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Japan Business Tools

Japanese holidays, business days, eras, postal codes, addresses and corporate numbers.

Connector by ossalt.jp · Domain verified by the MCP Registry

IndexedLicense unknownRemote (HTTP)
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Install

Works with Claude Code, VS Code, Cursor, Windsurf. Read the repository before you give any tool access to your data.

npx agentmarket install connector/ossalt-jp-jp-biz-tools

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://biz.ossalt.jp/mcp Remote (HTTP)

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About

Japanese holidays, business days, eras, postal codes, addresses and corporate numbers.

No reviews yet. Installed it? Reviews come from verified installers only. How reviews work

Permissions

What this server can do and what it asks for, from its tool list and install config. Checked Oct 25, 2026.

Tools
13 read · 0 write · 0 deleteRead-only
Secrets
None asked for
Install scripts
Nothing to install (hosted)
Runs as
Hosted (remote endpoint)

Tools by what they do 13

From the running server's own tool list (tools/list) on Oct 25, 2026.

Read 13 · Look things up without changing anything.

  • add_business_days
  • adjust_to_business_day
  • check_business_day
  • count_business_days
  • from_japanese_era
  • last_business_day_of_month
  • list_holidays
  • lookup_corporate_number
  • lookup_postal_code
  • normalize_address
  • search_corporation_by_name
  • search_postal_code
Show 1 more tools
  • to_japanese_era

Network hosts it talks to 1

  • biz.ossalt.jp · found in remote endpoint, install command

Tools (13)

As the server listed them on Oct 25, 2026. Descriptions are the server’s own words; hidden characters are shown as [U+…].

  • add_business_daysAdd business days / n営業日後・前read-only

    Return the date that is N business days after (or before, if N is negative) the given date. The start date itself is not counted; e.g. 1 business day after a Friday is the next Monday unless it is a holiday. / n営業日後(nが負なら前)の日付。起算日は数えない。

  • adjust_to_business_dayAdjust to a business day / 休みの日の前倒し・後ろ倒しread-only

    If the date is a business day, return it as is; otherwise move to the next ("next") or previous ("previous") business day. Useful for payment due dates that fall on holidays. / 営業日ならその日、休みなら次(next)または前(previous)の営業日。支払日が休みのときなどに使う。

  • check_business_dayCheck a business day / 営業日かどうかの判定read-only

    Check whether a date is a business day in Japan, and if not, why (weekend, holiday name, bank closure, or a custom closed day). `reason` is Japanese text; `reason_code` is one of weekend, holiday, bank_closure, extra_holiday (null on business days). flags: `estimated`/`unverified` when the year's holidays are an estimate. / その日が営業日かどうかと、休みの理由(土日・祝日の名前・銀行の休業日・指定された休日)。reason_code は weekend・holiday・bank_closure・extra_holiday。

  • count_business_daysCount business days / 期間の営業日数read-only

    Count business days from start to end, inclusive of both ends. Returns 0 if start is after end. The period can be up to 3,660 days (about 10 years). / start から end までの営業日の数(両端を含む)。start が end より後なら 0。期間は3,660日(約10年)まで。

  • from_japanese_eraConvert a Japanese era date (wareki) to a Gregorian date / 和暦から西暦read-only

    Convert a Japanese era date to YYYY-MM-DD. Accepts 令和8年10月7日, 令和元年5月1日, R8.10.7, H31/4/30, Reiwa 8.10.7, kanji numerals (昭和六十四年一月七日), a trailing weekday such as (水) or 水曜日, and full-width characters. `input_era`/`input_era_year` echo the input; `actual` is the correct era for that date. If the date is outside the input era (e.g. 平成31年5月1日, written after the era changed), it is still converted by counting years, `within_era` is false and flags has `outside_era`. If a weekday was given and does not match, `weekday_matches` is false and flags has `weekday_mismatch`. / 和暦の日付を西暦にする。元号の範囲の外(平成31年5月1…

  • last_business_day_of_monthLast business day of a month / 月末の最終営業日read-only

    Return the last business day of the given month. / その月の最終営業日。

  • list_holidaysList Japanese national holidays / 日本の祝日の一覧read-only

    List all Japanese national holidays and substitute holidays for a year, based on the National Holidays Act and verified against the Cabinet Office CSV. Each holiday has `name` (descriptive) and `official_name` (as written by the Cabinet Office). / その年の国民の祝日・休日(振替休日・国民の休日を含む)の一覧。name は内容がわかる名前、official_name は内閣府の表記。

  • lookup_corporate_numberLook up a Japanese corporate number / 法人番号から法人の情報read-only

    Look up a 13-digit Japanese corporate number (法人番号) in the National Tax Agency's monthly bulk data: name, furigana, English name, kind, registered address and postal code, assignment date, and closure (date, cause, successor) if the registry record was closed. The check digit (first digit) is verified first; a wrong check digit is reported as an input error. flags: `closed` (the registry record is closed — tell the user), `excluded_from_search`, `not_found`. This is not the invoice (qualified invoice issuer) registry. / 法人番号(13桁)から、名前・フリガナ・英語の名前・法人の種類・所在地・郵便番号・指定の日・閉鎖の日と事由・承継先を返す。国税庁の全件データ(月1回…

  • lookup_postal_codeLook up a Japanese postal code / 郵便番号から住所read-only

    Look up the address (prefecture, city, town) for a 7-digit Japanese postal code, from Japan Post data. Accepts forms like 1000001, 100-0001 or 〒100-0001. One code can cover several towns; all are returned. `town_detail` holds the parenthesized part as written by Japan Post (e.g. chome ranges or building floors). If the code is a business-specific code (大口事業所個別番号) or a PO box code, the business is returned in `offices`. / 郵便番号から住所(都道府県・市区町村・町域)。日本郵便のデータ。1つの郵便番号に町域が複数あれば、すべて返す。事業所の個別郵便番号なら、事業所名と所在地を offices に返す。

  • normalize_addressNormalize a Japanese address (to town level) / 住所の正規化(町域まで)read-only

    Split a Japanese address into prefecture, city, town and the rest (block numbers, building), matching Japan Post's address data, and return candidate postal codes. Absorbs full/half-width, spacing, kanji vs. arabic numerals, ヶ/ケ and omitted county names; fills in the prefecture when the city is unique. Does NOT verify block/house numbers and has no coordinates. `level` tells how far the match went: 0 = nothing matched, 1 = prefecture only (see `city_candidates` if the city name is ambiguous), 2 = city matched but not the town (`postal_codes` are city-wide candidates), 3 = town matched. `addres…

  • search_corporation_by_nameFind corporate numbers by name / 法人の名前から法人番号read-only

    Find Japanese corporations whose name starts with the given text (prefix match), in the National Tax Agency's monthly bulk data. Legal-form words such as 株式会社 or 一般社団法人 are ignored at either end, and full/half-width and spaces are normalized. Matching in the middle of a name and furigana search are not supported. flags: `truncated`, `exact_match_only` (too many names start with the input; only exact matches returned), `not_found`. Returns up to 100 matches (`total`, `returned`, `truncated`) with corporate number, name, prefecture, city and `is_closed` (registry record closed); use lookup_corpo…

  • search_postal_codeFind postal codes by address / 住所から郵便番号read-only

    Find Japanese postal codes by prefecture, city and (optionally) part of the town name, from Japan Post data. The city must be the full municipality name (e.g. 札幌市中央区, 新宿区); the county name may be omitted. With `office_name`, searches business-specific codes (大口事業所個別番号) of businesses in that city by name instead. Returns up to 100 matches. / 都道府県・市区町村・町域(部分一致、任意)から郵便番号を探す。市区町村は正式な名前で(郡名は省いてよい)。office_name を指定すると、その市区町村の事業所の個別郵便番号を事業所名(部分一致)で探す。

  • to_japanese_eraConvert a date to the Japanese era (wareki) / 西暦から和暦read-only

    Convert a Gregorian date (YYYY-MM-DD) to the Japanese era calendar, e.g. 2026-10-07 → 令和8年10月7日 (wareki_short R8.10.07, zero-padded). Year 1 is written 元年. Supported from 1873-01-01 (the Gregorian calendar was adopted on 明治6年1月1日). Eras: 令和 (R) from 2019-05-01, 平成 (H) from 1989-01-08, 昭和 (S) from 1926-12-25, 大正 (T) from 1912-07-30, 明治 (M) from 1868-01-25. flags: `assumes_current_era` for dates after today (the era might change). / 西暦の日付を和暦にする。1年目は「元年」。明治6年(1873年)1月1日から。今日より後の日付には assumes_current_era。

Signals

Last release
Oct 7, 2026 (24 days ago)

Details

Registry name
jp.ossalt/jp-biz-tools
Version
0.9.0
Auth
Auth not stated
License
License unknown
First seen
Oct 24, 2026
Last checked
Oct 24, 2026

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Japan Business Tools MCP server. Agent Mart. https://agentmart.dev/connectors/ossalt-jp-jp-biz-tools (last updated 2026-10-24)