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NZ Data API

by nzdata.zakwins.workers.dev · remote · no sign-in to list tools · v1.1.0 · published by dev.workers.zakwins.nzdata

New Zealand public holidays, working-day deadlines, IRD/NZBN/bank checks, GST. Pay per call via x402

Changes · 3
CompareRegistry entry

8 tools: 3 change things and 5 only read.

Scanned Oct 21, 2026

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

claude mcp add --transport http nz-data-api https://nzdata.zakwins.workers.dev/mcp

Findings

Matches of fixed checks, with the text they matched.

1 warn
  • Warnnz_working_days_add

    The server marks "nz_working_days_add" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

    Matched text

    annotations: {"readOnlyHint":true,"openWorldHint":false}; The name "nz_working_days_add" says "add": a word for a change.

    What this check looks for

Tools

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

8 tools

Changes things 3Claude Code: ask
  • nz_gstNZ GST 15% calculator (exclusive or inclusive).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
    NZ GST 15% calculator (exclusive or inclusive). Paid tool: $0.001 USDC on Base per call via x402 (an unpaid call returns PaymentRequired; retry with _meta["x402/payment"]). Example args: {"amount":"115","mode":"inclusive"}

    Annotations the server declares

    • readOnlyHint: true
    • openWorldHint: false
  • nz_holidaysNZ public holidays 2022-2030 incl.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
    NZ public holidays 2022-2030 incl. Matariki, Mondayisation and optional regional anniversary day. Paid tool: $0.002 USDC on Base per call via x402 (an unpaid call returns PaymentRequired; retry with _meta["x402/payment"]). Example args: {"year":"2026","region":"auckland"}

    Annotations the server declares

    • readOnlyHint: true
    • openWorldHint: false
  • nz_working_days_addAdd N NZ working days to a date (e.g.1 finding

    Why it is in this group

    • The name "nz_working_days_add" says "add": a word for a change.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

    Findings

    • Warn

      The server marks "nz_working_days_add" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

      Matched text

      annotations: {"readOnlyHint":true,"openWorldHint":false}; The name "nz_working_days_add" says "add": a word for a change.

      What this check looks for
    Description, as the server wrote it
    Add N NZ working days to a date (e.g. OIA 20 working-day deadline). Paid tool: $0.002 USDC on Base per call via x402 (an unpaid call returns PaymentRequired; retry with _meta["x402/payment"]). Example args: {"start":"2026-12-15","days":"20","preset":"oia"}

    Annotations the server declares

    • readOnlyHint: true
    • openWorldHint: false
Only reads 5Claude Code: allow
  • nz_validate_bankValidate an NZ bank account number check digit (IRD algorithms A-G/X), normalise BB-bbbb-AAAAAAA-SSS and identify the bank code.No findings

    Why it is in this group

    • The name "nz_validate_bank" says "validate": a word for reading.
    Description, as the server wrote it
    Validate an NZ bank account number check digit (IRD algorithms A-G/X), normalise BB-bbbb-AAAAAAA-SSS and identify the bank code. Paid tool: $0.001 USDC on Base per call via x402 (an unpaid call returns PaymentRequired; retry with _meta["x402/payment"]). Example args: {"number":"01-0902-0068389-00"}

    Annotations the server declares

    • readOnlyHint: true
    • openWorldHint: false
  • nz_validate_irdValidate NZ IRD/GST number check digit.No findings

    Why it is in this group

    • The name "nz_validate_ird" says "validate": a word for reading.
    Description, as the server wrote it
    Validate NZ IRD/GST number check digit. Paid tool: $0.001 USDC on Base per call via x402 (an unpaid call returns PaymentRequired; retry with _meta["x402/payment"]). Example args: {"number":"49091850"}

    Annotations the server declares

    • readOnlyHint: true
    • openWorldHint: false
  • nz_validate_nzbnValidate NZBN (GTIN-13) check digit.No findings

    Why it is in this group

    • The name "nz_validate_nzbn" says "validate": a word for reading.
    Description, as the server wrote it
    Validate NZBN (GTIN-13) check digit. Paid tool: $0.001 USDC on Base per call via x402 (an unpaid call returns PaymentRequired; retry with _meta["x402/payment"]). Example args: {"number":"9429041535134"}

    Annotations the server declares

    • readOnlyHint: true
    • openWorldHint: false
  • nz_validate_phoneValidate and normalise an NZ phone number to E.164 with type.No findings

    Why it is in this group

    • The name "nz_validate_phone" says "validate": a word for reading.
    Description, as the server wrote it
    Validate and normalise an NZ phone number to E.164 with type. Paid tool: $0.001 USDC on Base per call via x402 (an unpaid call returns PaymentRequired; retry with _meta["x402/payment"]). Example args: {"number":"021 123 4567"}

    Annotations the server declares

    • readOnlyHint: true
    • openWorldHint: false
  • nz_working_daysCount NZ working days between two dates inclusive (weekends, public holidays, optional statutory Christmas shutdown presets oia|lgoima|building_act|rta).No findings

    Why it is in this group

    • The description's first verb is "count": a word for reading.
    Description, as the server wrote it
    Count NZ working days between two dates inclusive (weekends, public holidays, optional statutory Christmas shutdown presets oia|lgoima|building_act|rta). Paid tool: $0.002 USDC on Base per call via x402 (an unpaid call returns PaymentRequired; retry with _meta["x402/payment"]). Example args: {"start":"2026-10-01","end":"2026-10-31","region":"","preset":"none"}

    Annotations the server declares

    • readOnlyHint: 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 1.1.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http nz-data-api https://nzdata.zakwins.workers.dev/mcp

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__nz-data-api__nz_working_days",
      "mcp__nz-data-api__nz_validate_ird",
      "mcp__nz-data-api__nz_validate_nzbn",
      "mcp__nz-data-api__nz_validate_phone",
      "mcp__nz-data-api__nz_validate_bank"
    ],
    "ask": [
      "mcp__nz-data-api__nz_holidays",
      "mcp__nz-data-api__nz_working_days_add",
      "mcp__nz-data-api__nz_gst"
    ],
    "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 nz-data-api. Review it before you use it.