# Japan Business Tools (remote · biz.ossalt.jp)

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

- Trust score: 83/100 (high trust)
- Change this week: +3
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- remote · `biz.ossalt.jp`: 83/100 (this document), [markdown](https://verifymcp.io/servers/jp-ossalt-jp-biz-tools/biz.md), [page](https://verifymcp.io/servers/jp-ossalt-jp-biz-tools/biz)

## Channel facts

- Endpoint: `https://biz.ossalt.jp/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `0.9.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-11-05.

- **Endpoint Security**: 74/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - No authorisation is required to call this server. Nothing on it is marked destructive, but we can't show that an anonymous caller can only read: full credit needs the server to list at least one tool and every tool to be verifiably read-only. We use a best-effort check of tool names and descriptions to tell read-only tools from tools that change things, so some genuinely read-only tools may not get full credit. Names that start with a read verb (get, list, read, search and similar) and accurate readOnlyHint annotations help. Meet that to earn full credit, or require authorisation.
  - HTTPS is enforced; there's no plaintext access path.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 65/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 3752 tokens (~288/item across 13 items; 13 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 97/100
  - Stability observed for 29 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 13 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 14 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

## Install

### How do I install the Japan Business Tools MCP server?

Japan Business Tools is a hosted endpoint at https://biz.ossalt.jp/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http jp-ossalt-jp-biz-tools 'https://biz.ossalt.jp/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "jp-ossalt-jp-biz-tools": {
      "url": "https://biz.ossalt.jp/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "jp-ossalt-jp-biz-tools": {
      "type": "http",
      "url": "https://biz.ossalt.jp/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.jp-ossalt-jp-biz-tools]
url = "https://biz.ossalt.jp/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "jp-ossalt-jp-biz-tools": {
      "type": "remote",
      "url": "https://biz.ossalt.jp/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add jp-ossalt-jp-biz-tools --url 'https://biz.ossalt.jp/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  jp-ossalt-jp-biz-tools:
    url: "https://biz.ossalt.jp/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "jp-ossalt-jp-biz-tools": {
      "Transport": "http",
      "Url": "https://biz.ossalt.jp/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add jp-ossalt-jp-biz-tools -t streamable-http -u 'https://biz.ossalt.jp/mcp'
```

### Other

```json
{
  "mcpServers": {
    "jp-ossalt-jp-biz-tools": {
      "type": "http",
      "url": "https://biz.ossalt.jp/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-11-05 (score 83, +1)

No change was recorded against any check on this day. Stability & Change Management went from 93 to 97. That category is still filling its 30-day observation window: 28 days of observed history at the previous scan, 29 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-11-03 (score 82, +1)

No change was recorded against any check on this day. Stability & Change Management went from 87 to 90. That category is still filling its 30-day observation window: 26 days of observed history at the previous scan, 27 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-31 (score 81, +1)

No change was recorded against any check on this day. Stability & Change Management went from 77 to 80. That category is still filling its 30-day observation window: 23 days of observed history at the previous scan, 24 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-29 (score 80, +1)

No change was recorded against any check on this day. Stability & Change Management went from 70 to 73. That category is still filling its 30-day observation window: 21 days of observed history at the previous scan, 22 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-27 (score 79, +1)

No change was recorded against any check on this day. Stability & Change Management went from 63 to 67. That category is still filling its 30-day observation window: 19 days of observed history at the previous scan, 20 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-25 (score 78, +1)

No change was recorded against any check on this day. Stability & Change Management went from 57 to 60. That category is still filling its 30-day observation window: 17 days of observed history at the previous scan, 18 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-23 (score 77, +1)

No change was recorded against any check on this day. Stability & Change Management went from 50 to 53. That category is still filling its 30-day observation window: 15 days of observed history at the previous scan, 16 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-21 (score 76, +1)

No change was recorded against any check on this day. Stability & Change Management went from 43 to 47. That category is still filling its 30-day observation window: 13 days of observed history at the previous scan, 14 at this one. The score rises as the window fills, whether or not the server changes.

## MCP tools (13)

### `list_holidays` (~122 tokens)

List Japanese national holidays / 日本の祝日の一覧

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。

Input parameters:

- `year` (integer, required): Year (1980-2099) / 年

### `check_business_day` (~282 tokens)

Check a business day / 営業日かどうかの判定

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。

Input parameters:

- `calendar` (string): "standard": weekends and national holidays are closed. "bank": also closed Dec 31 - Jan 3 (Japanese bank holidays). / standard：土日・祝日が休み。bank：加えて12月31日〜1月3日が休み（銀行の休業日）
- `date` (string, required): Date (YYYY-MM-DD) / 日付
- `extra_business_days` (array): Days treated as business days even if they are weekends or holidays. / 休日でも営業日とする日
- `extra_holidays` (array): Additional company-specific closed days (e.g. summer break). / 会社独自の休み

### `add_business_days` (~253 tokens)

Add business days / n営業日後・前

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。

Input parameters:

- `calendar` (string): "standard": weekends and national holidays are closed. "bank": also closed Dec 31 - Jan 3 (Japanese bank holidays). / standard：土日・祝日が休み。bank：加えて12月31日〜1月3日が休み（銀行の休業日）
- `date` (string, required): Start date (YYYY-MM-DD) / 起算日
- `days` (integer, required): Number of business days (negative = before) / 営業日の数（負なら前）
- `extra_business_days` (array): Days treated as business days even if they are weekends or holidays. / 休日でも営業日とする日
- `extra_holidays` (array): Additional company-specific closed days (e.g. summer break). / 会社独自の休み

### `count_business_days` (~255 tokens)

Count business days / 期間の営業日数

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。

Input parameters:

- `calendar` (string): "standard": weekends and national holidays are closed. "bank": also closed Dec 31 - Jan 3 (Japanese bank holidays). / standard：土日・祝日が休み。bank：加えて12月31日〜1月3日が休み（銀行の休業日）
- `end` (string, required): End date (YYYY-MM-DD) / 終了日
- `extra_business_days` (array): Days treated as business days even if they are weekends or holidays. / 休日でも営業日とする日
- `extra_holidays` (array): Additional company-specific closed days (e.g. summer break). / 会社独自の休み
- `start` (string, required): Start date (YYYY-MM-DD) / 開始日

### `adjust_to_business_day` (~252 tokens)

Adjust to a business day / 休みの日の前倒し・後ろ倒し

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。

Input parameters:

- `calendar` (string): "standard": weekends and national holidays are closed. "bank": also closed Dec 31 - Jan 3 (Japanese bank holidays). / standard：土日・祝日が休み。bank：加えて12月31日〜1月3日が休み（銀行の休業日）
- `date` (string, required): Date (YYYY-MM-DD) / 日付
- `direction` (string): next = 後ろ倒し, previous = 前倒し
- `extra_business_days` (array): Days treated as business days even if they are weekends or holidays. / 休日でも営業日とする日
- `extra_holidays` (array): Additional company-specific closed days (e.g. summer break). / 会社独自の休み

### `last_business_day_of_month` (~191 tokens)

Last business day of a month / 月末の最終営業日

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

Input parameters:

- `calendar` (string): "standard": weekends and national holidays are closed. "bank": also closed Dec 31 - Jan 3 (Japanese bank holidays). / standard：土日・祝日が休み。bank：加えて12月31日〜1月3日が休み（銀行の休業日）
- `extra_business_days` (array): Days treated as business days even if they are weekends or holidays. / 休日でも営業日とする日
- `extra_holidays` (array): Additional company-specific closed days (e.g. summer break). / 会社独自の休み
- `month` (integer, required): Month (1-12) / 月
- `year` (integer, required): Year (1980-2099) / 年

### `to_japanese_era` (~251 tokens)

Convert a date to the Japanese era (wareki) / 西暦から和暦

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。

Input parameters:

- `date` (string, required): Date (YYYY-MM-DD) / 日付

### `from_japanese_era` (~299 tokens)

Convert a Japanese era date (wareki) to a Gregorian date / 和暦から西暦

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日など）も年を数えて変換し、within_era が false・flags に outside_era。曜日が合わなければ weekday_mismatch。

Input parameters:

- `wareki` (string, required): Japanese era date, e.g. 令和8年10月7日 or R8.10.7 / 和暦の日付

### `lookup_postal_code` (~235 tokens)

Look up a Japanese postal code / 郵便番号から住所

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。

Input parameters:

- `postal_code` (string, required): 7-digit postal code, hyphen optional / 郵便番号（7桁、ハイフンは任意）

### `search_postal_code` (~295 tokens)

Find postal codes by address / 住所から郵便番号

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。

Input parameters:

- `city` (string, required): Municipality, e.g. 新宿区 / 市区町村
- `office_name` (string): Part of a business name, in kanji or katakana (optional) / 事業所名の一部（任意）
- `prefecture` (string): Prefecture, e.g. 東京都 (optional) / 都道府県（任意）
- `town` (string): Part of the town name, e.g. 西新宿 (optional) / 町域の一部（任意）

### `normalize_address` (~341 tokens)

Normalize a Japanese address (to town level) / 住所の正規化（町域まで）

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. `address` and `municipality_code` are null below level 2. flags: `partial` (level below 3), `ambiguous` (several city or postal code candidates — ask the user or show all). / 住所を都道府県・市区町村・町域・残り（番地・建物名など）に分け、郵便番号の候補を返す（日本郵便のデータにあてはめる）。番地が実在するかの確認と緯度・経度はない。level：0＝わからない、1＝都道府県まで、2＝市区町村まで（町域はわからない）、3＝町域まで。

Input parameters:

- `address` (string, required): Japanese address, e.g. 北海道札幌市中央区大通西10丁目1-1 / 住所

### `lookup_corporate_number` (~285 tokens)

Look up a Japanese corporate number / 法人番号から法人の情報

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）。先頭の1桁（チェックデジット）を確かめ、合わなければ入力の誤りとして返す。インボイス（適格請求書発行事業者）の登録の確認ではない。

Input parameters:

- `corporate_number` (string, required): 13-digit corporate number, hyphens/spaces allowed / 法人番号（13桁。ハイフン・空白は任意）

### `search_corporation_by_name` (~353 tokens)

Find corporate numbers by name / 法人の名前から法人番号

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_corporate_number for details. Corporations marked as excluded from search on the NTA site are not included. / 名前の先頭から合う法人を探す（前方一致）。株式会社などの言葉は前後どちらにあっても無視し、全角・半角や空白の違いも吸収する。名前の途中からの検索とフリガナの検索はできない。最大100件。詳しい情報は lookup_corporate_number で。国税庁のサイトで検索対象除外の法人は入っていない。

Input parameters:

- `name` (string, required): Beginning of the corporate name (e.g. トヨタ自動車) / 法人の名前の先頭（例：トヨタ自動車）
- `prefecture` (string): Prefecture to narrow down (optional, e.g. 東京都 or 東京) / 都道府県で絞り込む（任意）

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/jp-ossalt-jp-biz-tools/biz#diagnostics

## Score history

- 2026-11-05: 83
- 2026-11-04: 82
- 2026-11-03: 82
- 2026-11-02: 81
- 2026-11-01: 81
- 2026-10-31: 81
- 2026-10-30: 80
- 2026-10-29: 80
- 2026-10-28: 79
- 2026-10-27: 79
- 2026-10-26: 78
- 2026-10-25: 78
- 2026-10-24: 77
- 2026-10-23: 77
- 2026-10-22: 76
- 2026-10-21: 76
- 2026-10-20: 75
- 2026-10-19: 75
- 2026-10-18: 74
- 2026-10-17: 74
- 2026-10-16: 74
- 2026-10-15: 73
- 2026-10-14: 73
- 2026-10-13: 72
- 2026-10-12: 72
- 2026-10-11: 71
- 2026-10-10: 71
- 2026-10-09: 70
- 2026-10-07: 69

## Common questions

### What is the Japan Business Tools MCP server?

Japan Business Tools is an MCP server listed in the public MCP registry as jp.ossalt/jp-biz-tools. Japanese holidays, business days, eras, postal codes, addresses and corporate numbers. This page covers its hosted endpoint (https://biz.ossalt.jp/mcp).

### Is the Japan Business Tools MCP server safe to use?

Japan Business Tools scores 83 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the Japan Business Tools MCP server expose?

Japan Business Tools exposes 13 tools: list_holidays, check_business_day, add_business_days, count_business_days, adjust_to_business_day, and 8 more. Their descriptions and schemas cost roughly 3,414 tokens of context every time the server is loaded.

### Does the Japan Business Tools MCP server require authentication?

No. We connected to Japan Business Tools without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the Japan Business Tools MCP server still maintained?

Japan Business Tools is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

### What did VerifyMCP test on the Japan Business Tools MCP server?

VerifyMCP ran 13 checks on Japan Business Tools, covering TLS certificate, Authorization, HTTPS, HSTS header and 9 more. Supply Chain Security and Provenance & Transparency do not apply to a hosted endpoint, so they were not tested. The score does not measure everything, and the scoring documentation lists what it leaves out.

## Links

- Remote endpoint: https://biz.ossalt.jp/mcp
- Changelog RSS feed: https://verifymcp.io/servers/jp-ossalt-jp-biz-tools/biz.xml
- Changelog JSON feed: https://verifymcp.io/servers/jp-ossalt-jp-biz-tools/biz/changelog.json
- Trust report (JSON): https://verifymcp.io/servers/jp-ossalt-jp-biz-tools/biz.json
- HTML version of this page: https://verifymcp.io/servers/jp-ossalt-jp-biz-tools/biz