How to build a Custom Expo Module | Foundation Models Module

Sometimes you need a native feature that no existing library covers. Or maybe you just want full control over how your model works. That's where custom expo modules come in. Take the foundation models API for example. It requires you to define generables, the structure of the data you want the local LLM to generate and you have to define this directly in Swift. In this case, writing a custom Expo module makes perfect sense. The good news is that Expo modules are built to integrate seamlessly with the Expo workflow. Whether you're using development build, pre-build, or continuous native generation, there is no extra configuration needed. Just import your module where you need it and you're good to go. But wait, there's more! Even if you are not using Expo in your React Native project, Expo modules are still likely your best option. They work great in plain React Native projects, too. And if you want inspiration, just check the Expo examples repo with over 100 production ready modules powering apps like Bluesky, Starlink, Coinbase, Notion Calendar, Brex, and many, many more. Resources: 👨‍💻 Source Code https://github.com/betomoedano/founda... 📂 Expo Modules API https://docs.expo.dev/modules/overview 🧪 Expo Modules Examples https://github.com/expo/expo/tree/mai... 🦋 Bluesky Expo Modules Examples https://github.com/bluesky-social/soc... 🍎 Apple Foundation Models https://developer.apple.com/documenta... 🎥 WWDC Meet Foundation Models    • WWDC25: Meet the Foundation Models framewo...   Learn more about Expo Modules 🎥 How to wrap native libraries    • How to create a native module with the Exp...   🎥 How to create a native module    • How to create a native module with the Exp...   ⌚️ Timestamps ⌚ 00:00 Intro 03:10 Getting Started 06:11 Setting Up a Local Expo Module 12:34 Simplifying Module 15:59 Creating Module Records 18:55 Adding Availability Check 27:09 Simple Text Generation 38:27 Structured Data with Generables 47:41 Streaming Text 01:04:28 Streaming Generables 01:10:12 Conclusion #Expo #ReactNative #reactnativetutorial