Merge vs Payroll Engine

Merge has no write-up on Specifiction yet; its figures are above.

Payroll Engine is an open-source framework for embedding payroll processing into larger software platforms. Released under the MIT License, it provides a backend that processes payroll data through a REST API and configurable regulation layers; country regulations are commercial. It supports time-stamped payroll data, recurring and non-recurring payruns, and reports for payslips, legal filings, or data exchange. Its API covers tenant and employee management, payrun jobs, result queries, report output, and backend event webhooks. A browser application manages tenants, employees, regulations, case data, payruns, reports, tasks, and developer logs. The .NET Client SDK includes typed REST clients, test runners, local script tools, and JSON schemas for regulation validation. A built-in test framework supports case validation, payrun assertions, and regression testing. The backend is designed for local or Docker Compose deployment, and a database must be provided separately. API key and OAuth authentication are supported but disabled by default; audit trails are also disabled by default unless configured. The maker says the backend is a service and should not be used on the public Internet.