Open-source payment libraries in 2026

Open-source payment libraries

Frameworks and platforms to build on 1

1. 1
   jPOS-EE jpos

   jPOS Extended Edition

   Framework or platform Usable You already build on jPOS and want its standard modules instead of writing your own.

   ★ 126 AGPL-3.0 Java Active, pushed 2 months ago

Building blocks for your own system 14

1. 1
   Active Merchant activemerchant

   Active Merchant is a simple payment abstraction library extracted from Shopify. The aim of the project is to feel natural to Ruby users and to abstract as many parts as possible away from the user to offer a consistent interface across all supported gateways.

   Building block Production-ready Your Ruby app needs to charge cards through one or more gateways with a single API.

   ★ 4.6k MIT Ruby Active, pushed 12 days ago
2. 2
   Payum Payum

   PHP Payment processing library. It offers everything you need to work with payments: Credit card & offsite purchasing, subscriptions, payouts etc.

   Building block Production-ready You are building a PHP shop, especially on Symfony or Sylius, and need gateway-agnostic payment flows.

   ★ 1.9k MIT PHP Active, pushed today
3. 3
   Omnipay thephpleague

   A framework agnostic, multi-gateway payment processing library for PHP 5.6+

   Building block Production-ready Your PHP app must support several payment gateways behind one interface.

   ★ 6.1k MIT PHP Slowing, pushed 4 months ago
4. 4
   Hyperswitch Prism juspay

   One library | Many payment processors | Scale to multiple processors with few lines of code.

   Building block Usable You want to support or switch between several payment processors without integrating each one separately.

   ★ 1.4k Apache-2.0 Rust Active, pushed 6 days ago
5. 5
   jPOS jpos

   jPOS Project

   Building block Production-ready You build card switching, acquiring or issuing systems in Java and need a long-established ISO 8583 toolkit.

   ★ 731 AGPL-3.0 Java Active, pushed 13 days ago
6. 6
   ACH moov-io

   ACH implements a reader, writer, and validator for Automated Clearing House (ACH) files. The HTTP server is available in a Docker image and the Go package is available.

   Building block Production-ready You build software that creates or processes US ACH files.

   ★ 570 Apache-2.0 Go Active, pushed today
7. 7
   Iso8583 moov-io

   A golang implementation to marshal and unmarshal iso8583 message.

   Building block Production-ready You build card processing or issuer services in Go and need to read or write ISO 8583 messages.

   ★ 536 Apache-2.0 Go Active, pushed today
8. 8
   JReactive-8583 kpavlov

   Kotlin/Java Client & Server for ISO8583 & Netty

   Building block Usable You need an Apache-licensed ISO 8583 network connector on the JVM instead of AGPL jPOS.

   ★ 355 Apache-2.0 Kotlin Active, pushed 40 days ago
9. 9
   Card jessepollak

   :credit_card: make your credit card form better in one line of code

   Building block Usable You maintain an older site with its own card form and want nicer input formatting.

   ★ 12k MIT SCSS Quiet, pushed 3 years ago
10. 10
    ISO8583 socketQueue juks

    ISO 8583 gateway

    Building block Usable A small fintech must share a single bank ISO 8583 link between several POS or app clients.

    ★ 216 MIT JavaScript Active, pushed 33 days ago
11. 11
    ISO8583 connection moov-io

    :satellite: Go-powered ISO8583 connection handler offering advanced binary framing, message interleaving, and a robust connection pool for load distribution and seamless reconnections.

    Building block Production-ready You use moov-io/iso8583 and need dependable network connections to card networks or processors.

    ★ 121 Apache-2.0 Go Active, pushed 5 days ago
12. 12
    ISO8583-Message-Client-java imohsenb

    ISO8583 Message Packer and Unpacker with ISOClient in Java

    Building block Usable You need a small ISO 8583 client in an Android or Java app without a full framework.

    ★ 135 MIT Java Slowing, pushed 9 months ago
13. 13
    Gringotts aviabird

    A complete payment library for Elixir and Phoenix Framework

    Building block Experimental You are on Elixir and need multi-gateway card payments without writing each integration.

    ★ 503 MIT Elixir Quiet, pushed 2 years ago
14. 14
    J2Pay tranxactive

    Multi-gateway payment processing library for java

    Building block Experimental Only if you need a starting point for multi-gateway payments in Java and will maintain it yourself.

    ★ 197 MIT Java Quiet, pushed 2 years ago

Integrations 2

1. 1
   Payment shetabit

   simple laravel payment package , supports multiple drivers

   Integration Production-ready You build a Laravel app that takes payments through Iranian gateways.

   ★ 959 MIT PHP Active, pushed 35 days ago
2. 2
   Multipay shetabit

   simple PHP payment package , supports multiple drivers

   Integration Usable You take payments through Iranian gateways in a PHP app that is not Laravel.

   ★ 308 MIT PHP Active, pushed 8 days ago

Developer tools 1

1. 1
   Isosim rkbalgi

   ISO8583 Web Simulator - Built with Go!

   Developer tool Experimental You test card payment integrations and need a free ISO 8583 simulator.

   ★ 115 Apache-2.0 Go Quiet, pushed 4 years ago

Also under payment platforms and libraries

Open-source licenses

• Permissive: 16. Use it anywhere, including in closed products. You keep the copyright notice; Apache-2.0 also grants patent rights.
• Network copyleft: 2. Like GPL, and running a changed version as a web service counts as distributing it, so its users get the source too.

Languages

PHP 4, Java 4, Go 4, Ruby 1, Rust 1, Kotlin 1, SCSS 1, JavaScript 1 and Elixir 1.