code reveals a dual architecture in transition: the mature 1.x action/request/reply model coexists with a newer 2.x command/handler/context model that returns typed result objects and executes through a middleware pipeline. Core capabilities include gateway factories, registry and container abstractions, token-based security URLs, pluggable storage backends (Doctrine ORM, MongoDB ODM, filesystem, Laminas), Twig template rendering, PSR-7/14/18 support, event dispatching, and currency/money handling. It is a library meant to be embedded inside Symfony, Laravel, or plain PHP applications, not a standalone service. The architecture is genuinely well-engineered: the middleware pipeline, handler map, token factory, and storage abstractions are cleanly separated and heavily unit-tested. However, the codebase is mid-migration between 1.x and 2.x APIs, with many deprecated legacy adapters and bridge classes still present. This dual-path design increases complexity and can confuse new users, but the core abstractions remain sound and reusable. The repository is a monorepo with per-gateway subpackages, extensive PHPUnit coverage, CI workflows, static analysis, and release automation. Technical drift is moderate: gateway integrations using old SOAP/XML-RPC SDKs and deprecated Symfony/Httplug bridges are aging, while the core 2.x architecture is actively maintained.
This repository is the official Mollie API client for Node.js (TypeScript), providing a typed SDK for integrating with the Mollie payment platform. It exposes a factory function `createMollieClient()` that returns an object with resource binders (e.g., `payments`, `orders`, `customers`, `refunds`, `settlements`), each offering CRUD operations and additional actions like cancellation or refunding. The architecture follows a clean layered design: resource-specific binders delegate to a shared `TransformingNetworkClient` that handles HTTP requests, response transformation, pagination, idempotency keys, retries, and throttling. Data models are separated into raw API interfaces and sealed helper-enriched types, with embedded/linked resource access abstracted through helper classes. The SDK supports both API key and OAuth authentication, callback-style and Promise-based APIs, and includes extensive test suites (unit, integration, and cross-runtime compatibility for Node, Bun, and Deno). The codebase is well-structured, uses modern TypeScript features, and includes a custom iteration API for paginated resources. Notable internal patterns include a generic Binder base class, parameter default injection, a throttling utility, and a rich set of type utilities (Maybe, Nullable, Seal, Xor).
svelte-stripe is a Svelte component library that wraps Stripe Elements and Stripe.js, providing drop-in Svelte components for building payment UIs. It exposes context-based components such as Elements, PaymentElement, CardNumber, CardExpiry, and CardCvc, and handles Stripe.js loading, element lifecycle, and SSR safety. The repository also includes a SvelteKit demo application with examples for credit card, SEPA, iDEAL, and express checkout, plus server-side payment intent creation and webhook signature verification. It is a library and example app, not a data pipeline.
This repository is a React Native library that integrates Paystack payment processing into mobile applications using a WebView-based modal. It provides a `PaystackProvider` component that wraps the app and exposes a `usePaystack` hook for initiating transactions. The library handles parameter validation, generates an inline Paystack checkout page, and communicates payment events back to the app via WebView postMessage. It also supports deep linking for payment channels like Zap, intercepting specific URLs and opening them via the OS. The architecture follows a Provider pattern with context, making the payment functionality accessible throughout the app. The code is written in TypeScript with full type definitions and includes a test suite using Jest. However, the package.json contains unrealistic dependency versions (e.g., react@^17.0.1) indicating potential maintenance issues. The core utility functions for URL routing and external URL opening are well-designed and could be reused in other projects.