NeMo Agent Toolkit - UI

Why it matters

How a front end talks to an agent decides what the user sees mid-run and whether the agent can ask the user anything at all. This UI exposes both transports side by side.

What to practise

Serve the simple calculator workflow with nat serve, point the UI at it with NAT_BACKEND_URL, and choose the Chat Completions — Streaming HTTP endpoint with intermediate steps turned on to see the agent’s steps beside its answer. Then serve the human-in-the-loop calculator, switch the WebSocket toggle on with the same schema, and answer the agent when it pauses for your input in a modal. Note that the README makes WebSocket mode a requirement for human-in-the-loop workflows.

How it fits

The two modes are 2.5.1’s choice between SSE and WebSocket, and the steps panel is its separation of intermediate steps from output. The paused turn is the kind of bounded interaction that 2.5.2 has to recover after a reconnect and that 2.5.3 turns into an explicit branch.