ChartKeep MCP

Inspiration

What it does

ChartKeep is an Alexa+ add-on you can run today without partner-preview access. It is a self-hosted MCP server (spec 2025-11-25, Streamable HTTP) plus a web page that acts as the Alexa+ client: the page sends initialize, tools/list, and tools/call exactly as a real Alexa+ client would. You ask a spreadsheet a question in plain voice English — “Alexa, what’s our best-selling region?” — and the server computes facts from the CSV first, then answers. Charts are ECharts JSON returned by a tool, not guessed in the browser. No Amazon private SDK. No API keys. The sample table never leaves your machine.

Five tools ship in the repo: load_dataset, list_columns, query_facts, suggest_chart, and ask_about_data. There is also a dataset://current resource and a voice-sales-brief prompt. The grounded-facts pattern comes from plotkeep: compute min/max/change/growth in code, then write the sentence from those numbers so the model never invents a figure.

Amazon’s Alexa+ MCP Toolkit and Web Simulator are partner-preview only, so this submission uses the path the FAQ allows: a self-hosted MCP server and a web simulator that speaks the same handshake. When partner tooling opens, point Alexa+ at a public HTTPS URL for /mcp. Until then, this page is the client.

Run with Node 20+: npm install then npm run dev. Open http://127.0.0.1:5173. The MCP server listens on http://127.0.0.1:8787/mcp. Judges can clone and run those two commands.

Built With

• echarts
• express.js
• node.js
• react
• streamable-http)
• typescript
• vite