Hi everyone, I’m the creator of WelsonJS. WelsonJS started from a simple question: Can we build practical Windows applications using just a text editor, without relying on a heavyweight IDE? The idea was first tested in a real industrial environment in South Korea, where we needed to build a metric collection agent that could run across Windows versions ranging from Windows 2000 servers to Windows 10 PCs. What started as a practical scripting project gradually grew through real-world requirements from VPN, compliance, information security, asset valuation, live commerce, and other industries. Today, WelsonJS is an open-source JavaScript runtime for Windows automation and application development. It connects browsers, Microsoft Office, desktop applications, local files, databases, Windows APIs, and external services in a single programmable environment. More recently, we added MCP support, allowing AI clients and coding agents such as Claude, Codex, and GitHub Copilot to interact with Windows capabilities exposed by WelsonJS. The idea is simple: AI provides reasoning and planning, MCP provides the connection, and WelsonJS provides the execution layer for the Windows environment. I’d love to hear what you think about this approach. If you work with Windows automation, legacy applications, desktop software, AI agents, or MCP, I’d especially like to hear about the problems you are trying to solve. Thanks for checking out WelsonJS.

WelsonJS

Build apps with the Windows built-in JavaScript engine

Build apps with the Windows built-in JavaScript engine