There are only a few way to calculate prorations & manage recurring payments.

Coinbase Commerce integration client for crypto payments

Tinkoff Ruby API wrapper for payments and e2c payouts.

Ruby Client for Genesis Payment Processing Gateway

This Ruby Gem is the official reference client for the Block.io payments API. To use this, you will need the Dogecoin, Bitcoin, or Litecoin API key(s) from Block.io. Go ahead, sign up :)

Prints out a nicely formatted table of pay days for the given year(s) with the CLI command. Or returns the pay days as an array of arrays sorted by their input.

To aid Cameroon businesses to make both national and international payments using MTN and Orange Mobile Money, Paypal, Credit Card and Express Union.

Adds in-store pickup as selectable shipping and payment option during checkout.

The APIs detailed within this SDK will enable Shell's Fleet Solutions Customers to digitalize Shell Card/s and use them to pay to refuel their vehicles at Shell Stations.

A Ruby middleware implementation for the L402 protocol, leveraging macaroons and the Lightning Network for secure authentication and payments.

Calculate periodic payment given principal, rate and mortgage type

A Ruby library for integrating with PayOS payment services

Library for MVola payment provider integration

Integrate Chip-in-Asia payment gateway with Ruby on Rails applications.

Paychangu is a Ruby gem that allows you to interact with Paychangu.com's API and perform several operations like: creating payment links, creating virtual cards etc

This Spree Commerce extension integrates Cambodian payment gateways, supporting ABA Bank, Acleda Bank, and Wing for secure and seamless transactions.

This is an unofficial rest client gem for the Authroize payment gateway service. The official version does not allow for submission of extra info like billing and shipping information and customer meta data like their email. Maybe the offical gem could be hacked but we opted instead to make this ...

Uses blockchain.info's json API to generate 'checkout wallets' that can be associated with sales or customers. Your are notified when payments are made in multiple ways.

Bitsy Client gem used to create and query payment depots

This Ruby Gem is the official reference client for the Block.io payments API. To use this, you will need the Dogecoin, Bitcoin, or Litecoin API key(s) from Block.io. Go ahead, sign up :)