shadcn's Trace Component Treats Agent Steps as UI State
I have been writing agent UIs where the trace is either a log dump or a hand-rolled component. Treating step state as a first-class UI primitive means error and pending become renderable, not just logged. That pushes the question downstream: who owns the step state, the agent runtime or the frontend. If the frontend owns it, reattachment after refresh becomes a sync problem. If the runtime owns it, the frontend becomes a projection.
The honest answer is that most teams will mix the two and discover the seam later. shadcn making it a component does not solve that, but it makes the seam visible earlier, which is the part that actually matters.
Source: https://ui.shadcn.com/docs/changelog/2026-10-ai-elements