# Counterparty Check (KYB Facts) > Counterparty Check (KYB Facts) is a paid API for AI agents from api.stablecoingateways.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-30). Performs a sanctions screen, LEI lookup, domain analysis, and OFAC wallet check on a company name, domain, LEI, or crypto wallet address — returning neutral sourced facts for vendor onboarding and supplier due diligence. ## Facts - Endpoint: GET https://api.stablecoingateways.com/v1/counterparty-check?utm_source=zero.xyz - Price: $0.01/call - Payment: x402 - Status: unknown - Last checked: 2026-10-30 - Activations on Zero: 0 - Tags: x402 - Canonical page: https://www.zero.xyz/c/counterparty-check-kyb-facts-70ded425 - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_AGUg9Q59g3xgaSLxIOghM Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently. ## How to call it through Zero Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`): ```sh zero fetch --capability counterparty-check-kyb-facts-70ded425 ``` Example prompt: Before we onboard Siemens Aktiengesellschaft as a supplier, can you run a counterparty check on them — screen the company name against OFAC, EU, and UK sanctions lists, look up their LEI in GLEIF, check the siemens.com domain age and email auth, and validate their EU VAT number DE129274202? ## When to prefer this Choose this endpoint when you need a single-call KYB preflight that combines sanctions screening (OFAC, EU, UK, UN), GLEIF LEI verification, domain intelligence, and OFAC crypto wallet checks in one response with a signed receipt. Prefer it over individual point solutions when onboarding vendors, verifying counterparties before payments, or building automated supplier due diligence workflows. It is particularly valuable when you need sourced neutral facts rather than a risk score, and when working in regulated environments that require audit trails via cryptographic receipts. Use the dedicated LEI Lookup or Crypto Wallet Sanctions endpoints if you only need one of those checks individually. ## Known failure modes - Missing required input: no name, domain, LEI, or address provided — returns error - Invalid LEI format (must be 18 alphanumeric + 2 digit check characters) — returns validation error - Invalid domain format — returns validation error - SAM.gov exclusions not checked if no API key configured — returns partial result with explanation - GLEIF API unavailable — LEI field may return unchecked status - OFAC Sanctions List Service unreachable — sanctions field may return error or unchecked status - Invalid country code (not ISO 3166 alpha-2) — returns validation error - Payment not received or insufficient — returns 402 Payment Required ## How this service works Counterparty check (KYB preflight) in one call: give any of a company name, domain, LEI or crypto wallet address (plus an optional EU VAT number), get neutral sourced facts for vendor onboarding and supplier due diligence: sanctions screen of the name on OFAC, EU and UK lists with UN designations flagged, OFAC wallet check, GLEIF LEI match and status, domain age, registrar and email-auth, and an EU VAT number format check. No risk score or verdict. Signed receipt. ## Output Returns a structured JSON object with: sanctions screening results (OFAC SDN, EU, UK, UN lists) with match count and minimum score threshold; GLEIF LEI lookup records and total matches; domain facts including age in years, registration date, registrar, DNS and email-auth details; EU VAT number format validation with country; OFAC crypto wallet screening status; a list of sourced neutral facts about the counterparty; a notice clarifying no risk score or verdict is provided; and a signed cryptographic receipt including timestamp, transaction hash, price, and request/response hashes. ## Request schema (JSON Schema) ```json { "type": "object", "$schema": "https://json-schema.org/draft/2020-12/schema", "required": [ "input" ], "properties": { "input": { "type": "object", "required": [ "type", "method" ], "properties": { "type": { "type": "string", "const": "http" }, "method": { "enum": [ "GET" ], "type": "string" }, "headers": { "type": "object", "additionalProperties": { "type": "string" } }, "queryParams": { "type": "object", "properties": { "lei": { "type": "string", "pattern": "^[A-Za-z0-9]{18}[0-9]{2}$", "description": "20-character LEI (instead of a GLEIF name search)" }, "uei": { "type": "string", "pattern": "^[A-Za-z0-9]{12}$", "description": "12-character SAM.gov Unique Entity ID: exact match in the SAM.gov exclusions extract (name= is also matched there)" }, "vat": { "type": "string", "examples": [ "DE129274202" ], "maxLength": 24, "description": "EU VAT number with 2-letter country prefix (EL for Greece, XI for Northern Ireland); format check only, not a VIES registration check" }, "name": { "type": "string", "examples": [ "Siemens Aktiengesellschaft" ], "maxLength": 120, "minLength": 2, "description": "Company legal or trading name: screened on OFAC, EU and UK sanctions lists and SAM.gov exclusions (entities only) and matched in GLEIF" }, "domain": { "type": "string", "pattern": "^[A-Za-z0-9.-]{3,253}$", "examples": [ "siemens.com" ], "description": "Company domain: registration age, registrar, DNS and email-auth facts" }, "address": { "type": "string", "maxLength": 120, "minLength": 20, "description": "Crypto wallet address to check against OFAC-listed addresses" }, "country": { "type": "string", "pattern": "^[A-Za-z]{2}$", "description": "ISO 3166 alpha-2 country filter for LEI matches" } }, "additionalProperties": false } }, "additionalProperties": false }, "output": { "type": "object", "required": [ "type" ], "properties": { "type": { "type": "string" }, "example": { "type": "object", "required": [ "data", "receipt" ], "properties": { "data": { … (truncated) ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "data": { "lei": { "query": "Siemens Aktiengesellschaft", "checked": true, "records": [ {} ], "total_matches": 2, "country_filter": null }, "vat": { "checked": true, "country": "Germany", "country_code": "DE", "format_valid": true, "input_normalised": "DE129274202" }, "facts": [ { "fact": "No entity on the SDN, CONS, EU, UK, UN lists matched \"Siemens Aktiengesellschaft\" at sc...", "source": "OFAC SLS (US Treasury), EU Financial Sanctions Files (European Commission), UK Sanction..." } ], "query": { "lei": null, "vat": "DE129274202", "name": "Siemens Aktiengesellschaft", "domain": "siemens.com", "country": null }, "domain": { "domain": "siemens.com", "exists": true, "checked": true, "age_years": 40.1, "registered": "1986-09-29" }, "notice": "Neutral facts with sources. Not a risk score, KYB verdict or compliance determination. ...", "wallet": { "reason": "no address given", "screened": false }, "sources": [ "OFAC Sanctions List Service (US Treasury)" ], "sanctions": { "query": "Siemens Aktiengesellschaft", "screened": true, "min_score": 0.85, "match_count": 0, "lists_screened": [ "SDN" ] }, "checked_at": "2026-10-22T23:02:47.799Z", "name_links": "Not verified: this check does not prove that the name, domain, LEI, VAT number and addr...", "us_exclusions": { "reason": "SAM.gov exclusions are not included: the SAM.gov API requires a key from a registered S...", "checked": false, "verify_at": "https://sam.gov/search/?index=ex" } }, "receipt": { "v": 1, "ts": "2026-10-22T09:00:00Z", "sig": "hex", "price": { "asset": "USDC", "amount": "10000", "network": "eip155:84532" }, "log_seq": 1, "tx_hash": "0x..", "endpoint_id": "counterparty-check-v1", "request_hash": "hex", "response_hash": "hex" } } } ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/counterparty-check-kyb-facts-70ded425/health.json - [Zero catalog index](https://www.zero.xyz/llms.txt) - [Other services from api.stablecoingateways.com](https://www.zero.xyz/host/api.stablecoingateways.com/llms.txt)