React Native + Go Backend

A React Native application demonstrating communication with a local Go HTTP server using JSI and JSON-RPC 2.0.

Overview

This project showcases how to build a fast mobile application where:

• React Native handles the UI with the New Architecture (Fabric + TurboModules)
• Go runs as an embedded HTTP server providing JSON-RPC APIs
• Native modules manage the Go server lifecycle
• Business logic is handled via JSON-RPC calls over HTTP

Prerequisites

• Node.js 18+
• Go 1.24+
• gomobile: go install golang.org/x/mobile/cmd/gomobile@latest
• iOS: Xcode 15+, CocoaPods
• Android: Android Studio, JDK 17+

Quick Start

Setup Build Environment

First time setup (installs gomobile and required dependencies):

cd backend
make setup

Build Go Backend

iOS:

cd backend
make ios

Android:

cd backend
make android

You can also run make help in the backend directory to see all available targets.

Run the App

iOS:

cd mobile-app
npm install
npx pod-install
npx expo run:ios

Android:

cd mobile-app
npm install
npx expo run:android

Project Structure

react-native-go/
├── backend/
│   ├── mobile_api.go      # Mobile API for server lifecycle
│   ├── http_server.go     # JSON-RPC HTTP server
│   └── Makefile
└── mobile-app/
    ├── src/
    │   ├── NativeGoServerBridge.ts    # TurboModule spec
    │   ├── GoServerBridgeJSI.ts       # JSI wrapper
    │   └── JsonRpcClient.ts           # JSON-RPC client
    ├── android/               # Android native code
    └── ios/                   # iOS native code

How It Works

Native Layer (TurboModule)

The native modules expose 3 synchronous methods via JSI:

interface Spec extends TurboModule {
  readonly startServer: () => number;
  readonly stopServer: () => boolean;
  readonly getServerPort: () => number;
}

Go Backend Layer

The Go backend provides a mobile API for lifecycle management:

type MobileAPI struct{}

func (m *MobileAPI) StartServer() int {
    return StartHTTPServer()
}

func (m *MobileAPI) StopServer() {
    StopHTTPServer()
}

func (m *MobileAPI) GetServerPort() int {
    return GetHTTPServerPort()
}

And handles business logic via JSON-RPC:

func (s *HTTPServer) handleRequest(req JSONRPCRequest) JSONRPCResponse {
    switch req.Method {
    case "getGreeting":
    case "getCurrentTime":
    }
}

JavaScript/TypeScript Layer

Start the server and make JSON-RPC calls:

import GoBridge from './GoServerBridgeJSI';

const port = GoBridge.startServer();
const client = new JsonRpcClient(`http://localhost:${port}`);
const result = await client.call('getGreeting', { name: 'World' });

Adding New API Endpoints

To add a new endpoint, modify only the Go backend:

case "myNewMethod":
    params, ok := req.Params.(map[string]interface{})
    if !ok {
        return s.errorResponse(req.ID, -32602, "Invalid params")
    }
    result := doSomething(params)
    return JSONRPCResponse{JSONRPC: "2.0", Result: result, ID: req.ID}

Use from React Native:

const result = await jsonRpcClient.call('myNewMethod', { param: 'value' });

No native code changes required.

Common Issues

gomobile not found

export PATH=$PATH:$(go env GOPATH)/bin
gomobile init

Cannot find Gobridge.xcframework

cd backend
make ios

Cannot find gobridge.aar

cd backend
make android

Development Workflow

Changes to Go Code

1. Edit backend/*.go files
2. Rebuild: cd backend && make ios or make android
3. Rebuild app: cd mobile-app && npx expo run:ios or npx expo run:android

License

This project is licensed under the MIT License - see the LICENSE file for details.

Show Your Support

If this project helped you, please give it a star! ⭐

Support

• Issues: GitHub Issues

Acknowledgments

• React Native - Learn once, write anywhere
• Expo - Platform for universal React applications
• go-mobile - Go bindings for mobile
• status-mobile - Real-world Clojure/Go integration

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