# rn-watch-connect

rn-watch-connect is a library for communicating with your companion watchOS app from your Expo and React Native app. It's built for Expo, with the Expo Modules API, on top of Apple's [WatchConnectivity](https://developer.apple.com/documentation/watchconnectivity).

- [Installation](https://rn-watch-connect.vercel.app/docs/installation.md): Requirements (Expo SDK 57+, iOS 16.4+, iOS only), npm install, rebuilding the native app, a quick start with sendMessage and onMessageReceived

## AI

- [AI agents](https://rn-watch-connect.vercel.app/docs/ai-agents.md): llms.txt (index), llms-full.txt (all docs in one file), per-page Markdown (/docs/<page>.md), pointing an agent at the docs from AGENTS.md or CLAUDE.md, the Copy Markdown and Open in ChatGPT / Claude / Cursor page actions

## API

- [Watch status](https://rn-watch-connect.vercel.app/docs/watch-status.md): isWatchSupported, isWatchPaired, isWatchAppInstalled, isWatchReachable, watchActivationState, onReachabilityChanged, onWatchPairedChanged, onWatchAppInstallChanged
- [Messages](https://rn-watch-connect.vercel.app/docs/messages.md): sendMessage, sendMessageWithoutReply, onMessageReceived, onMessageWithReply and its reply function, replyToMessage (deprecated)
- [Data Messages](https://rn-watch-connect.vercel.app/docs/data-messages.md): sendDataMessage, sendDataMessageWithoutReply, onDataMessageReceived, onDataMessageWithReply and its reply function, replyToDataMessage (deprecated)
- [Application Context](https://rn-watch-connect.vercel.app/docs/application-context.md): updateApplicationContext, applicationContext, receivedApplicationContext, onApplicationContextChanged
- [User Info](https://rn-watch-connect.vercel.app/docs/user-info.md): transferUserInfo, cancelUserInfoTransfer, outstandingUserInfoTransfers, onUserInfoReceived, onUserInfoTransferFinished
- [File Transfer](https://rn-watch-connect.vercel.app/docs/file-transfer.md): transferFile, cancelFileTransfer, outstandingFileTransfers, onFileReceived, onFileReceiveFailed, onFileTransferFinished
- [Error codes](https://rn-watch-connect.vercel.app/docs/errors.md): WatchConnectErrorCode: every Error code, and why to match on code, never on message

## Upgrading

- [Migrating from 1.x to 2.0](https://rn-watch-connect.vercel.app/docs/migration.md): Breaking changes, behaviour changes to check, deprecated APIs (replyToMessage, replyToDataMessage, replyId) and new optional features in 2.0