日本の給与・社会保険・労働法
Japan payroll & social insurance.
Connector by kishida-devil · GitHub account verified by the MCP Registry
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Works with Claude Code, VS Code, Codex, Cursor, Windsurf, Claude Desktop. Read the repository before you give any tool access to your data.
npx agentmarket install connector/kishida-devil-jp-payroll-mcp
Asks which of your tools to add it to (Claude Code, Codex, Cursor, VS Code, Windsurf, Gemini CLI, Claude Desktop) and shows the change first. See https://agentmart.dev/cli.
Remote endpoint
https://japan-payroll-api.tsumugi.workers.dev/mcpRemote (HTTP)
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What this server can do and what it asks for, from its tool list, install config and code. Checked Nov 1, 2026.
- Tools
- 19 read · 2 write · 0 delete · 9 not yet classified
- Secrets
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- Node.js package
Tools by what they do 30
From the running server's own tool list (tools/list) on Oct 25, 2026.
Read 19 · Look things up without changing anything.
business_dayscalculate_annual_costcalculate_bonuscalculate_overtime_paycalculate_payslipcalculate_withholding_taxcalculate_year_end_adjustmentcheck_data_freshnesscheck_insurance_eligibilitycheck_leave_exemptionestimate_resident_taxget_age_milestones
Show 7 more tools
get_insurance_ratesget_minimum_wageget_statute_textlist_workers_compensation_rateslookup_standard_remunerationvalidate_corporate_numbervalidate_invoice_numbers_batch
Write 2 · Create, change, send or run things.
decide_regular_remuneration_batchjudge_worker_type
Not yet classified 9 · We could not tell from the name and description.
calculate_payroll_batchcommuting_allowance_exemptionconsumption_taxdecide_regular_remunerationjudge_annual_averagejudge_annual_leavejudge_leave_end_revisionjudge_monthly_revisionnational_insurance
Network hosts it talks to 26
api.github.com· found in codecity.kobe.lg.jp· found in codecity.nagoya.jp· found in codecity.yokohama.lg.jp· found in codedash.cloudflare.com· found in codedigital.go.jp· found in codediscord.com· found in codegithub.com· found in codehoujin-bangou.nta.go.jp· found in codeinvoice-kohyo.nta.go.jp· found in codejapan-payroll-api.tsumugi.workers.dev· found in remote endpoint, install command, codekyoukaikenpo.or.jp· found in codelaws.e-gov.go.jp· found in codemhlw.go.jp· found in codenenkin.go.jp· found in codenta.go.jp· found in codepref.kanagawa.jp· found in codepref.miyagi.jp· found in codeqiita.com· found in coderapidapi.com· found in codesitemaps.org· found in codesmithery.ai· found in codesoumu.go.jp· found in codeweb.pref.hyogo.lg.jp· found in codewww8.cao.go.jp· found in codezenn.dev· found in code
Tools (30)
As the server listed them on Oct 25, 2026. Descriptions are the server’s own words; hidden characters are shown as [U+…].
business_days祝日・営業日計算(銀行カレンダー対応)Count business days in a range, shift a date by N business days, or check one date. Covers 1955-2027 including substitute holidays, 国民の休日 (a weekday that is a holiday only because it sits between two others) and one-off imperial events, so the awkward years are right and not only the tidy ones. Set calendar to "bank" for the statutory banking calendar (銀行法施行令第5条), which is also closed 31 December to 3 January — relevant for payment due dates.
calculate_annual_cost年間の労務コスト — 賞与の上限を年度で通した額What one employee costs an employer over a year, bonuses included. Reach for this rather than multiplying a payslip by twelve, because the two do not agree once a bonus is paid. 健康保険法第45条 caps the standard bonus cumulatively across the year — 5,730,000 from 1 April to 31 March — so the same bonus costs a different amount depending on where it falls, and once the year is used up later bonuses carry no health premium. 厚生年金保険法第24条の4 caps at 1,500,000 per payment with no yearly total, so pension keeps charging where health has stopped. Pass bonuses in the order they are paid: the health allowanc…
calculate_bonus賞与の社会保険料と源泉所得税Premiums and income tax on a 賞与. Both work differently from monthly pay and are routinely got wrong. Premiums are charged on 標準賞与額 (the bonus truncated to the thousand yen) under two caps that behave differently: health, long-term care and child support cap at 5,730,000 yen CUMULATIVELY across the fiscal year from 1 April, while pension caps at 1,500,000 yen PER PAYMENT. The annual cap cannot be applied without fiscal_year_to_date, so pass it whenever an earlier bonus was paid in the same fiscal year. Withholding tax on a bonus is derived from the PREVIOUS month's pay, not from the bonus its…
calculate_overtime_pay割増賃金(時間外・深夜・休日)の計算Works out statutory premium pay under 労働基準法第37条 — overtime, night work and work on a statutory holiday. The rates do not simply add up, and getting this wrong under-pays wages. A night premium stacks on top: overtime at night is 1.25 + 0.25 = 1.5, holiday work at night is 1.35 + 0.25 = 1.6. But a statutory holiday carries no overtime premium at all — a day with no duty to work has nothing to exceed — so holiday hours are 1.35, never 1.6 by adding overtime. Overtime beyond sixty hours in a month is 50%, and the deferral that exempted small employers ended on 1 April 2023, so headcount no longe…
calculate_payroll_batch給与計算をまとめて — 事業所全員分と合計Runs calculate_payslip for many employees in one call and returns the run totals: gross, employee deductions, net, and employer cost. Reach for this the moment more than two or three people are in play. A monthly payroll is not a sequence of unrelated questions — the employer share, the totals and the run id only mean anything across the whole run. Asking one employee at a time gives no total and no way to tell a retry from a second run. Put anything shared in defaults (prefecture, business_type, column) and let each row carry only what differs, which is usually pay and age. A row that canno…
calculate_payslip給与計算 — 社会保険料・源泉所得税・手取りFull monthly deduction breakdown for one employee: health insurance, long-term care, pension, child support, employment insurance, withholding income tax and net pay, with the employer share as well. Use this rather than computing it yourself. Premiums are charged on 標準報酬月額 — a 50-grade step function — and not on actual salary, while employment insurance IS charged on actual salary; the employee share rounds half DOWN; pension stops at grade 32; long-term care applies only from 40 to 64. Income tax is computed on pay after social insurance, which the tool derives internally, so do not pre-ded…
calculate_withholding_tax源泉徴収税額(月額表・日額表・電算機計算の特例)Income tax to withhold from a payment, from the National Tax Agency tables. The taxable amount is pay AFTER social insurance has been deducted, not gross. Pick the table with `period`: "monthly" for 月額表, "daily" for 日額表. The daily table has a third column, 丙, which applies to work engaged by the day and takes no dependant adjustment at all. Use `method: "computer"` for the 電算機計算の特例 formula, which payroll software may use instead of the table and can differ by a few yen.
calculate_year_end_adjustment年末調整(令和8年分)Year-end adjustment (年末調整) for 2026 from the National Tax Agency's 令和8年分 booklet: the printed 給与所得控除後の給与等の金額 table (1,103 rows), the income-adjustment deduction, social/life/earthquake insurance deductions, spouse, specified-relative (19-22 with income), dependant, disability, widow/single-parent/student and basic deductions, the year-end tax bracket table, the housing-loan credit and the 2.1% reconstruction surtax. Returns every box of the 源泉徴収簿 (⑦ to ㉗) and whether the difference is a refund or a collection. Pay figures are for the whole calendar year, bonuses included. Pass only what the e…
check_data_freshnessデータ鮮度 — 各データの対象期間と次回改定Japanese statutory figures change on fixed dates — insurance rates each March, employment insurance each April, minimum wage each October — and a stale table produces numbers that look plausible and are wrong. This reports what every dataset currently covers and when its next revision is due. Worth calling before relying on a figure for a filing, and whenever a result is being checked against a date near one of those boundaries.
check_insurance_eligibility入社月・退社月の保険料の要否The single most expensive month-end mistake in Japanese payroll, and one an assistant will get wrong from memory. Coverage ends the day AFTER the last day worked, not on it. So an employee leaving on the LAST day of a month loses coverage on the 1st of the next month, and still owes that month's premium — while leaving one day earlier means no premium for the month at all. A full month of both employee and employer premium turns on a single day. Always check here rather than reasoning it out.
check_leave_exemption産休・育休の保険料免除月Maternity and childcare leave look alike and behave differently. Maternity leave has no day-count test and exempts bonus premiums unconditionally; childcare leave gained a 14-day rule in October 2022 and exempts bonus premiums only when the leave exceeds one month. Two results catch people out and are worth checking rather than assuming: a leave that starts and ends inside one month exempts nothing by itself under the main rule, while a SINGLE day of leave on the last day of a month is exempt. Employment insurance is never exempt — it is charged on wages actually paid.
commuting_allowance_exemption通勤手当の非課税限度額Works out how much of a commuting allowance escapes income tax, and states the amount that still counts as remuneration for social insurance. These are two different bases, and that asymmetry is the part people get wrong. Social insurance counts a commuting allowance in full — it is 報酬 under 健康保険法第3条第5項 regardless of the tax treatment — while income tax is charged only on what exceeds the ceiling. So a 15,000 yen allowance on a 300,000 yen salary makes the standard-remuneration basis 315,000 and the taxable pay 300,000. Never answer with a single figure that is meant to serve both. The ceili…
consumption_tax消費税率(日付指定・軽減税率・改定履歴)The consumption tax rate in force on a date, with the national and local parts, and the reduced 8% rate for food and newspapers. Pass amount to have the tax worked out. Japan changed the rate four times since 1989 (3% → 5% → 8% → 10%), and the reduced rate has existed only since 2019-10-01. A back-dated invoice or a credit note against an old sale is charged at the rate of the original transaction, not today's, so the date matters more often than people expect. Set history to see every change with its statute.
decide_regular_remuneration定時決定(算定基礎届) — 4〜6月の報酬からThe yearly redetermination of standard remuneration, effective each September through the following August. Months below the payment-basis-day threshold drop OUT of the average entirely — they are not counted as zero, which is the usual mistake. If no month qualifies, the previous grade carries over by 保険者算定, except for 短時間就労者, who have an intermediate step at 15 days that exists nowhere else in the scheme and not in 随時改定. Pass acquired_month to also learn how long a 資格取得時決定 stays in force.
decide_regular_remuneration_batch定時決定(算定基礎届)をまとめて — 事業所全員分Runs the annual 定時決定 for a whole payroll in one call, and reports which employees moved grade. 健康保険法第41条 puts every insured employee on the same schedule — the average of April, May and June pay, over the months with at least seventeen payment-basis days, applied from September to the following August. So June is the one month of the year when an office decides its entire payroll at once, and asking about one employee at a time is the wrong shape for the task. Reach for this the moment more than a couple of employees are in play. Each row returns the same judgement as decide_regular_remunera…
Show 15 more tools
estimate_resident_tax個人住民税の見込み額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 previous year's income and the municipality: employment income from the NTA table for that year, resident-tax deductions (basic 430,000, spouse 330,000, dependants 330,000/450,000/380,000, life insurance capped at 70,000), the 10% income levy split 4%/6% (2%/8% in designated cities), the adjustment credit, the non-taxable thresholds (35万円 × persons + 10万円 + 21万円, with the 級地 rate), ふるさと納税 basic and special credits (special capped at 20% of the income levy), the housing-loan carry-over, per-capita amounts includin…
get_age_milestones年齢到達日(40/65/70/75)と保険料の変化Returns the exact date each threshold is crossed and which premium starts or stops: long-term care begins at 40 and ends at 65, pension ends at 70, health insurance ends at 75 (transfer to 後期高齢者医療). Compute this here rather than by subtracting years. Under 年齢計算ニ関スル法律 an age is reached the day BEFORE the birthday, so someone born on the 1st of a month attains it in the previous month and their premium changes a month earlier than expected.
get_insurance_rates社会保険料率・雇用保険料率Health insurance, long-term care, pension and child-support rates for a prefecture, plus the bonus caps and the employer-only child-care contribution. Health rates differ by prefecture and change each March; pension is national. Add business_type for the employment insurance rates, which change each April — pass as_of to get the rate in force on that date (FY2025 and FY2026 are held; March is the month where health rates are already the new year's while employment insurance is still the old year's).
get_minimum_wage最低賃金(指定日時点)Hourly 地域別最低賃金 for a prefecture. Revisions take effect prefecture by prefecture from October, on different days, so a date matters — pass one when checking a past payroll rather than assuming the current rate applied. History runs back to FY2002.
get_statute_text条文の本文を取得Returns the full text of a Japanese statutory provision, as published by e-Gov. The judgement tools name the statute or notice their answer rests on, but not its words. Use this to quote the provision itself — a citation the reader can check beats a citation they have to take on trust, and Japanese payroll advice is routinely wrong in ways that only reading the article reveals. Only the provisions this API cites are bundled (about 28 across 8 laws); call it with no ref to list them. Abbreviations as practitioners write them (健保法43条, 厚年法81条の2, 徴収法11条), a missing 第, and paragraph-level referen…
judge_annual_average年間平均による保険者算定(季節変動がある場合)For work whose April-June happens to be its busiest or quietest quarter, where the ordinary calculation would fix a grade that is wrong for eleven months of the year. Available for 定時決定 (since April 2011) and 随時改定 (since October 2018). The 随時改定 figure is NOT a plain twelve-month average: it is the three-month average of FIXED pay plus the twelve-month average of NON-FIXED pay, so the two are supplied separately, and three distinct grade tests must all pass. Both routes need the employee's consent and require that the swing recurs every year for reasons inherent to the work — a one-off busy p…
judge_annual_leave年次有給休暇 — 付与日数と年5日の時季指定義務Works out how many days of paid leave someone has been granted, and whether the employer still owes the five days it must direct. 労働基準法第39条 grants ten working days once six months of service are complete and attendance reaches eighty per cent of all working days, then adds one, two, four, six, eight and ten days in the years that follow. The ceiling everyone quotes as twenty is not in the article: it is the ten of the first grant plus the ten added from the sixth year. Someone under thirty hours a week working four days or fewer takes a smaller table from 施行規則第24条の3. Thirty hours is where it…
judge_leave_end_revision産休・育休終了時改定(1等級差で改定)A separate route with a lower bar than 随時改定, and the one people forget. ONE grade of movement is enough, and fixed pay need not have changed at all — which matters because returning to shorter hours usually cuts pay without changing any rate, so 随時改定 would not fire and the employee would keep overpaying on their pre-leave grade. Only one of the three months has to reach the day threshold, and months that miss it are excluded from the average. The employee must apply; an employer cannot file it alone. It is unavailable if another leave begins the day after this one ends.
judge_monthly_revision随時改定(月額変更届)の要否判定Decides whether a pay change forces the standard remuneration to be revised, and answers SEPARATELY for health insurance and pension — the tables differ, so a change routinely moves one and not the other. Above roughly 665,000 yen the pension table is exhausted, so a large raise for a well-paid employee moves several health grades and no pension grade. Do not try to reason this out unaided. Neither the "two grades or more" test nor the requirement that FIXED pay changed appears anywhere in 健康保険法 or its regulations — both come from 昭和36年 保発第4号, a ministerial notice, along with four exceptions …
judge_worker_type被保険者区分の判定 — 四分の三基準と20時間・88,000円・学生・51人Decides whether someone is covered by health and pension insurance, and on which payment-basis day count their annual determination runs. Call this before decide_regular_remuneration or judge_monthly_revision whenever the person is anything other than plainly full-time. Those tools take a worker_type, and guessing it changes a real number: the determination counts months of seventeen payment-basis days for an ordinary employee and eleven for a 短時間労働者. Get the classification wrong and the answer is wrong with no sign of it. 健康保険法第3条第1項第9号 covers anyone whose weekly hours and monthly days reac…
list_workers_compensation_rates労災保険率 — 事業の種類別Workers compensation (労災保険) rates by business type, and the employer premium on a given 賃金総額. The whole premium falls on the employer — nothing is deducted from the employee, unlike every other statutory premium. Rates run from 2.5/1000 to 88/1000 depending on the industry, a 35-fold spread, so this cannot be estimated. Pass the 事業の種類の番号 from the 労働保険関係成立届; omit it to get the whole table.
lookup_standard_remuneration標準報酬月額の等級照会Maps a monthly amount to its health grade (1-50) and pension grade (1-32), with the standard remuneration each resolves to and whether the pension grade was clamped. Use it to check a grade, not to compute premiums — calculate_payslip does that.
national_insurance国民年金・国民健康保険 — 被用者保険に入らない人の側For anyone outside employee cover: the self-employed, freelancers, people between jobs. Use this instead of calculate_payslip when the person is not an employee. Running a freelancer through the payslip returns a figure computed under a different scheme entirely, with nothing in the answer to say so. If you are unsure which side someone is on, judge_worker_type decides it. The two schemes differ in how far they can be answered, and the difference matters. 国民年金法第87条 makes the pension contribution a statutory amount times a revision rate set each year by cabinet order — the same figure everywh…
validate_corporate_number法人番号・インボイス登録番号の検証Checks the National Tax Agency check digit on a 13-digit 法人番号, or on a qualified invoice registration number (the same 13 digits prefixed with T). This proves the number is well formed. It does NOT prove the number is registered, and it does not identify the holder: sole proprietors receive invoice numbers that satisfy exactly the same rule, so a passing check digit must not be reported as evidence of a corporation. To confirm registration, use the National Tax Agency's own lookup.
validate_invoice_numbers_batchインボイス登録番号をまとめて形式検査Checks the National Tax Agency check digit on many qualified-invoice registration numbers in one call. Be careful how you report the result. A passing check digit means the shape of the number is right and nothing more. 消費税法第57条の2 provides both for the Commissioner to revoke a registration and for one to lapse, so a well-formed number can be unregistered, revoked or expired. Never tell someone a number is valid, verified or confirmed on the strength of this — say the format checks out, and that the register itself was not consulted. What it does earn is elimination. Anything failing on shape…
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- Last commit
- Sep 3, 2026 (2 months ago)
- Last release
- Sep 3, 2026 (2 months ago)
From GitHub (fetched Oct 24, 2026).
Details
- Registry name
io.github.kishida-devil/jp-payroll-mcp- Version
- 0.4.5
- Auth
- Auth not stated
- Packages
- npm jp-payroll-mcp
- License
- MIT
- Repository
- github.com/kishida-devil/jp-payroll-mcp
- First seen
- Oct 24, 2026
- Last checked
- Oct 24, 2026
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日本の給与・社会保険・労働法 MCP server. Agent Mart. https://agentmart.dev/connectors/kishida-devil-jp-payroll-mcp (last updated 2026-10-24)