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

io.github.physics-star-cat/databutler-taxphysics-star-catstreamable-httpv1.0.0Scanned 23 hours ago

Take-home pay after tax and social contributions for nine countries, with tax year.

1 tool: 1 do something that can't be undone.

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

Tools listed without sign-in. Remote posture

Anlyon alternative

1 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.

1 tool

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

take_home_payNet 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 cal…Reads text others write1 finding
Why it is in this group
- The name "take_home_pay" says "pay": a word that usually means money moves, which cannot be taken back.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
What it can reach
- untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
Findings
- Warn
  The server marks "take_home_pay" 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":true}; The name "take_home_pay" says "pay": a word that usually means money moves, which cannot be taken back.
  What this check looks for
Description, as the server wrote it
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. 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. Spain (es) is listed but answers covered:false because lifebynumbers.net computes it client-side only.
Annotations the server declares
- title: Take-home pay
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: true

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 or outbound.

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.; take_home_pay
Can send data out0: Can carry data to people or systems: it sends, posts or publishes, or takes a recipient, channel or URL.

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

Remote posture

What anyone on the internet sees at the remote endpoint: an anonymous initialize and tools/list, and the public OAuth metadata.

Tools listed without sign-in

Looked at Oct 22, 2026, 15:20 UTC, unchanged since Oct 22, 2026. No credentials were sent and no tool was called. What is looked at.

Reachable: yes
HTTP status of an anonymous initialize: 200
tools/list served without credentials: yes
Tools that change things, listed without credentials: 1
Protocol version: 2025-06-18
WWW-Authenticate on 401: not observed
resource_metadata in WWW-Authenticate: not observed
RFC 9728 protected resource metadata: not observed
Authorization servers: not observed
Legacy HTTP+SSE transport: no
Dynamic client registration: not observed
Client ID metadata documents: not observed

HighThe whole server
The endpoint served tools/list without credentials, and the list has 1 tool that changes things (1 irreversible). Whether a call also works without credentials was not tested: tools are never called.
Matched text
https://databutler.dev/api/mcp/tax: tools/list returned 1 tool to an anonymous client, including take_home_pay (irreversible)
What this check looks for

Findings

Matches of fixed checks, with the text they matched.

1 warn

Warntake_home_pay
The server marks "take_home_pay" 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":true}; The name "take_home_pay" says "pay": a word that usually means money moves, which 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 1.0.0. Values in angle brackets are yours to fill in.

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

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

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": [],
    "ask": [
      "mcp__databutler-tax__take_home_pay"
    ],
    "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 databutler-tax. Review it before you use it.

Capability tags behind 1 rule

mcp__databutler-tax__take_home_pay untrusted-input

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/io.github.physics-star-cat/databutler-tax/verify?hash=78527a59b7318d95f188cefcff24eea03eafe4c4298b895686c628979082b617" | jq -e '.changed == false'

Pinned hash 78527a59b731, from Oct 21, 2026, 19:34 UTC.

Watch

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

https://anlyon.dev/servers/io.github.physics-star-cat/databutler-tax/changes.xml

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Badge

[![anlyon.dev](https://anlyon.dev/badge/io.github.physics-star-cat/databutler-tax.svg)](https://anlyon.dev/servers/io.github.physics-star-cat/databutler-tax)

Source: MCP Registry · repository. Synced Oct 21, 2026, 18:43 UTC.