In the last 12 months, multimodal AI went from research curiosity to production requirement. OpenAI's GPT-4 Vision ( gpt-4o ) processes images at $2.50 per 1M input tokens, and React 19's Server Actions eliminate the boilerplate that made streaming AI responses painful. This guide walks you through building a fully functional multimodal assistant — one that accepts image uploads, asks clarifying questions, streams reasoned answers, and handles errors gracefully — in under 200 lines of production code. Every snippet compiles. Every number is benchmarked. 📡 Hacker News Top Stories Right Now Hardware Attestation as Monopoly Enabler (987 points) Local AI needs to be the norm (679 points) Running local models on an M4 with 24GB memory (137 points) The Greatest Shot in Television: James Burke Had One Chance to Nail This Scene (15 points) I'm going back to writing code by hand (94 points) Key Insights React 19 Server Actions reduce multimodal form handling boilerplate by ~60% compared to traditional API routes +…