Agent backends are maturing, but the interaction layer remains fragmented. When an agent needs to show progress, request consent, collect structured input, or return an interactive result, many teams still glue chat bubbles to custom React components.

This session compares three emerging approaches. AG-UI streams agent state and tool progress into the application. A2UI lets an agent describe a trusted interface as structured data. MCP Apps lets a tool return an interactive experience inside a sandboxed surface. In one end-to-end expense-approval demo, we will wire all three together: stream the plan, pause for authorization, render a form, and return an interactive audit view.

Attendees will leave able to explain where the protocols overlap, choose the right boundary for state and UI generation, implement consent-first actions, and design an agent interface that remains testable and secure.

Audience: Front-end, full-stack, and agent developers building interactive web applications.
Format: 45–60-minute technical talk with one end-to-end live demo.
Demo: An expense-approval agent using AG-UI state events, an A2UI form, and an MCP App audit view.
Technology reference: https://github.com/ag-ui-protocol/ag-ui
Materials: Talk-specific repository, slides, and recording are not yet published.
Vendor scope: Protocol-focused and vendor-neutral; web examples use React and TypeScript.