This is a backend written in go that's wire-protocol compatible with the (catchy named) Vercel AI UI SDK; which is an SDK for helping to build AI chat apps. The original Vercel AI SDK backend is in typescript.

I think they really missed the opportunity to add in resumable streaming after a dropped SSE connection, or multi-device support. Because these SDKs are easy to drop-in to your applications, but hard once you actually try and build resilient systems on top of them. Systems that can heal from dropped connections, or support multiple users or multiple devices.