JSNation US 2025

Model Context Protocol (MCP) introduces a structured approach to LLM context management that addresses limitations in traditional prompting methods. In this workshop, you'll learn about the Model Context Protocol, its architecture, and how to build and use and MCP with Node.jsTable of Contents:What Is the Model Context Protocol?Types of MCPs (Stdio, SSE, HTTP Streaming)Understanding Tools, Resources, and PromptsBuilding an MCP with the Official TypeScript SDK in Node.jsDeploying the MCP to the Cloud (Heroku)Integrating the MCP with Your Favorite AI Tool (Claude Desktop, Cursor, Windsurf, VS Code Copilot)Security Considerations and Best Practices

Let’s demystify the secrets of modern JavaScript tooling. In this workshop, you will learn how linters, compilers, and code transforms work. You will take your first steps building your own developer tools, writing an ESLint rule, a compiler plugin, and a code transformation. Learn these skills to help your team and deepen your understanding of computer languages.Workshop Plan:A preview of how ASTs can be usedA brief walkthrough of how compilers workAn intro to working with an ASTThe secret to making thousands of changes in secondsHow to apply this skill

You probably have faced a situation where you needed to debug something particular in your application. Something in a specific condition. These kinds of situations tend to be poorly handled by us developers.A common approach is adding a bunch of logs, deploying the code, and waiting for the logs to return. This is a very slow process and can be very frustrating.It would be much better if you could just get into the environment, while running, execute some code, and see the results. This is where the node:repl module comes in. It allows you to create a Read-Eval-Print Loop (REPL) in your Node.js application.Inspired by Ruby on Rails, which has a very useful console, I implemented a console in the application I was working on. It was a game changer. Now, we have a way more effective debugging/experimentation process. My team fell in love with it. Now, it's part of the app, as it always has been.Another good thing is that it was not hard to implement. The node:repl module gives everything. We just need to ensure the application is properly bootstrapped to use the REPL module.Table of contentsThe importance of tools and DXThe module node:replHands-on: creating an iterative repl for debugging any applicationConclusionTakeawaysWhy DX matters and how to improve it through the development of custom toolsHow Node.js modules can help with the creation of effective toolsGet to know the node:repl module

In this workshop we'll dive into the latest advancements in React and best practices for building modern React apps. We'll take a look at modern NextJS and React Router 7 Framework (aka Remix) along with React's new "React Server Components". We'll also talk about improving the data-fetching strategies of your SPAs along with options for migrating your SPA to modern React Router.