Inspiration
I built TheOne because I wanted to keep talking without hunting through old chats. One chat soon creates a second problem: work for different topics gets mixed together. For this event I focused on one practical failure: a moving bill gets filed under the move, then the user says it belongs in the budget. A retry should not recreate the mistake, and an old correction should not erase a newer one.
What it does
TheOne Topic Memory exposes six tools to an MCP host: list_topics, create_topic, suggest_route, read_topic, save_note and move_note. Each topic has separate persistent notes. Saves use a stable request key; retries return the existing note's current receipt. Corrections move the same note atomically, with an expected version to reject stale changes.
The 90-second video shows actual calls through the official MCP client and HTTP server. The browser host uses scripted buttons and a synthetic 480 EUR bill. Captured screenshots are held and edited for pacing. There is no Alexa device, voice interaction or LLM inference in this demonstration. This entry follows the self-hosted MCP server path in the Alexa+ track.
How we built it
The server imports and invokes @modelcontextprotocol/sdk 1.32.1 at runtime, with Streamable HTTP and MCP protocol 2025-11-25. Node.js 24 supplies SQLite persistence; Zod defines the tool schemas. The integration test connects the official SDK client to a real HTTP endpoint and asserts the negotiated protocol, isolation, retries, conflicts, atomic correction, stale-version refusal, restart persistence and invalid Origin/Host handling.
The server binds to loopback. It uses a separate database and does not touch the user's existing DSH sessions. Judges can clone the public branch, run npm ci --ignore-scripts and npm test inside examples/amazon-alexa-mcp, then start the server or browser host. No cloud subscription or model credentials are required. Source is MIT licensed.
The base TheOne repository history starts on September 30, 2026, within the submission window. This MCP extension reuses that plugin. This branch starts from the published build-fix commit 5e5e395 and reuses its deterministic rule router unchanged. The MCP entry point, tool schemas, SQLite memory, retry/correction workflow, client demos, browser host and HTTP tests were added on October 11, 2026. Codex assisted with implementation, tests, capture and documentation. No AWS services are used.
Challenges we ran into
A receipt cannot simply retain the original topic forever: after a correction, replaying the original save must return the corrected note, rather than move it back or leave a duplicate. We also had to distinguish a stale correction from a transport failure so the demo only reports a refusal when the server actually returns the expected version error.
The existing deterministic route hint can misclassify a message whose subject points to one topic while its requested action points to another. It is labeled as a hint; a future agent host should ask when intent is ambiguous. The video tests explicit correction, not model routing accuracy.
Accomplishments that we're proud of
The actual HTTP test passes. The demo preserves one note across a topic correction and repeated saves, rejects an outdated correction, and rereads the corrected workspace. The source is public with local run instructions, and every demonstrated result can be reproduced without a paid API.
What we learned
Topic memory needs a correction workflow as much as it needs routing. Stable request keys and version checks make this workflow testable before adding a model or voice host. The official SDK made it straightforward to test client and server together rather than infer correctness from a mocked transport.
What's next for TheOne Topic Memory
Connect a real agent host and evaluate ambiguity handling with clearly labeled data. Remote deployment would need TLS and per-user authorization. The current single-owner prototype is not a multi-user security boundary; a connected local host can read all of the owner's topics. No Alexa certification or production readiness is claimed.
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