Hearth

An end-of-day voice diary for Alexa+ that remembers what you said you'd do.

Built for the Build, Ship, Shape: Amazon Developer Hackathon 2026 (Alexa+ track, with the AWS Builder mini challenge).

The problem

If you're in your twenties, living alone, far from family, and buried in work or classes, the day ends with nobody to tell about it. The small promises you said out loud ("I'll call Mom back", "I need to book the dentist") evaporate by morning, and the people you meant to call don't hear from you.

Hearth is the thing you talk to at the end of the day. It listens like a diary, and it quietly keeps track of what you said you'd do.

• Talk freely. Rant, reflect, ramble. Hearth acknowledges what you said, warmly and briefly.

• It remembers your promises. Anything you say you'll do, need to do, or promised someone becomes a to-do with a due date, pulled out of ordinary speech.

• Ask it later. "What's due tomorrow?" "What did I say I'd do this week?" "What's the most important thing right now?" "I just called my sister."

• It notices patterns. "Deadlines came up on 3 of the last 6 days you talked to me." Observations only.

What Hearth deliberately is not: therapy, coaching, or crisis support. It never gives advice and never offers mental-health services. It acknowledges, remembers, and notices.

Related MCP server: AI Diary MCP Server

How it works

 you ──voice──▶ Alexa+ (orchestrator) ──MCP, Streamable HTTP──▶ Hearth MCP server ──▶ SQLite
                                                                    │
                                                                    └──▶ Amazon Bedrock (Converse API)
                                                                         extraction · acknowledgement · reflection

MCP tools

Run it

Requires Python 3.12+.

python -m venv .venv && . .venv/bin/activate
pip install -r requirements.txt

# Terminal 1: the MCP server
python -m hearth.server                  # http://127.0.0.1:8765/mcp   (health: /health)

# Terminal 2: the Alexa+ simulator
python -m simulator.app                  # http://127.0.0.1:8080

Or run both with one command: ./scripts/start.sh (your own diary, kept in ~/.hearth/hearth.db) or ./scripts/start.sh demo (the seeded demo data).

Open http://127.0.0.1:8080. Use Talk (Chrome/Edge microphone), type, tap a suggested line, or press Play a demo evening.

Bedrock: export AWS credentials, AWS_REGION and HEARTH_BEDROCK_MODEL (default: Claude Haiku 4.5 via a us. inference profile; see .env.example). python scripts/check_bedrock.py verifies your setup first. Bedrock does the extraction, acknowledgements, reflections and the simulated Alexa+ tool routing; dates are resolved in code, not by the model. The server's /health shows "llm_engine": "bedrock" when it's live. With no credentials everything still runs on the offline fallback, and the trace panel labels which engine produced each reply.

A week of history for the demo: python scripts/seed_demo.py (fresh DB only) backfills six evenings so reflections and overdue items have something real to show.

Tests: python -m pytest -q. They cover date parsing, extraction, de-duplication, ranking, fuzzy completion, reflection, the Bedrock path (with a fake client), fallback on Bedrock failure, and an end-to-end run that boots the server and drives it with an MCP client over Streamable HTTP, asserting protocol >= 2025-11-25.

Putting it in front of real Alexa+

The server is a spec-compliant Streamable HTTP MCP endpoint, so it is what Alexa+ needs to connect to. Registering it as an add-on goes through Amazon's tooling (the Alexa AI CLI or the Add-on Agent Skill; see the Alexa+ MCP QuickStart). That registration step has not been done or tested from this repo. The simulator is the path this submission demonstrates.

To serve it publicly: docker build -t hearth . && docker run -p 8765:8765 -v hearth-data:/data hearth behind HTTPS. Bind with HEARTH_HOST=0.0.0.0 (the default localhost binding rejects other Host headers with HTTP 421).

Honest limits

• One user. Tools take a user_id that defaults to me. A real deployment should map Alexa+ account linking to it; OAuth is not implemented.

• Simulated orchestration. In the simulator, tool choice is made by Bedrock tool-use (or simple rules offline). Real Alexa+ does its own routing from the tool descriptions the server advertises.

• Offline fallback is simpler. The regex/keyword engine handles common phrasings ("I need to…", "I told my sister I'd…", "remind me to…") but is much weaker than the model on nuance.

• No crisis handling by design. This is a product-scope decision (see above), not an oversight; anyone shipping this to real users should think carefully about what a diary product should do when someone writes something alarming.

• Data is stored unencrypted in a local SQLite file.

Layout

hearth/       MCP server, service logic, Bedrock + fallback language layer, SQLite store
simulator/    Alexa+ simulator (Starlette backend, single-file UI)
scripts/      seed_demo.py, check_bedrock.py (verify AWS access), start.sh (run everything)
tests/        unit + end-to-end tests

MIT licensed.