Your agent says it is working. Is it calling a tool, waiting for approval, recovering from a failure, or stuck?

Traditional loading indicators are not enough for long-running agent workflows. Users need useful progress, clear choices, safe interruption points, and a way to recover when part of the run fails.

This session shows how to design a frontend around the agent lifecycle. In a live Next.js demo, we will evolve a basic chat interface into an application that streams progress, displays structured tool results, requests approval before side effects, and lets the user cancel, retry, or resume work.

CopilotKit and the Vercel AI SDK provide the implementation example. AG-UI carries agent events and shared state. A2UI demonstrates host-rendered declarative interfaces, while MCP Apps demonstrates interactive views returned by tools. The goal is not to use every protocol at once, but to understand which frontend problem each one addresses.

Attendees will leave able to:

- Model an agent run as visible UI states
- Show useful progress without exposing internal reasoning
- Render structured results instead of long chat messages
- Design approval, cancellation, retry, and recovery interactions
- Choose when application components, declarative UI, or tool-provided views fit

The frontend should not make an agent look busy. It should help the user understand what is happening and what they can do next.