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WeatherMCP serverFirst audited Nov 13, 2026

groundhog.markets

groundhog.markets: free weather forecasts in one call, plus Kalshi and Polymarket market rules.The vendor's description, from its MCP Registry listing.

Passed public checksAudited Nov 13, 2026

Every public check ran and passed. Public audit: we connect as an AI client would, list the tools and check what they say. We do not run them. How we audit

Does it work?
YesConnected in 198 ms.
Sign-up?
None neededIt answered without any account or key.
Can it change things?
No, read-onlyAll 9 tools say they only read.
Endpointhttps://groundhog.markets/mcp

Website Streamable HTTP · protocol 2025-11-25 · server version 1.2.0

What we checked, the evidence, and the tools it offers.

What we checked

Security

  • Passed: Connections are encrypted (HTTPS).

  • Passed: No hidden instructions found in tool text.

Safety labels

  • Passed: Every tool says whether it only reads or can change things.

Tools

  • Passed: 9 tools listed.

  • Passed: Every tool describes its inputs with a valid schema.

Protocol

  • Passed: The MCP handshake works (Streamable HTTP).

  • Passed: Protocol version 2025-11-25 (latest).

  • Passed: Unknown requests are refused.

Connection

  • Passed: The server responds.

Tools (9)

As the server describes them. The labels are the server's own: it says whether each tool only reads or can change things.

  • forecastDaily high/low for any place from every free forecast: median, spread, rain, current obs and active alerts, with credits and the page URL. line ≈321 tok, week ≈566, table ≈1,567, series ≈1,564. Keep…Read-only
  • placesFind a place slug by name, City, ST, airport code or lat,lon; says full blend or grid only. format=json also returns structuredContent; the JSON Schema is at https://groundhog.markets/api/v1/schema.j…Read-only
  • sourcesOpen sources groundhog uses: licence, latest run, age, status. format=json also returns structuredContent; the JSON Schema is at https://groundhog.markets/api/v1/schema.jsonRead-only
  • marketsKalshi and Polymarket weather markets (high, low, rain) in a place: settlement station and rule, the value so far under that rule, forecast daily max/min (or rain) at the station, our value and the o…Read-only
  • receiptsHow often our settle value matched the venue's result, with every miss. No prices. format=json also returns structuredContent; the JSON Schema is at https://groundhog.markets/api/v1/schema.jsonRead-only
  • coverageWhich Kalshi and Polymarket weather series groundhog tracks (key, family, kind, city, station, product), which it sees at the venue but does not support and why, and when each venue was last read. Th…Read-only
  • searchConnector form of places, for clients that only call search and fetch: places by name, City, ST, airport code or lat,lon as {results: [{id, title, url, text}]}; pass an id to fetch. Otherwise prefer…Read-only
  • fetchConnector form of forecast: the 7-day forecast of a place id from search as {id, title, text, url, metadata}. Otherwise prefer forecast, or markets for a market city. Keep the credits and link the ur…Read-only
  • historyAs-issued history for backtests (no look-ahead): kind=daily (every source's daily hi/lo/rain per run at a place), nbm (NBM text columns: TXN, XND, P12, Q12; view=day = the books' day view), obs (sett…Read-only

Audit history

  1. Nov 13Passed

What we sent

Every request in this audit, with the answer and how long it took. We never send credentials and never call a tool.

RequestAnswerTime
initializeHTTP 200198 ms
initializedHTTP 20286 ms
tools/listHTTP 20028 ms
unknown-methodHTTP 20023 ms

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