Korea Business Verify (KBV) — MCP Server

KBV is a hosted MCP server that verifies Korean businesses in real time — free during its pilot phase. Give it a 10-digit Korean business registration number (사업자등록번호) and it returns the registration status (active / suspended / closed), tax type, and — optionally — whether the number matches a representative name and opening date. Data comes live from the Korea National Tax Service (NTS) and is returned as clean, English-normalized JSON.

No account, no API key, no installation — connect any MCP-capable agent to one URL:

https://kbv-server-f7vfitmlkq-du.a.run.app/mcp

Built for AI agents and developers doing KYB / due-diligence on Korean companies: procurement, contracting, payments, marketplace onboarding.

Quick facts

MCP endpoint	https://kbv-server-f7vfitmlkq-du.a.run.app/mcp
Transport	MCP Streamable HTTP (POST)
Health check	GET https://kbv-server-f7vfitmlkq-du.a.run.app/health → {"ok":true}
Authentication	None required
Price	Free (pilot) — pay-per-call planned, see Pricing
Tools	check_korean_business_status, verify_korean_business
Data source	Korea National Tax Service (국세청), official open-data API — queried live per request
Data license	Korean government open data, no usage restrictions (이용허락범위 제한 없음)
Privacy	Query contents are never logged — see Privacy
Region	Google Cloud Run, Seoul (asia-northeast3)

Connect your agent

Claude (claude.ai)

1. Settings → Connectors → Add custom connector
2. URL: https://kbv-server-f7vfitmlkq-du.a.run.app/mcp
3. Enable the connector in a chat and ask: "Check the status of Korean business 124-81-00998."

Claude Code (CLI)

claude mcp add --transport http kbv https://kbv-server-f7vfitmlkq-du.a.run.app/mcp

ChatGPT

1. Settings → Connectors (requires a plan with connector / developer-mode support)
2. Add a custom MCP connector with URL https://kbv-server-f7vfitmlkq-du.a.run.app/mcp
3. Enable it in a conversation and ask about a Korean business number.

Cursor

Add to .cursor/mcp.json (project) or ~/.cursor/mcp.json (global):

{
  "mcpServers": {
    "korea-business-verify": {
      "url": "https://kbv-server-f7vfitmlkq-du.a.run.app/mcp"
    }
  }
}

Any other MCP client

Use transport Streamable HTTP with the endpoint above. Clients must send Accept: application/json, text/event-stream (standard MCP clients do this automatically). Opening /mcp in a browser returns Method not allowed by design — browsers send GET, MCP uses POST. Use /health for a visual liveness check.

Tools

check_korean_business_status

Check the registration status of a Korean business by its 10-digit business registration number.

Input — hyphens/spaces allowed; normalized internally:

{ "business_number": "124-81-00998" }

Output (real example — Samsung Electronics):

{
  "business_number": "1248100998",
  "status": "active",
  "status_code_raw": "01",
  "tax_type": "general",
  "closed_date": null,
  "checked_at": "2026-08-24T10:08:20.082Z",
  "source": "Korea National Tax Service (NTS)",
  "cache": false
}

Field reference:

• status: active | suspended | closed | not_registered
• tax_type: general | simplified | exempt | non_profit | unknown
• closed_date: ISO date ("2023-01-31"), only for closed businesses, otherwise null
• checked_at: ISO 8601 UTC timestamp of the NTS query
• cache: true only when the NTS API was temporarily unavailable and a cached result (max 24 h old) was served; checked_at then reflects the original fetch time

A number that is well-formed but not registered with the NTS returns "status": "not_registered" (not an error).

verify_korean_business

Verify that a business registration number matches the provided representative name and opening date (KYB identity check), and get the current status in the same call.

Input:

{
  "business_number": "124-81-00998",
  "representative_name": "홍길동",
  "opening_date": "1969-01-13",
  "address": "경기도 수원시"
}

• representative_name and opening_date (YYYY-MM-DD) are required.
• address is optional and improves match precision.
• Names and addresses should be given as registered with the NTS (Korean script).

Output — same schema as above plus identity_match:

{
  "business_number": "1248100998",
  "status": "active",
  "status_code_raw": "01",
  "tax_type": "general",
  "closed_date": null,
  "checked_at": "2026-08-24T10:08:23.483Z",
  "source": "Korea National Tax Service (NTS)",
  "cache": false,
  "identity_match": false
}

identity_match is true only when the NTS confirms that the number, representative name, and opening date all match its records.

Errors

Errors are returned as MCP tool errors with a machine-readable JSON body:

error	Meaning
invalid_business_number	Input is not a 10-digit number, or the date is not YYYY-MM-DD. Nothing was queried.
upstream_unavailable	The NTS API is down or over quota and no cached result exists. Retry later.

Data source and license

• All data comes from the Korea National Tax Service (국세청) via the official Korean government open-data API (data.go.kr: 사업자등록정보 진위확인 및 상태조회 서비스), queried live on every request — KBV stores no business database.
• The underlying dataset is published under the Korean government open-data policy with no usage restrictions (이용허락범위: 제한 없음), so responses may be used commercially and cited freely.
• KBV normalizes the Korean-language, code-based NTS responses into the stable English JSON schema documented above; raw NTS payloads are never passed through.
• Freshness: queries hit the NTS registry directly. Newly registered businesses may take 1–2 business days to appear in the NTS system itself.

Privacy

• Query contents are never logged. Business numbers, representative names, and addresses appear in no server logs and are sent nowhere except the official NTS API that answers the query.
• Server logs contain only request counts, outcomes, and latency metrics.
• A short-lived in-memory cache (24 h max, hashed keys) exists solely so the service can answer during NTS outages; it is never shared or exported.

Pricing

• Currently free while KBV is in its pilot phase. No account or key is needed.
• Pay-per-call pricing (in the ~$0.02–$0.05 per call range, agent-payable via x402) is planned for a later phase; the free tier for light usage is expected to remain.
• Fair use: the upstream NTS quota is shared. Heavy automated traffic may be rate-limited before paid tiers launch.

FAQ

What is a Korean business registration number? A 10-digit identifier (사업자등록번호, often written 123-45-67890) issued by the Korea National Tax Service to every registered business in South Korea.

Can I check whether a Korean company is still operating? Yes — call check_korean_business_status; "status": "active" means the business is currently registered and operating, "closed" includes the closure date.

Can I verify a Korean company's identity before a transaction (KYB)? Yes — call verify_korean_business with the number, representative name, and opening date; identity_match: true means the NTS confirms all three match.

Do I need an API key? No. Connect to the MCP URL and call the tools.

Self-hosting / development

The server is open for local development (Node.js ≥ 22, TypeScript, Express + official MCP SDK):

cp .env.example .env       # put your own data.go.kr DECODING key in NTS_SERVICE_KEY
npm install
npm run dev                # → http://localhost:8080  (MCP at /mcp)
npm test                   # vitest, upstream fully mocked — no network

Deployment guide (Google Cloud Run): see DEPLOY.md. Architecture and design spec: DESIGN.md.