Korea Filings

Machine-ready English summaries of Korean corporate disclosures (DART · 전자공시), paid per call in USDC over the x402 protocol on Base. Built for AI agents, quant funds, and research platforms that need programmatic access to Korean market events without reading Korean PDFs.

Live: https://koreafilings.com · API at https://api.koreafilings.com · interactive docs at /swagger-ui.

What it does

Raw DART data is free, but it's in Korean and structured for human filings clerks, not LLMs. Korea Filings turns every disclosure into a structured, cached, English-summarised JSON payload an agent can consume in one call:

{
  "rcptNo": "20260424900874",
  "summaryEn": "Global SM's stock trading was temporarily suspended on April 24, 2026, due to a change in electronic registration related to a stock consolidation or split.",
  "importanceScore": 10,
  "eventType": "SINGLE_STOCK_TRADING_SUSPENSION",
  "sectorTags": ["Capital Goods"],
  "tickerTags": ["095440"],
  "actionableFor": ["traders", "long_term_investors"],
  "generatedAt": "2026-04-24T08:47:51Z"
}

The cache is the moat — the first agent to request a disclosure pays for the LLM run; every subsequent agent for the same rcpt_no hits a near-zero-cost DB lookup and still pays the same fixed fee. Margins compound as adoption grows.

How to use it

Pick whichever surface fits your stack. All three speak the same x402 flow under the hood; the wallet that signs the X-PAYMENT header is the identity. No API keys. No signup.

Python SDK

pip install koreafilings

from koreafilings import Client

with Client(private_key="0x...", network="base-sepolia") as client:
    summary = client.get_summary("20260424900874")

    print(f"[{summary.importance_score}/10] {summary.event_type}")
    print(summary.summary_en)
    print("paid:", client.last_settlement.tx_hash)

MCP server (Claude Desktop, Cursor, Continue, …)

uv tool install koreafilings-mcp

In your MCP client's config:

{
  "mcpServers": {
    "koreafilings": {
      "command": "uv",
      "args": ["tool", "run", "koreafilings-mcp"],
      "env": {
        "KOREAFILINGS_PRIVATE_KEY": "0x...",
        "KOREAFILINGS_NETWORK": "base-sepolia"
      }
    }
  }
}

Two tools become available:

• get_pricing — free; returns the live wallet, network, USDC contract, and per-endpoint price.
• get_disclosure_summary(rcpt_no) — paid; returns the structured summary plus the on-chain settlement transaction hash.

curl / direct HTTP

# 1) Probe the endpoint without payment to discover the requirements.
curl -i https://api.koreafilings.com/v1/disclosures/20260424900874/summary
#   HTTP/2 402
#   payment-required: <base64 PaymentRequired payload>
#   { "x402Version": 2, "accepts": [{ "scheme": "exact", ... }], ... }

# 2) Sign an EIP-3009 TransferWithAuthorization for one of the entries
#    in `accepts`, base64-encode the signed PaymentPayload, and resend
#    with the X-PAYMENT header. See testclient/payer.py for a 90-line
#    reference implementation.
curl -H "X-PAYMENT: $SIGNED" \
     https://api.koreafilings.com/v1/disclosures/20260424900874/summary
#   HTTP/2 200
#   x-payment-response: <base64 SettlementResponse with tx hash>
#   { "rcptNo": "...", "summaryEn": "...", ... }

Pricing

Endpoint	Method	Price (USDC)
/v1/disclosures/{rcptNo}/summary	GET	0.005

The full machine-readable pricing descriptor (current wallet, network, USDC contract, all paid endpoints) lives at /v1/pricing.

Currently on Base Sepolia testnet — testnet USDC is free from the Circle faucet, so anyone can try the service end-to-end without spending real money. The mainnet code path (Coinbase CDP facilitator with Ed25519 JWT auth) is wired and unit tested; the switch is a single environment variable when the first paying customer signals interest.

Architecture

Three logical subsystems share one Spring Boot application:

1. Ingestion — schedules a 30-second poll against the DART Open API, deduplicates by rcpt_no, persists raw metadata to Postgres, enqueues a summarisation job.
2. Summarisation — consumes summarisation jobs, classifies complexity, routes to Gemini 2.5 Flash-Lite (with Resilience4j rate-limiting + circuit-breaking + retries), persists English summary + ticker / sector tags + audit row to llm_audit.
3. Paid API — Spring MVC controller behind an X402PaywallInterceptor. Every request: check X-PAYMENT, verify the signature with the facilitator, check Redis for replay, settle on a 200 response, and attach X-PAYMENT-RESPONSE carrying the on-chain tx hash via a ResponseBodyAdvice. The interceptor short-circuits for handler methods without @X402Paywall, so /v1/pricing, /.well-known/x402, and the OpenAPI document stay unauthenticated.

The 402 challenge follows the x402 v2 transport spec: the PAYMENT-REQUIRED header carries the base64-encoded PaymentRequired payload (with the bazaar extension declaring an input/output schema for AI-agent discoverability), while the body keeps a v1-compatible JSON copy so older clients keep working.

Stack: Java 21, Spring Boot 3.4, PostgreSQL 16, Redis 7, Docker Compose, Cloudflare Tunnel, Cloudflare Workers, Hetzner CAX11. See docs/ARCHITECTURE.md for deeper notes.

Repository layout

.
├── src/                  # Spring Boot application source
├── sdk/python/           # `koreafilings` Python SDK (PyPI)
├── mcp/                  # `koreafilings-mcp` MCP server (PyPI)
├── landing/              # Marketing landing page (Cloudflare Workers)
├── testclient/           # Reference Python x402 client (testnet payer)
├── docs/
│   ├── ARCHITECTURE.md   # System design
│   ├── PRD.md            # Product requirements
│   ├── ROADMAP.md        # Six-week launch plan
│   └── STATUS.md         # Operator handoff notes
├── Dockerfile            # Multi-stage prod build (eclipse-temurin:21)
├── docker-compose.yml    # postgres + redis + app + cloudflared
└── build.gradle.kts      # Gradle (Kotlin DSL)

Local development

git clone https://github.com/OldTemple91/korea-filings-api.git
cd korea-filings-api

cp .env.example .env
# Fill in:
#   POSTGRES_PASSWORD     (any strong password)
#   DART_API_KEY          (free, register at https://opendart.fss.or.kr/)
#   GEMINI_API_KEY        (free tier, https://aistudio.google.com/apikey)
#   X402_RECIPIENT_ADDRESS (your receiving wallet — only the address)

docker compose up -d postgres redis
./gradlew bootRun

To exercise a real x402 payment against a local instance, copy testclient/.env.testclient.example to testclient/.env.testclient, fill in a Base Sepolia wallet's private key (a fresh wallet funded from the Circle faucet is the safe pattern), and run python testclient/payer.py.

Status

Live on Base Sepolia, MVP feature set:

• DART real-time ingestion (30-second poll)
• Gemini 2.5 Flash-Lite summarisation with importance scoring + sector / ticker tagging
• x402 v2 paywall with bazaar extension for agent-discoverable invocation
• Discovery via /.well-known/x402
• OpenAPI 3 spec at /v3/api-docs + interactive Swagger UI
• Python SDK and MCP server published to PyPI
• Indexed by x402scan
• Production deploy on Hetzner via Cloudflare Tunnel

Coming next:

• Base mainnet flip (CDP facilitator code already wired and unit-tested)
• Additional paid endpoints: /disclosures/latest, /by-ticker/{ticker}, POST /filter, SSE /stream, /impact
• TypeScript SDK
• Korean-language landing page

See docs/ROADMAP.md for the full plan.

Contributing

Issues and PRs are welcome — particularly:

• Ports of the Python SDK to other languages (TypeScript, Go, Rust)
• Additional analytics endpoints (price reaction, comparable filings, …)
• Integrations with non-x402 agent frameworks
• Translation of the landing page into other languages

For substantial changes, please open an issue first describing the direction so we can sanity-check fit before you build.

License

MIT.