# jp-payroll-mcp

日本の給与計算・社会保険・労務のMCPサーバー。Japanese payroll, social insurance and labour law for AI assistants and HTTP clients: 47都道府県の保険料率、源泉徴収税額表、割増賃金、年次有給休暇、標準報酬月額の定時決定・随時改定、産休育休の保険料免除、最低賃金、消費税率。公表資料から計算し、根拠にした条文を必ず添えます。協会けんぽ・国税庁の公式表に一桁ずつ照合済み。社労士・人事労務の実務向け。

- **Type:** MCP server
- **Trust:** 60/100 (B), scored on the package rubric
- **Verification:** community-indexed — nobody has claimed this listing
- **Version:** 0.4.5
- **Author:** tsumugi
- **License:** MIT
- **npm:** jp-payroll-mcp
- **Endpoints:** streamable-http https://japan-payroll-api.tsumugi.workers.dev/mcp
- **Source:** https://github.com/kishida-devil/jp-payroll-mcp
- **Endpoint health:** reachable (last checked 2026-09-06T14:08:42.592Z, 1 sample) — uptime is not a security property and is not part of the trust score
- **Compatible clients:** claude-code, cursor, copilot, chatgpt, gemini (basis: transport)

## Trust

60/100 (B), scored on the package rubric
- Publisher verified: no
- Install scripts: nothing suspicious found
- Prompt-injection scan: not run
- Obfuscation scan: not run
- Evidence age: 0 days

## Security scan

- **Status:** clean
- **Scanned:** 2026-09-06T14:08:31.404Z
- **Version scanned:** 0.4.5
- **CVEs:** none found by OSV at scan time

## Tools

30 declared. Statically extracted from the shipped source — a floor on the surface, not a census.
- `calculate_payslip` — Full monthly deduction breakdown for one employee: health insurance, long-term care,
- `list_workers_compensation_rates` — Workers compensation (労災保険) rates by business type, and the employer premium on a
- `calculate_bonus` — Premiums and income tax on a 賞与. Both work differently from monthly pay and are
- `calculate_withholding_tax` — Income tax to withhold from a payment, from the National Tax Agency tables.
- `judge_monthly_revision` — Decides whether a pay change forces the standard remuneration to be revised, and answers
- `decide_regular_remuneration` — The yearly redetermination of standard remuneration, effective each September through the
- `judge_leave_end_revision` — A separate route with a lower bar than 随時改定, and the one people forget. ONE grade of
- `calculate_payroll_batch` — Runs calculate_payslip for many employees in one call and returns the run totals: gross,
- `decide_regular_remuneration_batch` — Runs the annual 定時決定 for a whole payroll in one call, and reports which employees moved
- `judge_annual_average` — For work whose April-June happens to be its busiest or quietest quarter, where the ordinary
- `lookup_standard_remuneration` — Maps a monthly amount to its health grade (1-50) and pension grade (1-32), with the
- `national_insurance` — For anyone outside employee cover: the self-employed, freelancers, people between jobs.
- `calculate_annual_cost` — What one employee costs an employer over a year, bonuses included.
- `judge_annual_leave` — Works out how many days of paid leave someone has been granted, and whether the employer
- `judge_worker_type` — Decides whether someone is covered by health and pension insurance, and on which
- `check_insurance_eligibility` — The single most expensive month-end mistake in Japanese payroll, and one an assistant will
- `check_leave_exemption` — Maternity and childcare leave look alike and behave differently. Maternity leave has no
- `get_age_milestones` — Returns the exact date each threshold is crossed and which premium starts or stops:
- `calculate_year_end_adjustment` — Year-end adjustment (年末調整) for 2026 from the National Tax Agency's 令和8年分 booklet: the
- `estimate_resident_tax` — Estimate of next fiscal year's resident tax (住民税: 道府県民税 + 市町村民税 + 森林環境税) from the
- `get_insurance_rates` — Health insurance, long-term care, pension and child-support rates for a prefecture, plus
- `get_minimum_wage` — Hourly 地域別最低賃金 for a prefecture. Revisions take effect prefecture by prefecture from
- `business_days` — Count business days in a range, shift a date by N business days, or check one date.
- `validate_invoice_numbers_batch` — Checks the National Tax Agency check digit on many qualified-invoice registration numbers
- `validate_corporate_number` — Checks the National Tax Agency check digit on a 13-digit 法人番号, or on a qualified
- `consumption_tax` — The consumption tax rate in force on a date, with the national and local parts, and the
- `get_statute_text` — Returns the full text of a Japanese statutory provision, as published by e-Gov.
- `calculate_overtime_pay` — Works out statutory premium pay under 労働基準法第37条 — overtime, night work and work on
- `commuting_allowance_exemption` — Works out how much of a commuting allowance escapes income tax, and states the amount
- `check_data_freshness` — Japanese statutory figures change on fixed dates — insurance rates each March, employment

## Install

**Verdict: review** — Installable, but 1 thing to check first: No publisher has proved control of this listing; it is indexed, not vouched for.
**Cautions** (coverage gaps and advisories — never blocking)
- No publisher has proved control of this listing; it is indexed, not vouched for.
**Config** (claude-code):
```json
"{\n  \"mcpServers\": {\n    \"jp-payroll\": {\n      \"command\": \"npx\",\n      \"args\": [\n        \"-y\",\n        \"jp-payroll-mcp\"\n      ]\n    }\n  }\n}"
```

## Blast radius

Contained to extensive — no credential declaration found, from the publisher, the upstream registry, or the README. Known so far: runs locally and hosted; read-only tool surface.
- Floor 17, ceiling 35 (tier: unknown)
- `unknown` means the floor and ceiling land in different bands — not measured enough to name one. It does not mean low.
- This is impact, not likelihood. A high radius is not a defect: a filesystem server is supposed to write files. It is never part of the trust score.

## Machine-readable views of this entry

- Signed JSON: https://forgeregistry.com/api/v1/packages/jp-payroll-mcp
- Install plan: https://forgeregistry.com/api/v1/packages/jp-payroll-mcp/install-plan
- Alternatives: https://forgeregistry.com/api/v1/alternatives/jp-payroll-mcp
- HTML page: https://forgeregistry.com/registry/jp-payroll-mcp
- MCP: POST https://forgeregistry.com/api/mcp → `forge_get_package` / `forge_install_plan`

## About this document

Generated by Forge (https://forgeregistry.com) — a compact rendering of the same record served, signed, at the JSON URL above. Trust and scan facts are the registry's own measurements; anything Forge did not measure is named as unmeasured rather than omitted.