Hakgyo V2

Hakgyo V2 is a Bun/Turborepo monorepo with a Next.js backend/web client and an Expo mobile client. Both clients use Better Auth and the same type-safe tRPC API hosted by Next.js.

Local Setup

bun install
cp apps/web/.env.example apps/web/.env
cp apps/mobile/.env.example apps/mobile/.env

Configure apps/web/.env with the Neon database connection and Google OAuth credentials. Set EXPO_PUBLIC_API_URL in apps/mobile/.env to the origin of the Next.js app:

• iOS simulator: http://localhost:3000
• Android emulator: http://10.0.2.2:3000
• Physical device: use the computer's LAN address, such as http://192.168.1.10:3000

Start both apps:

bun run dev

The API is served at /api/trpc and Better Auth is served at /api/auth. The mobile client forwards Better Auth's securely stored session cookie to tRPC protected procedures.

Google OAuth

Create a Google OAuth client with application type Web application. Add these authorized redirect URIs:

http://localhost:3000/api/auth/callback/google
https://your-domain.com/api/auth/callback/google

Better Auth completes OAuth on the Next.js backend and redirects the native app through the hakgyo:// scheme. The native bundle ID and Android package are both com.rorez.hakgyo.

Vercel and Mobile

Deploy apps/web as the Vercel project and configure all variables from apps/web/.env.example. Set APP_URL to the stable production origin, not a preview deployment URL. Better Auth and Zoom OAuth both derive their callback URLs from this value.

For production mobile builds, set:

EXPO_PUBLIC_API_URL=https://your-domain.com

EXPO_PUBLIC_API_URL is embedded in the mobile bundle and is not a secret. Rebuild or publish an EAS Update when changing it.

Shared API Contract

packages/api exports only the AppRouter TypeScript type. Runtime server code remains in apps/web, while Expo gets end-to-end input and output types without bundling Prisma or server credentials.