What is a KYB (Know-Your-Business) check API?

A KYB check verifies a business counterparty before you onboard or transact with it — who they legally are, whether they're sanctioned, and (for crypto-native or online counterparties) their domain and wallet posture. This API merges five checks into one call: company identity (SEC EDGAR + GLEIF LEI), OFAC sanctions screening (name + wallet), domain RDAP/DNS posture, Base wallet activity/risk, and email deliverability.

Is there a free company due diligence API?

Yes. This page's free preview calls POST /free/v1/kyb_pack directly (no account, no key, rate-limited, reduced fields) and the paid POST /v1/kyb_pack (full per-section detail, sources, and caveats, USDC on Base via x402) uses the identical live builder and internal handlers.

Does this call five separate APIs and charge five times?

No — one call, one price. The paid route is a flat $0.05 regardless of how many of the five sections your input triggers (up to $0.064 if you called company_lookup, sanctions_screen, domain_intel, wallet_profile, and email_validate separately). Sections run in parallel, each under its own timeout; a failing section comes back status "unavailable" instead of failing the whole call, and you're only ever charged when the response is actually useful.

Guide + free preview · KYB / company due diligence

KYB Check API — Company Due Diligence in One Call

By draconic21 · Published 2026-09-30 · Sources: SEC EDGAR, GLEIF, OFAC SDN, RDAP registries, live DNS, Base public chain data

Onboarding a new counterparty, vendor, or agent usually means several separate lookups — who they legally are, whether they're sanctioned, and (for online or crypto-native counterparties) their domain and wallet posture. This route merges all of that into one call. Here's a free live preview, then the paid API behind it.

Try it free — merged company due-diligence preview

Live, no signup. Fill in any combination — company name/ticker/LEI/CIK, domain, wallet, email — only the matching sections run.

Company name

Domain (optional)

Wallet address (optional)

Email (optional)

What this is — and isn't

Each section calls this catalog's own existing, independently-priced routes directly (no extra HTTP hop): company_lookup (SEC EDGAR public-domain data + GLEIF's CC0 LEI reference API), sanctions_screen (the U.S. Treasury's own published OFAC SDN list — names, aliases, and published digital-currency addresses), domain_intel (RDAP registry data + live DNS/SPF/DMARC), wallet_profile (Base's public RPC + Blockscout explorer), and email_validate (RFC syntax + live MX/DNS, no third-party vendor). Sections run in parallel, each under its own timeout guard — a flaky upstream on one section never costs you the sections that worked, and it shows up as status: "unavailable" with a reason instead of failing the whole call.

It is not a certified compliance program, a KYC verification, or an AML program's sign-off. A flag in the summary.flags list means "review this," not a confirmed finding — a human compliance reviewer should confirm anything flagged before you act on it. Read each section's own caveats in the full response.

Need full per-section detail, sources, and caveats, or agent/API access?

Same merged report, no cap

This free page calls the identical live builder used by the paid API — full per-section fields, sources, and caveats, one flat price no matter how many sections your input triggers.

KYB Due-Diligence Pack, full detail — $0.05/call, USDC on Base, no account → Prefer card billing? Subscribe on the RapidAPI Web Intelligence API → MCP tools — call kyb_pack from any MCP-enabled agent →

Example (x402 pay-per-call)

curl -X POST https://draconic21-x402-api.onrender.com/v1/kyb_pack \
  -H "content-type: application/json" \
  -d '{"name":"Apple Inc.","domain":"apple.com"}'
# unpaid: HTTP 402 + PAYMENT-REQUIRED header (sign with a Base USDC wallet, retry)

Agent / funded runtime? After you verify this feed, the cold-start buy on this origin is POST /v1/signal_latest — $0.03 USDC (Daily Agent Signal). Free wake: GET /health. Skill card: /skill.md · buyer loop: /agent-buy.md.

Independent public-data helper. This page and its linked API read public SEC EDGAR, GLEIF, OFAC, RDAP/DNS, and Base-chain infrastructure — it is not affiliated with, endorsed by, or an official product of the SEC, GLEIF, the U.S. Treasury, any domain registry, or Base/Coinbase. Not a compliance certification, KYC verification, AML program output, financial, or legal advice.