Payments GitHub Repositories (2026) · Open Source Tools

Adyen API Library for PHP

Braintree Java library

💳✨ Add usage-based credits to your Rails app

Adyen Payment plugin for Magento2

Non-custodial Stellar/USDC payments API for DeenBridge — SEP-1/7/10/29, path payments, multi-asset trustlines, and Horizon reconciliation on a Node/Express + MongoDB core.

Tom microservice toolkit for Stripe customers, subscription plans, email, and notifications.

Adyen Android Drop-in and Components

Adyen API Library for Java

Braintree .NET library

PayPal payment gateway extension for WooCommerce.

Adyen API Library for .NET

SumUp Android SDK.

Offline-first Python AI agent that runs a tiny research business: quotes each job against its own costs, collects via Stripe, fulfils with NVIDIA Nemotron, pays vendors within a spend policy, and declines unprofitable work.

A sandbox for the third-party APIs you depend on. Built from the provider's spec, it fails on purpose, and it replays the exact failure production hit.

Familiar money. New markets. BUYIN financial access layer for Robinhood Chain — product documentation and an offline reference.

Refunds for AI-agent purchases, enforced on Stellar. The pact escrow contract (Soroban, Rust): the buyer's cap waits until a verifier's signed verdict decides what the seller is paid, and the rest goes back automatically. Testnet, not audited.

Kill Bill reusable Java components

An easy to use library that allows you to manage and access payment icons

Braintree Node.js library

Braintree Ruby library