Next.js Weekly #119: Cloudflare Next.js Drama, Chat SDK, Sandcastle, New useActionState Docs, Query Abstractions

How we rebuilt Next.js with AI in one week

Cloudflare spent one week and $1,100 on AI tokens to build vinext, a supposed drop-in replacement for Next.js that runs on Vite and deploys to Cloudflare Workers out of the box. It's experimental, but it has been tested against the Next.js test suite.

This sparked heated discussions on X / Twitter:

• We've identified critical vulnerabilities in Vinext
• Gergely Orosz is disappointed with Cloudflare's "marketing"
• What Cloudflare's 94% test coverage for vinext actually means

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📙 Articles / Tutorials / News

Building Design Components with Action Props using Async React

If you find yourself wiring up loading states and optimistic updates every time a user interaction triggers a Server Component re-render, this post shows a cleaner way by building reusable components that handle all of that internally

Set up your Next.js project for AI coding agents

Next.js has introduced a new guide on how to make AI coding agents smarter in your project

New useActionState docs

The React team has published a major rewrite of the useActionState documentation. The new version clearly explains how action queuing works, how to use it with forms, Server Functions, and useOptimistic, and how to handle errors and cancellation. It also adds detailed troubleshooting sections and practical examples

The Journey to a Safer Frontend: Why We Removed React.FC

Gusto’s frontend team removed React.FC after learning it could hide bugs and weaken type inference

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📦 Projects / Packages / Tools

Chat SDK

Vercel released a new open source TypeScript library that helps you create chatbots for multiple platforms using a single codebase. It comes with type-safe events, JSX-based UI components, Redis state adapters, and built-in AI streaming support

styled-components@6.3.0

After going into maintenance mode last year, the library returns with React Server Components support. No use client directive is needed, and CSS is automatically injected and handled correctly in React 19. Existing SSR setups still work as before

next-bun-compile

A new build adapter for Next.js 16 that turns your app into a single executable file using Bun. It embeds your static assets, public files, and Next.js server into one binary

Sandcastle

An experimental project powered by Vercel and Vercel Sandbox. Each user gets isolated Linux workspaces accessible from any browser, with a window manager, terminal, file browser, code editor, and X11 app streaming

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🌈 Related

We Ralph Wiggumed WebStreams to make them 10x faster

Vercel found that WebStreams were slowing down Next.js rendering due to excessive Promise and allocation overhead. They built fast-webstreams, a drop-in, spec-compliant replacement powered by Node.js streams internally, achieving up to 14x faster performance for the React Server Components streaming pattern

Private storage for Vercel Blob, now available in public beta

Vercel Blob now offers private storage for sensitive files. Unlike public storage, all reads and writes require authentication, so files aren’t exposed via public URLs

Creating Query Abstractions

This article looks at different ways to share query configuration in TanStack Query. It explains why custom hooks can be limiting and introduces queryOptions as a better abstraction that works across hooks, Suspense, and server usage

A New Home for React Hosted by the Linux Foundation

React is now officially owned by the newly launched React Foundation, hosted by the Linux Foundation. This means React, React Native, and JSX are no longer owned by Meta, but by an independent foundation instead. The goal is to support React’s long-term future with open governance and shared ownership across the ecosystem