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

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

- Trust score: 81/100 (high trust)
- Change this week: +3
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- remote · `databutler.dev`: 81/100 (this document), [markdown](https://verifymcp.io/servers/physics-star-cat-databutler-facts/api-mcp-facts.md), [page](https://verifymcp.io/servers/physics-star-cat-databutler-facts/api-mcp-facts)

## Channel facts

- Endpoint: `https://databutler.dev/api/mcp/facts`
- 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 (good).
  - Context-footprint check failed: tool/resource definitions use about 1290 tokens (~430/item across 3 items; 3 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 77/100
  - Stability observed for 23 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **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**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 3 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 4 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-facts MCP server?

io.github.physics-star-cat/databutler-facts is a hosted endpoint at https://databutler.dev/api/mcp/facts, 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-facts 'https://databutler.dev/api/mcp/facts'
```

### Cursor

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

### VS Code

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

### Codex

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

### opencode

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

### OpenClaw

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

### Hermes

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

### Netclaw

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

### Vellum

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

### Other

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

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.

### 2026-11-05 (score 81, +1)

No change was recorded against any check on this day. Stability & Change Management went from 73 to 77. That category is still filling its 30-day observation window: 22 days of observed history at the previous scan, 23 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-11-02 (score 80, +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.

### 2026-11-01 (score 79, 0)

- [security] The server rewrote its instructions, which are the text every model session 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

### 2026-10-31 (score 79, +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.

### 2026-10-29 (score 78, +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.

### 2026-10-27 (score 77, +1)

No change was recorded against any check on this day. Stability & Change Management went from 43 to 47. That category is still filling its 30-day observation window: 13 days of observed history at the previous scan, 14 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-25 (score 76, 0)

- [security] Tool “what_changed_since” rewrote its description, which is the text the model reads

### 2026-10-24 (score 76, +1)

No change was recorded against any check on this day. Stability & Change Management went from 33 to 37. That category is still filling its 30-day observation window: 10 days of observed history at the previous scan, 11 at this one. The score rises as the window fills, whether or not the server changes.

## MCP tools (3)

### `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

### `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

## Diagnostics

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

## Score history

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

## Common questions

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

io.github.physics-star-cat/databutler-facts is an MCP server listed in the public MCP registry as io.github.physics-star-cat/databutler-facts. Official thresholds, rates and fees by key, with source, verified date and signature. This page covers its hosted endpoint (https://databutler.dev/api/mcp/facts).

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

io.github.physics-star-cat/databutler-facts scores 81 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-facts MCP server expose?

io.github.physics-star-cat/databutler-facts exposes 3 tools: get_fact, resolve_fact, what_changed_since. Their descriptions and schemas cost roughly 1,073 tokens of context every time the server is loaded.

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

No. We connected to io.github.physics-star-cat/databutler-facts 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-facts MCP server still maintained?

io.github.physics-star-cat/databutler-facts 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-facts MCP server?

VerifyMCP ran 13 checks on io.github.physics-star-cat/databutler-facts, 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/facts
- Repository: https://github.com/physics-star-cat/databutler
- Website: https://databutler.dev/api
- Changelog RSS feed: https://verifymcp.io/servers/physics-star-cat-databutler-facts/api-mcp-facts.xml
- Changelog JSON feed: https://verifymcp.io/servers/physics-star-cat-databutler-facts/api-mcp-facts/changelog.json
- Trust report (JSON): https://verifymcp.io/servers/physics-star-cat-databutler-facts/api-mcp-facts.json
- HTML version of this page: https://verifymcp.io/servers/physics-star-cat-databutler-facts/api-mcp-facts