groundhog.markets

markets.groundhog/weathergroundhog.marketsstreamable-httpv1.2.0Scanned 52 minutes ago

groundhog.markets: free weather forecasts in one call, plus Kalshi and Polymarket market rules.

8 tools: 1 do something that can't be undone, 4 change things and 3 only read.

Reads private data · 0
Reads text others write · 1
Can send data out · 1
2 findings

Anlyon alternative

5 of these tools change something. Run those as governed actions.

Declare what an action changes, and Anlyon puts it under a shared limit, binds every approval to the exact request, and grades the outcome. It works on any HTTPS API you can describe as an action.

Anlyon does not run, proxy or govern this MCP server. A tool your own code calls directly is not routed through Anlyon and is not governed by it.

Import an OpenAPI spec →

Tools

Grouped by what each tool does, most consequential first. Open one for its reasons and full description; descriptions are the publisher's own words.

8 tools

Can't be undone 1Sends, pays, publishes or merges: once done, it cannot be taken back.Claude Code: ask

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' d…Can send data out1 finding
Why it is in this group
- The input addresses people (input.to): what it sends cannot be taken back.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
What it can reach
- outboundThe input takes a destination (input.to): what the tool writes goes there.
Findings
- Warn
  The server marks "history" read-only (readOnlyHint: true), and its own name, description or input give the class "irreversible".
  Matched text
  annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}; The input addresses people (input.to): what it sends cannot be taken back.
  What this check looks for
Description, as the server wrote it
As-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) or obs (settlement truth: CLI, routine-METAR max/min). from/to (<= 366 days, 1 unit per 31 days); run=ISO | lead=N (+cycle=H: the run issued N days before) | asof=ISO (what was known then). Rows carry fetched_at and origin (bf:* = backfilled). TSV by default.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false

Changes things 4Creates or changes something that can be changed back.Claude Code: ask

forecastDaily high/low for any place from every free forecast: median, spread, rain, current obs and active alerts, with credits and the page URL.No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Description, as the server wrote it
Daily 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 the credits and link the page when you repeat numbers. size=runs: one place, each source's newest runs by day with run_utc and fetched_at; NBM adds XND, P12, Q12. variable=rain: members' share of 0.01 in or more and heavier (n = model families), NBM calibrated, amounts by source, so far today, month to date; rain line ≈647 tok, table ≈1,955.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
marketsWeather markets in a place (Kalshi, Polymarket high/low/rain): settlement station and rule, the number so far under that rule, our value and the official result once settled, forec…No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Description, as the server wrote it
Weather markets in a place (Kalshi, Polymarket high/low/rain): settlement station and rule, the number so far under that rule, our value and the official result once settled, forecast daily max/min at the station. No prices. Needs place or family. line ≈520 tok, table ≈1,757; every city ≈36,291. With neither: the list of market cities.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
receiptsHow often our settle value matched the venue's result, with every miss.No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Description, as the server wrote it
How often our settle value matched the venue's result, with every miss. No prices.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
sourcesOpen sources groundhog uses: licence, latest run, age, status.1 finding
Why it is in this group
- The description's first verb is "open": a word for a change.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Findings
- Warn
  The server marks "sources" read-only (readOnlyHint: true), and its own name, description or input give the class "write".
  Matched text
  annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}; The description's first verb is "open": a word for a change.
  What this check looks for
Description, as the server wrote it
Open sources groundhog uses: licence, latest run, age, status.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false

Only reads 3Looks things up and changes nothing.Show 3 read-only tools

fetchThe 7-day forecast of a place id from search: {id, title, text, url, metadata}.Reads text others writeNo findings
Why it is in this group
- The name "fetch" says "fetch": a word for reading.
What it can reach
- untrusted-inputThe description's first sentence says "url": it reads web pages, which anyone can write.
Description, as the server wrote it
The 7-day forecast of a place id from search: {id, title, text, url, metadata}. Keep the credits and link the url when you repeat numbers.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
placesFind a place slug by name, City, ST, airport code or lat,lon; says full blend or grid only.No findings
Why it is in this group
- The description's first verb is "find": a word for reading.
Description, as the server wrote it
Find a place slug by name, City, ST, airport code or lat,lon; says full blend or grid only.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
searchSearch places by name, City, ST, airport code or lat,lon.No findings
Why it is in this group
- The name "search" says "search": a word for reading.
Description, as the server wrote it
Search places by name, City, ST, airport code or lat,lon. Returns {results: [{id, title, url, text}]}; pass an id to fetch.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Exfil surface

Which tools read private data, which read text someone else can write, and which can send data out. One of each is a path a prompt injection can use.

No private-data, untrusted-input, outbound path in this server alone: no tool is tagged private-data.

Reads private data0: Reads files, mail, messages, databases, secrets, calendars or repositories.
Reads text others write1: Brings in text someone else can write: web pages, inbound email, messages, issues and comments.; fetch
Can send data out1: Can carry data to people or systems: it sends, posts or publishes, or takes a recipient, channel or URL.; history

Other servers in the same agent add their own tools to these paths. Audit your whole setup to see them together.

Findings

Matches of fixed checks, with the text they matched.

2 warn

Warnsources
The server marks "sources" read-only (readOnlyHint: true), and its own name, description or input give the class "write".
Matched text
annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}; The description's first verb is "open": a word for a change.
What this check looks for
Warnhistory
The server marks "history" read-only (readOnlyHint: true), and its own name, description or input give the class "irreversible".
Matched text
annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}; The input addresses people (input.to): what it sends cannot be taken back.
What this check looks for

History

Changes to its tool definitions and to its remote endpoint, newest first.

No change seen yet. Its tools are rescanned every day, and a remote endpoint is looked at once a week.

All changes to this server

Install

Pinned to version 1.2.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http weather https://groundhog.markets/mcp

claude mcp add --transport http weather https://groundhog.markets/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change or a way out, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json

{
  "permissions": {
    "allow": [
      "mcp__weather__places",
      "mcp__weather__search",
      "mcp__weather__fetch"
    ],
    "ask": [
      "mcp__weather__forecast",
      "mcp__weather__sources",
      "mcp__weather__markets",
      "mcp__weather__receipts",
      "mcp__weather__history"
    ],
    "deny": []
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. A read that can send data out (it takes a URL, say) asks first too. It assumes the server is installed as weather. Review it before you use it.

Capability tags behind 2 rules

mcp__weather__fetch untrusted-input
mcp__weather__history outbound

Keep the decision: fail CI when the tools change, follow every change, or show a badge.

Pin in CI

Fail a build when the tools you reviewed are not the tools the server serves today.

curl -s "https://anlyon.dev/api/v1/servers/markets.groundhog/weather/verify?hash=64e488acadf1c04a3e222ed5e060861353d63737baf7fde01efcfe3cb49f8d86" | jq -e '.changed == false'

Pinned hash 64e488acadf1, from Oct 28, 2026, 00:18 UTC.

Watch

Get told when its tools change: a new tool, a new description, a new class.

https://anlyon.dev/servers/markets.groundhog/weather/changes.xml

An Atom feed. Works in any feed reader or Slack's RSS app.

Badge

[![anlyon.dev](https://anlyon.dev/badge/markets.groundhog/weather.svg)](https://anlyon.dev/servers/markets.groundhog/weather)

Source: MCP Registry. Synced Oct 28, 2026, 00:17 UTC.