# OIYO Korea Calculators

> Korean personal tax, payroll, labor, real estate and calendar calculators. Code, no LLM.

- name: io.github.yuli3/oiyo-calculations
- version: 1.3.3
- connection class: R0 (autonomous)
- trust: 95/100
- quality: 94/100 (new)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/io.github.yuli3%2Foiyo-calculations
- tools: https://api.protogrid.dev/v1/servers/io.github.yuli3%2Foiyo-calculations/tools

**An agent can connect right now, no human step.** Remote endpoint, no authentication, reachable on the last probe.

## Connection (mcpServers)

```json
{
  "mcpServers": {
    "oiyo-calculations": {
      "type": "http",
      "url": "https://api-oiyo.861106.workers.dev/mcp"
    }
  }
}
```


## Trust

- hygiene: 100
- liveness: 94
- freshness: 100
- provenance: 90
- drivers: +repository +namespace-matches-repo +website +reachable +uptime-86% +updated-2d-ago
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 94/100 (new)

### protocol: 88 (weight 25)

- pass `protocol.modern`: supports 2026-07-28 (server/discover)
- pass `protocol.stateless`: answers without a session
- pass `protocol.transport`: streamable HTTP
- warn `protocol.list_ttl`: tools/list declares ttlMs 0, so clients re-fetch it on every use

### authorization: n/a (weight 15)

- n/a `auth.prm`, `auth.as_metadata`, `auth.cimd`: no remote uses OAuth
- n/a `auth.secret_in_url`: no templated URL

### tool hygiene: 100 (weight 30)

- pass `tools.descriptions`: every tool has a description
- pass `tools.description_length`: descriptions are concise
- pass `tools.schemas`: every tool has an object input schema
- pass `tools.annotations`: 26 of 26 tools declare readOnlyHint or destructiveHint
- pass `tools.directory_hints`: every tool declares readOnlyHint, destructiveHint, idempotentHint and openWorldHint
- pass `tools.token_cost`: about 7,367 tokens to load every tool
- pass `tools.api_dump`: tools are not a one-to-one API dump
- pass `tools.hidden_text`: no hidden text in tool names, descriptions, schemas or annotations

### stability: n/a (weight 15)

- n/a `stability.changes`, `stability.rug_pull`, `stability.new_links`: tool history recorded for 1 of the 7 days needed

### dependencies: n/a (weight 15)

- n/a `deps.known_vulns`, `deps.mcp_sdk_version`, `deps.resolvable`: no npm or PyPI package

- tools: 26, about 7,367 tokens to load them all
- tool set hash: 325dbe5892a425f431168ea8083c59c5
- badge: [![protogrid quality](https://protogrid.dev/badge/io.github.yuli3/oiyo-calculations.svg)](https://protogrid.dev/servers/io.github.yuli3/oiyo-calculations)
- Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed.

### Tool changes

_No tool definition changes recorded._

## Remotes

- https://api-oiyo.861106.workers.dev/mcp (streamable-http, auth none, reachable true, uptime30d 0.85714287)
- https://api.oiyo.net/mcp (streamable-http, auth unknown, reachable false, uptime30d 0.8888889)

## Packages

_none_

## Tools (26)

- `calculate_annual_leave`: Calculates statutory annual paid leave days (연차 휴가) and unused leave cash-out allowance by years of service.
- `calculate_cagr`: Calculates Compound Annual Growth Rate (CAGR, 연평균 복합 성장률), total ROI, and Rule of 72 milestone.
- `calculate_capital_gains_tax`: Calculates South Korea Real Estate Capital Gains Tax with 1-home 1.2 billion KRW exemption, high-value house apportionment, and up to 80% special long-term holding deduction.
- `calculate_card_tax_deduction`: Calculates South Korea 2026 year-end card tax deduction, 25% threshold, credit (15%) vs check (30%) rates, and golden ratio strategy.
- `calculate_compound_interest`: Simulates compound interest growth with initial principal, annual yield, recurring monthly contributions, and annual balance trajectory.
- `calculate_gas_bill`: Calculates South Korea residential city gas invoice amount based on cubic meters used and heating/cooking tariff.
- `calculate_health_insurance`: Calculates Korean regional insurance premiums and preliminary income/property flags only. dependentEligibility.isEligible is null: family support, spouse/sibling conditions, housing rental income and statutory exceptions require NHIS review.
- `calculate_inheritance_gift_tax`: Calculates South Korea 2026 statutory inheritance and gift tax, progressive tax brackets (10-50%), relationship deductions, and voluntary filing discount.
- `calculate_kr_acquisition_tax`: South Korea 2026 housing acquisition tax (주택 취득세) with local education tax and rural special tax: 1-3% standard rate (6-900M KRW sliding formula) or 8%/12% multi-home surcharge. Same formulas as tools.oiyo.net. Returns statute basis; does not judge house counts or first-home relief.
- `calculate_kr_freelancer_income_tax`: South Korea freelancer (3.3% withholding, 사업소득) May comprehensive income tax estimate: simple expense rate 940909 (64.1%, 49.7% above 40M KRW) or a given expense ratio, compared with the tax already withheld to show refund or extra payment. Same formulas as tools.oiyo.net. Tax years 2025 and 2026 only; refuses unknown inputs.
- `calculate_kr_property_tax`: South Korea 2026 housing property tax (주택 재산세) from the official price: fair market value ratio (43-45% for one-home households, 60% otherwise), one-home special rate up to 900M KRW, urban area tax and local education tax. Same formulas as tools.oiyo.net. Excludes comprehensive real estate holding tax and the burden cap.
- `calculate_kr_year_end_settlement`: South Korea 2026 귀속 year-end tax settlement (연말정산) for a resident wage earner: income deductions, card deduction, special deductions/credits vs the 130,000 KRW standard credit (picks the lower tax), refund or extra payment when withheld tax is given. Same formulas as tools.oiyo.net. Refuses unknown inputs and tax years other than 2026; returns statute basis and what is not covered. Estimate, not tax advice.
- `calculate_loan_refinance`: Calculates loan refinancing savings, prepayment penalty fees with 3-year sliding taper, and break-even point in months.
- `calculate_military_service`: Calculates South Korea mandatory military service duration, completion rate, remaining days, and rank promotion dates.
- `calculate_net_salary`: Calculates net monthly take-home salary after the 4 major social insurances (2026 statutory rates) and an ESTIMATED income tax (annualized estimate, not the NTS withholding table) in South Korea.
- `calculate_overtime_pay`: Calculates statutory overtime, night, and holiday allowances under Korean Labor Standards Act.
- `calculate_saju_astrology`: Computes traditional Korean Sexagenary Cycle (60 Gapja) Four Pillars and Five Elements (오행) balance from birth datetime and solar/lunar calendar.
- `calculate_severance_pay`: South Korean statutory severance arithmetic. Unknown or mixed four-week hours return null eligibility and amount; all-period self-confirmation is required for an estimate.
- `calculate_unemployment_benefits`: Simulates statutory South Korean unemployment benefits (실업급여) duration, daily benefit rate, and total expected payout.
- `calculate_weekly_allowance`: Calculates statutory South Korean weekly holiday allowance (주휴수당) for part-time and hourly workers.
- `check_kr_business_day`: Determines if a given date is a South Korea working business day or a public holiday/weekend.
- `compare_vat_tax`: Compares South Korea Value-Added Tax (VAT) between General Taxpayer (10% with full deduction/refund) and Simplified Taxpayer (15-40% value-added rate, 48M exemption, no refund).
- `convert_units`: Universal deterministic unit conversion for area (pyeong ↔ m², sqft, ha), length, mass, and temperature.
- `diagnose_hug_guarantee`: Diagnoses HUG Jeonse Deposit Return Guarantee eligibility (126% rule, 60% senior debt limit, 90% debt ratio limit) and calculates statutory guarantee fee.
- `get_kr_holidays`: Get official South Korea public holidays, substitute holidays, and solar terms for a given year.
- `get_kr_minimum_wage`: Verified Korean minimum wage by year, effective dates and 8/209-hour examples. Not a 2027 net-salary calculator; uncollected insurance is unavailable.