Voltra Launch, React Navigation 8 Alpha, Brownfield “Brownie”, and React Native AI x llama.rn

Authors
Michał Pierzchala
Principal Engineer
@
Callstack

Hey,

It’s Michał with the first update of 2026!

I hope your new year’s resolution are holding up (hint: focus on making habits and enjoying the process, not just goals) and you’re well rested to build new things. And if you’re not ready to ship just yet, here’s a bunch of news and insights from React Native community and Callstack Incubator in December 2025 and early January to prime you with inspiration instead of FOMO. Let’s go!

Disclaimer: This issue may be clipped in your inbox, so it might be best to open it in the browser.

Community highlights

  • Hermes now has a blog: Tzvetan from Hermes team went on a journey of converting his famous X posts about Hermes JS engine internals to a structured blog in the projects’ GitHub repo. We highly recommend reading all of it!
  • Debug Like a Senior - React Native Performance Panel: Mariusz shares how to efficiently use new Performance Panel in React Native DevTools. He goes through the panel's features, such as Scheduler tracks, Components, Threads, and also reveals some hidden gems. Can you find them?
  • MLX Swift with React Native: MLX is a NumPy-like array framework designed for efficient and flexible machine learning on Apple silicon, brought to you by Apple machine learning research. There’s now a React Native library wrapping Swift MLX using Nitro Modules.
  • RNSec: React Native Security Scanner: a new project that allows you to detect vulnerabilities, hardcoded secrets, and security misconfigurations before they reach production. It’s a CLI that also creates a rich HTML report. Supported rules verify issues around storage, network, WebView, logging, config, third-party SDKs and more.
  • React Native Wrapped 2025: A Month-by-Month Recap of The Year: together with Szymon Rybaczk we’re looking back at the year React Native turned 10 and the ecosystem doubled down on the New Architecture. The article provides a month-by-month record of 2025, covering major framework releases, the Legacy Architecture freeze, React 19 integration, and notable developments across tooling, performance, styling, native modules, Expo, and platform adoption.

Callstack Incubator highlights  

Voltra

Long-teased by Szymon, it’s finally out! Voltra is a React renderer for iOS Live Activities, Dynamic Island and Widgets. With Voltra you can build dynamic live activities running locally, or driven from a server with push notifications, using only TypeScript. No Swift knowledge required. The library is a joint collaboration between Szymon and its original author Saúl.

Voltra is a new library for building ios Live Activities with React Native. It's created by @ChmalSzymon and @saul_sharma

Gave it a try and I must say its really amazing, the updates are instant! All you need is the expo plugin too.

Heres a quick example I setup in less than… pic.twitter.com/umcFdglNRI

— Daniel Williams (@Danny_H_W) December 16, 2025

React Native Brownfield

Oskar is working on a new addition to our Brownfield library: a two-way, end-to-end type-safe, cookie-like storage for communicating between Native and React Native called Brownie. It’s gonna be pretty sweet addition to your hybrid apps, or incremental migration, so that you can be sure that there’s a single source of truth for the state shared by native and React Native components. Watch out for release in the upcoming weeks!

Sneak peek of the new thing I'm working on 👀

It's a two-way end-to-end type-safe Brownfield Store called Brownie ✨

- Generate a shared store from TypeScript spec
- Reactive updates on both Native and React Native
- Data lives on the native side

Here is a demo: pic.twitter.com/e3Er5mVySB

— Oskar Kwaśniewski (@o_kwasniewski) December 22, 2025

And if you haven’t heard about it already, you can also pair the React Native Brownfield library with Expo too! You’ll need to prebuild the app, so no CNG yet, but we may be working on something in this area 🤫.

You can embed an Expo app in your iOS and Android apps using React Native Brownfield library _today_.

We use this setup in production for a few years now at @callstackio. It requires `expo prebuild` and some changes, so the experience could be better. Working on it pic.twitter.com/HTW91J9A3u

— Michał Pierzchała (@thymikee) December 16, 2025

React Native Pager View

Another great contribution by Oskar, driven by the needs of Vercel’s v0 mobile app. This one is about rewriting the slightly buggy UIKit implementation to SwiftUI, which solves some of the long standing issues we’ve found in many high-profile apps out there using the library. Upgrade PagerView to v8 and let us know how it works for you and your users.

React Native Pager View 8.0.0 is out 🎄✨

This release is a full rewrite of the iOS codebase in SwiftUI ⚡

This rewrite solves many long-standing issues in Pager View. Looking forward to your feedback! pic.twitter.com/A1cBfPidnE

— Oskar Kwaśniewski (@o_kwasniewski) December 17, 2025

React Native Bottom Tabs

The React Native Bottom Tabs library by Oskar was successfully incubated and is now part of Callstack organization. This means we treat it as stable, feature ready, and we keep maintaining it. Well done Oskar! 🎉

The React Native Bottom Tabs library has moved from Callstack Incubator to the main Callstack organization 🎉

You can checkout the repo here: https://t.co/JMsqP7Pre1

— Oskar Kwaśniewski (@o_kwasniewski) December 10, 2025

Rozenite

Szymon is building yet another DevTools plugin using Rozenite, this time it’s about profiling import cost for Metro bundles. You, or Claude Code, can build your own plugins using Rozenite too. 😁

Prototyping a new profiler to identify which modules are the most expensive to import and evaluate, so you can decide which ones to lazy-load after the app has loaded. pic.twitter.com/BCD9NWv97f

— Szymon Chmal (@ChmalSzymon) December 13, 2025

React Native AI x llama

Wake up, there’s new runtime compatible with React Native AI: llama.rn.

We just released new package: @⁠react-native-ai/llama! 🎉

It brings @aisdk bindings for llama.rn!

Our goal is to make React Native AI the go-to place for various LLM engines with fist-class @aisdk integration! pic.twitter.com/66hqSw2xdV

— Szymon Rybczak (@SzymonRybczak) December 22, 2025

It allows you to use the same AI SDK interface with llama.cpp project (through llama.rn) to run GGUF models. Such as the newly released Gemma 3 270M.

We’re also working on ONNX support, so expect that next month or so.

new LLM from Google Gemma 3 270M works seamlessly with react-native-ai! 🔥🔥

you can use it via new @⁠react-native-ai/llama provider! 💯 pic.twitter.com/9gdtiJ4OLs

— Szymon Rybczak (@SzymonRybczak) January 7, 2026

React Navigation

Satya is fearlessly closing issues, PRs, and delivering new features for the upcoming React Navigation 8 release. And now you can have a sneak peek of what’s coming with the latest alpha release! It features native bottom tabs, accessing route, navigation, and state for any parent screens, better inferred types, and more. Check the blog post too.

React Navigation 8 alpha is here 👀

📝 Highlights

- Native Bottom Tabs by default
- Access to route, navigation, & state for any parent screens
- Better TypeScript types for static configuration
- Push history entries without pushing screens

And many more... pic.twitter.com/ggG2qfpkOE

— React Navigation (@reactnavigation) December 19, 2025

SceneDelegate RFC

Artur converted his draft PR into a formal RFC for SceneDelegate migration for iOS. Since iOS 26 started deprecating AppDelegates, it’s becoming inevitable that we’ll need to migrate to UIScene lifecycle. Read the proposal and leave some comments or reactions. We hope to ship this in the upcoming months.

My first RFC for React Native has just dropped 🚀

In the face of recent deprecations in iOS 26, UIScene lifecycle will become required sooner than later. My new RFC and draft implementation adopt it and bring SceneDelegate support to React Native: https://t.co/qj8TEWbJgu

— artus9033 (@artus9033) December 17, 2025

Storybook explorations

Since Danny joined Callstack recently, he’s been hacking on a few things in his spare time outside of Incubator, but closely with its members, such as Szymon. Together they prototyped a small app that streams simulator screens to a unified web UI, so that you can work on your React components in Storybook and see how they work at all platforms all at once. Should we followup with a more robust library for that? Let us know!

Wouldn't it be nice to have all platforms in a single @storybookjs window?@ChmalSzymon and myself worked on this prototype to stream your local simulators to the Storybook canvas. Let us know if you're interested in this! pic.twitter.com/IjBe4g0nOz

— Daniel Williams (@Danny_H_W) December 16, 2025

Create React Native Library (Bob)

There’s a new version of CRNL which supports latest Rect Native, reworked its CLI, fixed Nitro View template and some issues on Windows. Hopefully next version will include Harness by default, so you’ll be able to test your libraries end-to-end with Jest.

New version of create-react-native-library is here 🔥

- React Native 0.83
- Fixed issues on Windows (thanks @_atlj)
- Fixed Nitro View template
- Reworked CLI pic.twitter.com/Pchj12Yo6r

— Satyajit Sahoo (@satya164) December 11, 2025

Guide

React Native Developer’s Guide to Horizon OS

As a culmination of the Meta Quest–focused content we’ve been publishing recently, we’re releasing a brand-new guide! The React Native Developer’s Guide to Horizon OS shows how React Native apps can run on Meta Quest headsets without switching stacks. Because Meta Horizon OS is built on Android, React Native works where you’d expect: same core abstractions, familiar tooling, and a new spatial form factor.

The guide is written for React Native developers who already ship on mobile or web and want a practical, no-hype path into VR.

It covers:

  • How React Native fits into Meta Horizon OS and what actually changes in VR
  • Setting up and running React Native apps on Meta Quest with Expo
  • Library compatibility, ecosystem constraints, and Quest-ready alternatives
  • App categories that make sense in VR and how to think spatially
  • Debugging, performance profiling, native modules, and daily workflows
  • Building, signing, and publishing a production-ready app to the Meta Horizon Store

The result is a clear, hands-on guide to building and shipping real React Native apps on Meta Quest, using the skills and workflows you already have.

Blog

If you prefer to jump straight to the blog post versions of our releases, there you go:

Podcasts, talks and interviews

Live Streams

  • Building iOS Live Activities with React recording
  • React Native 0.83: A Stability-Focused Release With Surprisingly Big Quality-of-Life Wins recording

Upcoming events: React Universe Meetup x Zalando

On January 29, 2026, together with Zalando, we’re hosting the first event of 2026: React Universe Meetup x Zalando in Berlin.

Join us to hear lessons from the early adoption stage of building a responsive video experience at Zalando, running LLMs locally on mobile devices in React Native apps, and hacking your health and productivity with React Native.

That’s it for the December edition. Hope you’re off to a great start to the year. Let's catch up online or in real life!

‍

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