📨 #265: React Skills, json-render, ViewTransition, Base UI, shadcn, Store, Apollo, MDX, GTK | RN Windows/macOS/Harmony, Brownie, Enriched, Navigation, Teleport, Nitro | TC39, Astro, jQuery, Node.js

21 janvier 2026 · 10 minutes de lecture

Newsletter creator - Docusaurus maintainer

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Malheureusement, cette page n'a pas encore été traduite en français. Reviens un peu plus tard!

Hi everyone!

This week, we saw a lot of activity on X about the new AI skills system. Personally, what excited me most is the new Firefox release that unlocks interesting things for React developers.

The React Native ecosystem is also super active, with many interesting releases. And I’m sure Expo 55 beta will drop just after we send our email 😅, so make sure to check their blog because it’s coming soon.

As always, thanks for supporting us on your favorite platform:

🦋 Bluesky
✖️ X / Twitter
👔 LinkedIn
👽 Reddit

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People always ask how I keep up to date, it's This Week In React.

Jack HerringtonPrincipal Engineer - Youtuber

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⚛️ React

Agent Skills

A new Anthropic spec is gaining traction in the AI dev community. Skills let agents acquire capabilities on demand via progressive disclosure—lazy-loading only what’s needed to keep context slim. It’s been a hot topic in React this week, with multiple projects shipping open-source skills and tooling:

Skills.sh, a platform launched by Vercel to discover popular open source skills
React Best Practices by Vercel for React and Next.js skills. I also liked the related article from one of the authors (Performance Is Not a Technical Problem).
React Native Best Practices by Callstack, including many React Native optimization skills
Expo Skills for Expo apps and EAS projects
Remotion Skills are trending on X, showing that you can vibe code videos with React 🤪

Firefox 147

You might wonder why Firefox is the headline of the React section? It turns out this release is quite important for React developers, unlocking 3 new APIs that are now available in all browsers 🎉:

View transition types - React is relying on it (document.startViewTransition({update, types})) to conditionally enable its <ViewTransition> component. That component is still canary, but once unflagged, it should now work in all recent browsers!
CSS anchor positioning - An awesome addition to CSS that should replace the need for JS-based positioning libraries many React apps used for dropdowns and tooltips, such as Tether, Popper.js, Floating UI…
Navigation API - This completely redefines the APIs used to build client-side routers / SPAs, providing a clean, centralized way to intercept navigation events, instead of using the clunky history API.

💸 10 Real-World React App Examples to Inspire Your Next Project
👀 React RFC PR - useStore/createStore APIs - A POC of implementing a React Store that is compatible with concurrent rendering, for discussion purposes.
👀 Prettier PR - Upgrade MDX parser - Support for MDX v3 is finally coming.
🔨 TanStack Builder alpha: A website to let you assemble your own TanStack visually. It looks like a convenient visual wrapper around create-tanstack-app.
🗓 React Paris - 🇫🇷 Paris & Online - 26–27 March - React Paris is already 50% sold out - Secure your spot at this premier React event before prices increase by €200 and save an extra 10% with code "TWIR".
📜 useOptimistic Won't Save You - An interactive article showing that it’s not so easy to implement optimistic UI correctly, even with the new useOptimistic and useActionState APIs. This requires a good understanding of how React transitions work.
📜 Inside Turbopack: Building Faster by Building Less - Deep dive into the new default bundler of Next.js and its fine-grained and automatic incremental caching system.
📜 Front-end testing at Preply: shifting left towards component testing - Reorganizing front-end testing at scale by moving toward a Storybook-centric component testing approach.
📜 Adapting Library Logic for React Compiler - The author of TanStack Form explains a problem encountered with the React Compiler that was not reported by the ESLint plugin. Using the compiler panicThreshold helped detect this problem more reliably.
📜 Node.js - Mitigating Denial-of-Service Vulnerability from Unrecoverable Stack Space Exhaustion for React, Next.js, and APM Users - Node.js servers relying on AsyncLocalStorage (used by React RSC and Next.js) can eventually be crashed with a single request containing a deeply nested JSON payload processed recursively. They mitigated the issue in v24.13, but still recommend removing potential attack vectors from your app.
📜 Rebuilding the GitHub pull request experience - This dev explores how GitHub’s PR UI could be much faster, especially for large PRs, and shares lessons learned. His Next.js + React 19 demo shows impressive performance compared to GitHub’s current experience.
📜 React Slot/asChild Composition Pattern - The article also highlights how Base UI composition pattern differs from Radix UI.
📜 Can You Fetch Data with React Server Actions? - Not recommended, but technically possible, with caveats: no caching, requests are POST-only and generally processed sequentially by frameworks.
💸 Make React apps fast where it actually matters. Learn how to diagnose real bottlenecks and fix slow, janky React apps using modern React 19 patterns.
📦 json-render - AI-generated UI with guardrails - Vercel introduced a new generative UI library. It lets users generate more complex dashboards, widgets, apps, and data visualizations from prompts, using a React component catalog you provide.
📦 TanStack Router 1.152 - Allow custom fetch() implementation for server functions - This is useful for interceptors, auth, retry, testing and more (docs).
📦 Base UI 1.1 - New features for Autocomplete, Combobox, Select, Field, various bugfixes - By the way, we recently announced Base UI support in shadcn, and Base UI components are now officially documented.
📦 shadcn 3.7 - New npx shadcn registry add command
📦 GTKX - Build native GTK4 desktop apps with React and TypeScript
📦 Puck 0.21 - Visual editor for React - AI page generation, rich text editing, new Plugin interface
📦 Warper - Fast React virtualization library powered by Rust and WebAssembly
📦 React Error Boundary 6.1 - Fix error type (Error -> unknown), add getErrorMessage(e) helper
📦 Apollo Client 4.1 - Support for @stream directive
🎥 Maximilian Schwarzmüller - Is TanStack Start better than Next.js?

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My favorite resource for keeping up with the React community!

Evan BaconEngineering Manager - Expo

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