Hearth v2: an Alexa+ care companion on MCP (Streamable HTTP + MCP Apps)

Hearth lets an older adult talk to Alexa+ about medicines and mood. Their caregiver gets a calm, honest signal only when a real pattern appears, and the person is asked before anything proactive is shared.

Track: Alexa+ (MCP integration on Streamable HTTP + Agent Skill + web simulator).

Run

npm install
npm start            # MCP endpoint http://127.0.0.1:3000/mcp   simulator http://127.0.0.1:3000
npm test             # 24 protocol-level checks

Node 18+ (tested on Node 22). No API keys. All data is fictional and in memory. Open the simulator at http://127.0.0.1:3000 (the Origin allow-list covers localhost and 127.0.0.1 on the chosen port).

Demo video: docs/demo.mp4 · Requirements and evidence: docs/COMPLIANCE.md · Deploy: docs/DEPLOY.md

Related MCP server: hearth-mcp

What makes it different

Personalised routine model: the "no morning activity" threshold is median + max(60 min, 4×MAD) of the person's own first-activity times (usual 07:18, alert after 08:18), not a fixed hour.

Files

• server.js MCP server (8 tools, 3 resources incl. the ui:// view)

• src/store.js care logic, personalised baseline, demo clock, change events

• src/eventStore.js resumable SSE event store

• ui/dashboard.html the MCP App view (no SDK, plain JSON-RPC over postMessage)

• public/index.html Alexa+ simulator: real MCP client (sessions, SSE, consent) and an MCP Apps host

• skills/hearth-care/SKILL.md Agent Skill

• test.mjs spec-level tests (security, lifecycle, UI metadata, consent, push, resume)

Try the demo (2 minutes)

1. As Amina: "Good morning", "I feel tired".

2. Press +3 h, then ★ Run proactive check: Alexa+ asks Amina for consent (MCP elicitation) before telling Salma.

3. Switch to Salma, "How is mum doing?": the dashboard renders as an MCP App; press Refresh (app-only tool).

4. Back to Amina: "I fell" gives the emergency-first response and an urgent alert without a consent step. Watch Live MCP traffic and push stream on the right.

Honest limits

• Not tested on a real Alexa+ device or with third-party MCP hosts (Claude, ChatGPT, VS Code). The simulator is our own client/host; phrase-to-tool mapping is rule-based.

• The simulator's MCP Apps host uses a sandboxed srcdoc iframe (opaque origin) instead of the spec's recommended double-iframe sandbox proxy on a separate origin. A production host needs the proxy.

• Home signals are simulated, not connected to Ring. No auth, persistence or encryption yet. Not a medical device.

• To expose the server beyond localhost set HOST, ALLOWED_ORIGINS, ALLOWED_HOSTS and add authentication first.

Roadmap

Household auth (OAuth), persistence, real Ring/IoT events, clinician-ready weekly report, Bedrock summaries (AWS mini-challenge), sandbox proxy host.