MCP server · spec 2025-11-25 · Streamable HTTP

Ask out loud if the northern lights are worth going out for.

Aurora Odds reads the solar wind that is already on its way to Earth and answers for your town, in one sentence you can hear: go outside now, bring your phone, or stay in. It is an MCP server, so a voice assistant like Alexa+ can call it.

3 read-only toolsEvery 10 min new forecastAny town on Earth, north or southNo key needed

Quiet sky tonight? Hear the night of the May 2024 superstorm

Try it: speak, type, or tap a question

Answers appear here and are read aloud.

As in Alexa+, a language model (Llama 3.3 70B on Cloudflare Workers AI) decides which tool to call and with what. The sentence you hear is the MCP server's own, never the model's. If the model is busy, the page falls back to simple keyword matching.

Connect any MCP client

One Streamable HTTP endpoint, stateless, no sign-in. Every tool returns a speech string written to be read aloud as it is, plus structured content with the numbers behind it.

https://aurora-odds-mcp.pages.dev/mcp

Self-host it with npm run dev, or deploy the same file to Cloudflare. The visibility maths is a separate open-source library, aurora-sky.

{
  "mcpServers": {
    "aurora-odds": {
      "type": "http",
      "url": "https://aurora-odds-mcp.pages.dev/mcp"
    }
  }
}

Three questions people actually ask

Alerts say "G2" and "Kp 6". People want to know if it is worth putting their shoes on. Each tool answers one version of that question and nothing else.

check_aurora_now

The chance the aurora is bright enough for your eyes and for a phone camera in the next hour, whether it is dark, how cloudy it is, and which way and how high to look.

"Can I see the northern lights right now?"

plan_aurora_tonight

Hour by hour until dawn: darkness, expected activity and cloud, and the best window to go out.

"When should I go out tonight?"

explain_space_weather

What the solar wind is doing, the chance of a storm in the next hour, and the peak of NOAA's three-day outlook, in plain words.

"Is there a solar storm coming?"

How an answer is made

The wind on its way

Spacecraft at L1 measure the solar wind 30 to 60 minutes before it reaches Earth. NOAA publishes it every minute.

A forecast model

TabPFN, an open-weights foundation model, turns it into a probability for every activity level in the next hour. It reruns every ten minutes.

Your sky

Corrected magnetic latitude, how far the light is visible, how high the arc stands, when it gets dark, and how cloudy it is.

One sentence

The MCP tool returns a verdict worth saying out loud, and the numbers for anyone who wants them.