Show, Don't Tell

Alexa+ answers, as interfaces.

Voice assistants learned to listen and to talk — but for anything complex, an answer you hear is worse than an answer you can see, edit, and act on. This project shows what Alexa+ conversations look like when a complex answer is a generated, interactive interface: ask for a weekend trip and you get an itinerary card; adjust it in place; book the hotel from a confirm sheet that never charges you without an explicit tap.

Built for the Alexa+ track of Build, Ship, Shape: Amazon Developer Hackathon — entirely on the open standards Alexa+ just adopted: a self-hosted MCP server (spec 2025-11-25, Streamable HTTP — the hackathon's required minimum, served statelessly; see friction-log.md #3 for what 2026-07-28 would take), MCP Apps interactive cards, and an Agent Skill for orchestration.

Why

Voice-only answers fail complex tasks: no memory, no comparison, no action.
Alexa+ can't render interactive cards from MCP servers yet. Instead of waiting, we built that future on the standards themselves — and a simulator that lets you experience it today.

What's in the box

Piece	Where	What it is
MCP server	`packages/server`	Real trip-planning engine: curated dataset + constraint scoring, cross-session trip memory, two-phase booking (quote → confirm)
Cards	`packages/cards`	MCP Apps views. Warm editorial design system, hand-drawn SVG scenes, micro-interactions, `prefers-reduced-motion` support
Agent Skill	`skill/show-dont-tell`	The orchestration rules: when to talk, when to show, confirm-before-charge
Simulator	`packages/simulator`	An Alexa+-style web experience that drives the real server (voice-in, cards-out)
Docs	`docs/`	Architecture, demo script, product feedback, judging map
Friction log	`friction-log.md`	Real developer-experience findings, kept since day one

Quickstart

Requires Node.js ≥ 20.

npm install
npm run build
npm start          # MCP server → http://localhost:3001/mcp

Try it with any MCP client over Streamable HTTP, or run the experience simulator:

npm run dev -w @sdt/simulator   # → http://localhost:5173

Optional: set NTFY_TOPIC to get a real phone push (ntfy.sh) when a booking confirms — the demo's "watch buzzes" moment.

How it works

You: "Plan a weekend in Napa for two"
        │
        ▼
Agent (any MCP host) ──▶ plan-weekend-trip ──▶ engine scores venues
        │                                        against your constraints
        ▼
ui://trip/itinerary.html  (MCP Apps card)
        │
        ▼
Interactive itinerary — adjust in place, pick a hotel
        │
book-hotel  ──▶  quote (requires_confirmation + token)   ← nothing charged
        │
        ▼  you confirm on the card
confirm-booking ──▶ booked · confirmation code · phone/watch buzz

Cross-session memory lives in the server's trip store (conversationId), so "what was that hotel we booked?" works days later.

License

MIT — see LICENSE.