Hey guys,

I wanted to share an open-source chat app that we built last week as part of the T3 Clone Competition. It’s a minimal AI chat app inspired by t3.chat, with most of the core features replicated:

• Google + Anonymous auth with chat linking
• Multi-model support (OpenAI, OpenRouter)
• Real-time updates with Convex
• File uploads (PDF, image, text)
• Chat branching and shareable threads
• Syntax highlighting, markdown support
• Bring-your-own-key support (keys never touch the server)

The branching + share feature was the trickiest—it required snapshotting and spinning up isolated threads when someone replied to a shared chat.

You can try it live at 👉 https://ch4t.codse.com
And the source code is open at 👉 https://github.com/codse/chat

Not perfect (still missing image generation and smoother streaming), but it was a fun deep dive into real-time UX.

What do you think? What would you improve or build next?