# io.github.physics-star-cat/databutler (remote · databutler.dev)

Verified facts for AI agents: rates, exams, recalls, holidays, and what changed since your cutoff.

- Trust score: 83/100 (high trust)
- Change this week: +3
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- remote · `databutler.dev`: 83/100 (this document), [markdown](https://verifymcp.io/servers/physics-star-cat-databutler/api-mcp.md), [page](https://verifymcp.io/servers/physics-star-cat-databutler/api-mcp)

## Channel facts

- Endpoint: `https://databutler.dev/api/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `1.0.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-11-05.

- **Endpoint Security**: 80/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - No authorisation is required to call this server. Nothing on it is marked destructive, but we can't show that an anonymous caller can only read: full credit needs the server to list at least one tool and every tool to be verifiably read-only. We use a best-effort check of tool names and descriptions to tell read-only tools from tools that change things, so some genuinely read-only tools may not get full credit. Names that start with a read verb (get, list, read, search and similar) and accurate readOnlyHint annotations help. Meet that to earn full credit, or require authorisation.
  - HTTPS is enforced; there's no plaintext access path.
  - The HSTS (Strict-Transport-Security) header is present.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 57/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 4573 tokens (~415/item across 11 items; 11 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 100/100
  - No destabilizing schema changes in the last 30 days.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
- **Tool Safety**: 75/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - 0 of 1 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation; "take_home_pay" implies "pay" and declares readOnlyHint instead, contradicting what its own name says it does.
  - An AI judge read all 12 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

## Install

### How do I install the io.github.physics-star-cat/databutler MCP server?

io.github.physics-star-cat/databutler is a hosted endpoint at https://databutler.dev/api/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http physics-star-cat-databutler 'https://databutler.dev/api/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "physics-star-cat-databutler": {
      "url": "https://databutler.dev/api/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "physics-star-cat-databutler": {
      "type": "http",
      "url": "https://databutler.dev/api/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.physics-star-cat-databutler]
url = "https://databutler.dev/api/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "physics-star-cat-databutler": {
      "type": "remote",
      "url": "https://databutler.dev/api/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add physics-star-cat-databutler --url 'https://databutler.dev/api/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  physics-star-cat-databutler:
    url: "https://databutler.dev/api/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "physics-star-cat-databutler": {
      "Transport": "http",
      "Url": "https://databutler.dev/api/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add physics-star-cat-databutler -t streamable-http -u 'https://databutler.dev/api/mcp'
```

### Other

```json
{
  "mcpServers": {
    "physics-star-cat-databutler": {
      "type": "http",
      "url": "https://databutler.dev/api/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-11-03 (score 83, +1)

- [security] Stability: 0.97 → pass

### 2026-11-01 (score 82, +1)

- [security] The server rewrote its instructions, which are the text every model session reads
- [security] Tool “call” rewrote its description, which is the text the model reads
- [security] Tool “catalogue” rewrote its description, which is the text the model reads
- [security] Tool “coverage” rewrote its description, which is the text the model reads
- [security] Tool “get_fact” rewrote its description, which is the text the model reads
- [security] Tool “what_changed_since” rewrote its description, which is the text the model reads
- [cosmetic] “coverage” reworded the description of “area”

### 2026-10-30 (score 81, +1)

No change was recorded against any check on this day. Stability & Change Management went from 83 to 87. That category is still filling its 30-day observation window: 25 days of observed history at the previous scan, 26 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-27 (score 80, +1)

- [security] The server rewrote its instructions, which are the text every model session reads
- [security] Tool “take_home_pay” rewrote its description, which is the text the model reads
- [cosmetic] “take_home_pay” reworded the description of “region”

### 2026-10-25 (score 79, 0)

- [security] The server rewrote its instructions, which are the text every model session reads
- [security] Tool “call” rewrote its description, which is the text the model reads
- [security] Tool “catalogue” rewrote its description, which is the text the model reads
- [security] Tool “coverage” rewrote its description, which is the text the model reads
- [security] Tool “what_changed_since” rewrote its description, which is the text the model reads
- [functional regression] Schema quality: 339 → 385
- [cosmetic] “coverage” reworded the description of “area”

### 2026-10-24 (score 79, +1)

No change was recorded against any check on this day. Stability & Change Management went from 63 to 67. That category is still filling its 30-day observation window: 19 days of observed history at the previous scan, 20 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-22 (score 78, +1)

No change was recorded against any check on this day. Stability & Change Management went from 57 to 60. That category is still filling its 30-day observation window: 17 days of observed history at the previous scan, 18 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-20 (score 77, +1)

No change was recorded against any check on this day. Stability & Change Management went from 50 to 53. That category is still filling its 30-day observation window: 15 days of observed history at the previous scan, 16 at this one. The score rises as the window fills, whether or not the server changes.

## MCP tools (11)

### `uk_rates_lookup` (~218 tokens)

UK rates lookup

Current UK (2026-27) rates and thresholds, verified against gov.uk with source URLs and verification dates. Categories: income-tax, national-insurance, minimum-wage, student-loans, vat, isa, state-pension, state-pension-age, stamp-duty, capital-gains, pensions, dividends, savings, marriage-allowance, statutory-sick-pay, statutory-parental-pay, child-benefit. Covers UK income tax, National Insurance, minimum wage, student loans, VAT, ISAs, pensions, stamp duty, capital gains, dividends, savings, the State Pension and State Pension age, statutory sick/maternity/paternity pay and Child Benefit.

Input parameters:

- `category` (string): one of: income-tax, national-insurance, minimum-wage, student-loans, vat, isa, state-pension, state-pension-age, stamp-duty, capital-gains, pensions, dividends, savings, marriage-allowance, statutory…

### `exam_topic_paper` (~191 tokens)

Exam topic → paper

Which exam paper is a topic on? The canonical student revision question ("is electricity paper 2 AQA?" — answer: no, Paper 1). Input a topic plus optional board/subject/level; returns the paper, sibling topics on that paper, spec code, and the official spec URL. Knows quirks like AQA Combined Science Trilogy Physics Paper 2 having no Space physics. Coverage: AQA GCSE Physics (8463); AQA GCSE Biology (8461); AQA GCSE Chemistry (8462); AQA GCSE Combined Science: Trilogy (8464); AQA GCSE Mathematics (8300).

Input parameters:

- `board` (string): e.g. aqa
- `level` (string): e.g. gcse
- `subject` (string): e.g. physics, combined science
- `topic` (string, required): e.g. electricity, forces, ecology, organic chemistry

### `domain_provenance` (~99 tokens)

Domain provenance

Who runs this domain? Live RDAP lookup: registration date and age, registrar, nameservers, status, whether the registrant is redacted, plus a typosquat check (edit-distance / brand-substring) against high-value brands. A very recently registered domain resembling a bank or big brand is a classic phishing signal — but report it as a signal, not a conclusion.

Input parameters:

- `domain` (string, required): e.g. example.com

### `package_provenance` (~104 tokens)

Package provenance

Who publishes this package, and is it a typosquat? Live npm or PyPI lookup: first-publish date and age, release count, latest version, maintainers/author, linked repo, plus a typosquat check against popular package names. Use when an agent is about to install or recommend an unfamiliar dependency.

Input parameters:

- `ecosystem` (string, required): npm or pypi
- `name` (string, required): package name, e.g. express or requests

### `take_home_pay` (~369 tokens)

Take-home pay

Net salary after income tax and social contributions for an employee in one of ten countries (uk, us, ca, au, in, br, pl, fr, de, es), computed live by the LifeByNumbers salary calculators (same operator). Takes a gross salary in local currency (annual by default, or monthly with period) and a country code, plus optional state and filingStatus for the US, province for Canada, region (england|scotland) for the UK and region (madrid|cataluna) for Spain. Returns gross, net and total deductions (each annual and monthly), a line-by-line breakdown typed as tax / social / contribution / repayment, effectiveRate, the tax year the figures apply to, currency, the assumptions behind the estimate and the upstream calculator page as source.

Input parameters:

- `country` (string, required): ISO 3166-1 alpha-2, lower case: uk, us, ca, au, in, br, pl, fr, de, es
- `filingStatus` (string): US only (default single)
- `gross` (number, required): gross salary in local currency, annual unless period is monthly, e.g. 50000
- `period` (string): period of gross (default annual); results always give both annual and monthly
- `province` (string): Canada only: two-letter province/territory code, e.g. BC (default ON)
- `region` (string): UK: england | scotland | wales | northern-ireland (scotland applies Scottish income tax bands; default england). Spain: madrid | cataluna, the autonomous community whose IRPF scale applies (default m…
- `state` (string): US only: two-letter state code, e.g. TX (default CA)

### `what_changed_since` (~573 tokens)

What changed since

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, Umsatzsteuer), 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), UK government service fees and rules (passports, ETA, Universal Credit, eVisa), Japanese vehicle statutory costs (車検 inspection fees, 自賠責 insurance rates), Japanese minimum wages by prefecture, 協会けんぽ health insurance rates, 雇用保険料率 and income-tax deductions, UK CPI and CPIH inflation rates (ONS, monthly) and US inflation (BLS CPI-U 12-month rate and index, each monthly release) 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, jp-vehicle-costs, jp-living-costs, uk-inflation, us-inflation, 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.…

Input parameters:

- `area` (string): default all
- `since` (string, required): ISO date YYYY-MM-DD, e.g. your training cutoff

### `get_fact` (~380 tokens)

Get a verified fact

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. `nextExpectedChange` is the next date the source's calendar allows the value to move; `status` is `stale` when that date has passed since verification. 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.

Input parameters:

- `as_of` (string): optional YYYY-MM-DD: the value in force that day
- `key` (string, required): one key, or several separated by commas (max 50), e.g. uk/income-tax/personal-allowance
- `max_age` (string): optional freshness bar: 30d, 12w, 6m, 1y or ISO 8601 (P30D)
- `period` (string): optional period label instead of as_of, e.g. 2025-26

### `resolve_fact` (~120 tokens)

Find the key for a fact

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`).

Input parameters:

- `limit` (integer): default 5
- `namespace` (string): optional jurisdiction filter
- `q` (string, required): question or guessed key

### `coverage` (~454 tokens)

Coverage

Exactly what Data Butler covers and does not, per area, including figures it does not serve yet. Areas: uk-rates, uk-exams, provenance, stats, vehicles, tax, software-eol, policy-rates, us-rates, de-rates, uk-vehicle-rules, uk-exam-dates, calendar, uk-gov-process, jp-vehicle-costs, jp-living-costs, uk-inflation, us-inflation (omit for all). Returns rate categories and tax years, boards/subjects, package ecosystems, stats operations, vehicle datasets, take-home-pay countries, the 14 software products with end-of-life data, central-bank policy rates (boe, fed, ecb), US federal rate categories and tax year, German rate categories and Veranlagungszeitraum, UK vehicle tax (VED) and MOT rule categories, UK exam dates (results, timetable, deadlines, spec-changes for jcq, aqa, pearson, ocr, wjec-eduqas; sqa results day), calendar facts: public holidays (uk, us, de, fr), tax years and daylight saving (uk, us, de, fr, au, in, ca, br, pl) for 2026–2028, UK government services (passports, DVLA, voting, registrations, Self Assessment, benefits, eVisa, ETA), Japanese vehicle statutory cost categories (weight tax, 自賠責, inspection fees, car taxes), Japanese daily-life figure categories (minimum wage, health insurance, pension, employment insurance, benefits, holidays, consumption tax, income tax, resident tax), UK inflation categories (cpi, cpih), US CPI-U inflation (latest month, prior month, annual averages), and an explicit notCovered list.

Input parameters:

- `area` (string): one of uk-rates, uk-exams, provenance, stats, vehicles, tax, software-eol, policy-rates, us-rates, de-rates, uk-vehicle-rules, uk-exam-dates, calendar, uk-gov-process, jp-vehicle-costs, jp-living-cos…

### `catalogue` (~472 tokens)

Tool catalogue

Every tool across all Data Butler servers (UK rates; UK exams; provenance; exact statistics; vehicles: UK MOT, UK, French and Japanese recalls; take-home pay for ten countries; software support status and end-of-life timelines for 14 runtimes and operating systems; central-bank policy rates: Bank of England, Fed, ECB; US federal rates and thresholds (us_rates_lookup: income tax, Social Security, Medicare, retirement, HSA, estate and gift, capital gains, IRMAA, RMD); German tax and social-insurance figures (de_rates_lookup: Einkommensteuertarif, Sozialversicherung, Mindestlohn, Minijob, Kindergeld, Kinderfreibetrag, Pauschbeträge, Entfernungspauschale, Umsatzsteuer); UK vehicle tax (VED) and MOT rules; UK exam dates and spec changes: results days, the summer 2027 timetable, entry deadlines, new specifications; calendar facts: public holidays, tax-year starts and daylight-saving switches for 2026–2028; UK government services: passport, driving licence, vehicle tax/SORN, voting, birth/death registration, Blue Badge, Self Assessment, NI number, Universal Credit, EU Settlement Scheme, eVisa, ETA; Japan vehicle statutory costs (jp_vehicle_costs_lookup: 自動車重量税, エコカー減税, 自賠責保険, 検査手数料, 自動車税, 軽自動車税); Japan daily-life official figures (jp_living_costs_lookup: 最低賃金, 健康保険料率, 年金, 雇用保険, 児童手当, 高額療養費, 祝日, 消費税, 基礎控除, 住民税); UK inflation: CPI and CPIH 12-month rates, CPI index and annual averages (ONS); US inflation (us_inflation_lookup: BLS CPI-U 12-month rate, index level, annual averages)), with input schemas — including tools not listed at this front door. Optional query filters by keyword. Run any of them with call, or connect to serverUrl directly.

Input parameters:

- `query` (string): keyword filter, e.g. regression, exam, npm

### `call` (~769 tokens)

Call any tool

Run any Data Butler tool by name — the long tail not listed here: exam_spec_lookup, exam_paper_index; exact statistics (distribution, hypothesis_test, confidence_interval, bayes_update, linear_regression, descriptive_stats); the vehicles hub (uk_mot_reliability, uk_recalls_for_model, uk_recalls_search, fr_recalls_for_model, fr_recalls_search, jp_recalls_for_model, jp_complaints_summary); software end-of-life (support_status {product, version}, support_timeline {product} for nodejs, python, ubuntu, debian, android, ios, macos, windows, oracle-jdk, go, ruby, php, postgresql, react); policy_rate (Bank of England Bank Rate, Fed federal funds target range, ECB key rates — committed data verified against the banks' own pages); us_rates_lookup (US federal rates and thresholds for the current tax year: income-tax, social-security, medicare, retirement, hsa, estate-gift, social-security-benefits, medicare-costs, capital-gains); de_rates_lookup (German tax and social-insurance figures for the current Veranlagungszeitraum: income-tax, social-insurance, minimum-wage, minijob, kindergeld, kinderfreibetrag, sparer-pauschbetrag, arbeitnehmer-pauschbetrag, entfernungspauschale, vat); uk_vehicle_rules_lookup (UK car tax: first-year CO2 bands, standard rate, expensive car supplement, 2001–2017 bands, pre-2001 rates, electric cars, historic vehicles; MOT due dates, fees, retests, penalties — verified against gov.uk); UK exam dates (uk_exam_dates {kind: results|timetable|deadlines|spec-changes, board?, qualification?}); calendar facts (calendar_facts {country, kind: holidays|tax-year|dst, year?, region?} and next_holiday {country, from?} — holidays for uk, us, de, fr; tax years and DST for uk, us, de, fr, au, in, ca, br, pl; 2026–2028); uk_gov_process (UK government services — passport and ETA fees, driving licence renewal, SORN, register to vote, birth/death registration, Self Assessment deadlines, NI number, Universal Credit, EU Settlement Scheme, eVisa — fees, processing times, sta…

Input parameters:

- `arguments` (object): that tool's arguments
- `tool` (string, required): tool name from catalogue

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/physics-star-cat-databutler/api-mcp#diagnostics

## Score history

- 2026-11-05: 83
- 2026-11-04: 83
- 2026-11-03: 83
- 2026-11-02: 82
- 2026-11-01: 82
- 2026-10-31: 81
- 2026-10-30: 81
- 2026-10-29: 80
- 2026-10-28: 80
- 2026-10-27: 80
- 2026-10-26: 79
- 2026-10-25: 79
- 2026-10-24: 79
- 2026-10-23: 78
- 2026-10-22: 78
- 2026-10-21: 77
- 2026-10-20: 77
- 2026-10-19: 76
- 2026-10-18: 76
- 2026-10-17: 75
- 2026-10-16: 75
- 2026-10-15: 75
- 2026-10-14: 74
- 2026-10-13: 74
- 2026-10-12: 73
- 2026-10-11: 73
- 2026-10-10: 72
- 2026-10-07: 71
- 2026-10-05: 70
- 2026-10-04: 70

## Common questions

### What is the io.github.physics-star-cat/databutler MCP server?

io.github.physics-star-cat/databutler is an MCP server listed in the public MCP registry as io.github.physics-star-cat/databutler. Verified facts for AI agents: rates, exams, recalls, holidays, and what changed since your cutoff. This page covers its hosted endpoint (https://databutler.dev/api/mcp).

### Is the io.github.physics-star-cat/databutler MCP server safe to use?

io.github.physics-star-cat/databutler scores 83 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the io.github.physics-star-cat/databutler MCP server expose?

io.github.physics-star-cat/databutler exposes 11 tools: uk_rates_lookup, exam_topic_paper, domain_provenance, package_provenance, take_home_pay, and 6 more. Their descriptions and schemas cost roughly 3,749 tokens of context every time the server is loaded.

### Does the io.github.physics-star-cat/databutler MCP server require authentication?

No. We connected to io.github.physics-star-cat/databutler without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the io.github.physics-star-cat/databutler MCP server still maintained?

io.github.physics-star-cat/databutler is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

### What did VerifyMCP test on the io.github.physics-star-cat/databutler MCP server?

VerifyMCP ran 13 checks on io.github.physics-star-cat/databutler, covering TLS certificate, Authorization, HTTPS, HSTS header and 9 more. Supply Chain Security and Provenance & Transparency do not apply to a hosted endpoint, so they were not tested. The score does not measure everything, and the scoring documentation lists what it leaves out.

## Links

- Remote endpoint: https://databutler.dev/api/mcp
- Repository: https://github.com/physics-star-cat/databutler
- Website: https://databutler.dev/api
- Changelog RSS feed: https://verifymcp.io/servers/physics-star-cat-databutler/api-mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/physics-star-cat-databutler/api-mcp/changelog.json
- Trust report (JSON): https://verifymcp.io/servers/physics-star-cat-databutler/api-mcp.json
- HTML version of this page: https://verifymcp.io/servers/physics-star-cat-databutler/api-mcp