Next.js + Bun + TypeScript app to compare two LLMs side by side using AI SDK v5 and OpenRouter.

1. Create .env.local:

OPENROUTER_API_KEY=your_key
APP_URL=http://localhost:3000
APP_NAME=LLM Arena

2. Install deps:

bun install

3. Run dev:

bun run dev

Open http://localhost:3000.

• Model list is fetched from /api/models (server proxies OpenRouter).
• Chats stream via /api/chat using the selected modelId.