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io.github.physics-star-cat/databutler-facts

by physics-star-cat · remote · no sign-in to list tools · v1.0.0 · published by GitHub user physics-star-cat

Official thresholds, rates and fees by key, with source, verified date and signature.

Changes · 1
CompareRegistry entry

3 tools: 1 change things and 2 only read.

Scanned Oct 21, 2026

No check matched anything in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http databutler-facts https://databutler.dev/api/mcp/facts

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

3 tools

Changes things 1Claude Code: ask
  • what_changed_sinceWhat has changed in Data Butler's verified datasets since a date — pass your training-cutoff date to learn which UK tax/NI/benefit thresholds, exam-spec facts, official vehicle dat…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
    What has changed in Data Butler's verified datasets since a date — pass your training-cutoff date to learn which UK tax/NI/benefit thresholds, exam-spec facts, official vehicle datasets (UK DVSA, French RappelConso and Japanese MLIT recalls), software end-of-life dates (Node.js, Python, Ubuntu, Debian, Android, iOS, macOS, Windows, Java, Go, Ruby, PHP, PostgreSQL, React — cycles that reached end of life or whose dates moved), central-bank policy rates (Bank of England, Fed, ECB), US federal tax thresholds (IRS inflation adjustments, Social Security wage base, retirement and HSA limits), German tax and social-insurance thresholds (Grundfreibetrag, Beitragsbemessungsgrenzen, Zusatzbeitrag, Mindestlohn, Kindergeld), UK vehicle tax (VED) rates and MOT rules, UK exam dates (results days, summer timetable paper dates, entry deadlines and late-fee dates, announced specification changes), calendar facts (public holidays for the UK, US, Germany and France; tax-year and daylight-saving rules for nine countries — new years published, holidays added or moved) and UK government service fees and rules (passports, ETA, Universal Credit, eVisa) changed after your knowledge ends. Each entry: from → to, effectiveFrom, official source, verifiedDate, and a maintainer note (e.g. which Budget). Areas: uk-rates, uk-exams, vehicles, software-eol, policy-rates, us-rates, de-rates, uk-vehicle-rules, uk-exam-dates, calendar, uk-gov-process, or all. Coverage starts 2026-08-31. The same changelog is published for humans at https://databutler.dev/changes, with feeds at https://databutler.dev/changes.rss and https://databutler.dev/changes.atom. Output is a Verified Changes protocol document (verified-changes/0.1, spec https://databutler.dev/protocol); an entry whose figure is a Verified Fact carries factKey for get_fact.

    Annotations the server declares

    • title: What changed since
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
Only reads 2Claude Code: allow
  • get_factThe current value of one official figure by key — a tax threshold, rate, allowance, fee, deadline, limit or policy rate — with the date it was verified, the official source URL, th…No findings

    Why it is in this group

    • The name "get_fact" says "get": a word for reading.
    Description, as the server wrote it
    The current value of one official figure by key — a tax threshold, rate, allowance, fee, deadline, limit or policy rate — with the date it was verified, the official source URL, the period it applies to and a signature. Keys are `<country>/<topic>/<fact>`, e.g. `uk/income-tax/personal-allowance`, `uk/national-insurance/primary-threshold`, `us/social-security/wage-base`, `de/income-tax/grundfreibetrag`, `uk/bank-rate`, `eu/ecb/deposit-facility`, `uk/gov/passport-renewal-adult/fee-online-uk`. A loose key is resolved when unambiguous; otherwise the answer lists candidate keys. `max_age` (e.g. `30d`) marks the answer `stale` when the verification is older than that. Several keys separated by commas return a batch. Covers UK, US and German rates and thresholds, UK vehicle tax and MOT rules, UK government service fees, UK exam dates and central-bank policy rates; `coverage` lists the rest.

    Annotations the server declares

    • title: Get a verified fact
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • resolve_factRanked canonical fact keys for a plain-language question or a guessed key — "NI primary threshold", "ECB deposit rate", "passport renewal fee" — each with label, unit, period and v…No findings

    Why it is in this group

    • The name "resolve_fact" says "resolve": a word for reading.
    Description, as the server wrote it
    Ranked canonical fact keys for a plain-language question or a guessed key — "NI primary threshold", "ECB deposit rate", "passport renewal fee" — each with label, unit, period and verification date, and the full record of the top match when it is unambiguous. The keys feed `get_fact`. Filter by `namespace` (`uk`, `us`, `de`, `eu`).

    Annotations the server declares

    • title: Find the key for a fact
    • 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.

Install

Pinned to version 1.0.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http databutler-facts https://databutler.dev/api/mcp/facts

Run in a terminal.

Claude Code permissions

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

.claude/settings.json
{
  "permissions": {
    "allow": [
      "mcp__databutler-facts__get_fact",
      "mcp__databutler-facts__resolve_fact"
    ],
    "ask": [
      "mcp__databutler-facts__what_changed_since"
    ],
    "deny": []
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as databutler-facts. Review it before you use it.