Show HN: C1 – an OpenAI-compatible LLM API that renders real UI instead of md

We’ve been working on C1, an OpenAI-compatible API that returns real UI components—buttons, forms, layouts—instead of markdown or plain text. The goal is to help developers build agents and copilots that go beyond conversation and support real interaction, without writing front-end glue code.

It works like a regular chat completion endpoint: pass in a prompt and tools, get back a structured UI that users can click, fill out, or navigate.

Explainer video: https://www.youtube.com/watch?v=jHqTyXwm58c Link to docs: https://docs.thesys.dev/guides/solutions/chat

Would love feedback from anyone building LLM-powered interfaces or agentic tools.