Skip to content
anlyon.devby Anlyon

PostCode Check

dev.workers.mike-tusa.postcodecheck/postcodecheckpostcodecheck.mike-tusa.workers.devstreamable-httpv0.1.0Scanned

Validate and normalize postal codes offline for 252 countries and territories. Format check only.

2 tools: 1 change things and 1 only read.

Tools: 0 delete, 0 irreversible, 1 write, 1 read.
  • Reads private data · 0
  • Reads text others write · 0
  • Can send data out · 0
  • 1 finding

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 →
Compare with similar serversMarkdownJSONReport this listing

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.

2 tools

Changes things 1Claude Code: ask
  • validate_postcodeCheck whether a postal code has a valid format for a country and return its normalized form (uppercase, official space or hyphen), a format example and the country name.1 finding

    Why it is in this group

    • The name "validate_postcode" says "validate": a word for reading.
    • The input takes a statement or command to run (input.code), which can change anything it can reach.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

    Findings

    • Warn

      The server marks "validate_postcode" 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 name "validate_postcode" says "validate": a word for reading.

      What this check looks for
    Description, as the server wrote it
    Check whether a postal code has a valid format for a country and return its normalized form (uppercase, official space or hyphen), a format example and the country name. Example: country "NL", code "1234ab" → valid true, normalized "1234 AB". Format check only (Google libaddressinput patterns): it does not confirm the code exists or is deliverable. Countries without postal codes return valid false with reason "no_postal_codes". Read-only. Same engine as GET /v1/validate.

    Annotations the server declares

    • title: Validate a postal code
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
Only reads 1Show 1 read-only tool
  • list_countriesList every supported country and territory with its ISO code, English name, whether it uses postal codes, a format example and the local name for the code (zip, eircode, PIN…).No findings

    Why it is in this group

    • The name "list_countries" says "list": a word for reading.
    Description, as the server wrote it
    List every supported country and territory with its ISO code, English name, whether it uses postal codes, a format example and the local name for the code (zip, eircode, PIN…). Read-only. Same data as GET /v1/countries.

    Annotations the server declares

    • title: List supported countries
    • 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 or untrusted-input or outbound.

Reads private data0
Reads files, mail, messages, databases, secrets, calendars or repositories.
Reads text others write0
Brings in text someone else can write: web pages, inbound email, messages, issues and comments.
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.

Findings

Matches of fixed checks, with the text they matched.

1 warn
  • Warnvalidate_postcode

    The server marks "validate_postcode" 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 name "validate_postcode" says "validate": a word for reading.

    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 0.1.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http postcodecheck https://postcodecheck.mike-tusa.workers.dev/mcp
claude mcp add --transport http postcodecheck https://postcodecheck.mike-tusa.workers.dev/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__postcodecheck__list_countries"
    ],
    "ask": [
      "mcp__postcodecheck__validate_postcode"
    ],
    "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 postcodecheck. Review it before you use it.

Pin

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/dev.workers.mike-tusa.postcodecheck/postcodecheck/verify?hash=eb559e86b47fbaa2fae2feedfd952e10ea13fa420d19d7f51494984ba7deb410" | jq -e '.changed == false'

Pinned hash eb559e86b47f, from Oct 26, 2026, 13:17 UTC.

Watch

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

https://anlyon.dev/servers/dev.workers.mike-tusa.postcodecheck/postcodecheck/changes.xml

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

Badge

anlyon.dev badge for dev.workers.mike-tusa.postcodecheck/postcodecheck
[![anlyon.dev](https://anlyon.dev/badge/dev.workers.mike-tusa.postcodecheck/postcodecheck.svg)](https://anlyon.dev/servers/dev.workers.mike-tusa.postcodecheck/postcodecheck)

Source: MCP Registry. Synced Oct 26, 2026, 13:17 UTC.