{ "openapi": "3.1.0", "info": { "title": "Kit Rx Agent Trust: x402 Preflight, Finder & Sanctions API", "version": "1.0.0", "description": "x402 preflight (what a paid endpoint will charge, canonical USDC check, risk flags), an x402 API finder that searches public directories and live-checks results, OFAC SDN sanctions screening for crypto addresses and names, and a decoded receipt of your own x402 payment. Each call is one x402 v2 payment in USDC on Base, Polygon, Arbitrum, Avalanche or Sei; no signup or API key. Requests that fail or match nothing are not charged.", "x-guidance": "GET endpoints under /v1 take query-string parameters and return JSON. Pay per call with x402 v2 (USDC on Base); only 2xx responses are settled. Parameter details and examples: /llms.txt and /catalog.json.", "contact": { "name": "Kit Rx Agent Trust: x402 Preflight, Finder & Sanctions", "url": "https://trust.kit-rx.com" } }, "servers": [ { "url": "https://trust.kit-rx.com" } ], "x-agentcash-guidance": { "llmsTxtUrl": "https://trust.kit-rx.com/llms.txt" }, "x-agentcash-provenance": { "ownershipProofs": [ "0x562a0a65266b78aaf75c13e4f39c45f8c75b29dfbb8154e3c50d56be8d3b53c6404e59525eb61ef4a7146dca7b4be9ccf4d959196f34c9470db96233a8d132781c" ] }, "x-discovery": { "ownershipProofs": [ "0x562a0a65266b78aaf75c13e4f39c45f8c75b29dfbb8154e3c50d56be8d3b53c6404e59525eb61ef4a7146dca7b4be9ccf4d959196f34c9470db96233a8d132781c" ] }, "paths": { "/v1/x402/receipt": { "get": { "operationId": "x402_receipt", "summary": "x402 payment receipt: decode the payment you sent", "description": "Decodes the x402 v2 PAYMENT-SIGNATURE header sent with the request into a readable receipt: x402 version, scheme, CAIP-2 network and chain name, resource URL, the copied payment requirements, payer, recipient, value in atomic units and USD, USDC contract, nonce, validity window in ISO-8601 with seconds to expiry, signature length and prefix, extension keys, and pass/fail diagnostics. Computed locally, no upstream source.", "tags": [ "x402", "payments", "usdc", "testing", "developer" ], "security": [], "parameters": [ { "name": "echo", "in": "query", "required": false, "description": "Optional text up to 200 characters, returned verbatim in the response for request correlation.", "schema": { "type": "string" }, "example": "test-run-001" } ], "x-payment-info": { "price": { "mode": "fixed", "currency": "USD", "amount": "0.002" }, "protocols": [ { "x402": {} } ], "network": "eip155:8453", "asset": "USDC", "payTo": "0xAf8E0A8a8A0A8f65831b2dD0FFe0c1B804698D70" }, "responses": { "200": { "description": "Report (charged)", "content": { "application/json": { "schema": { "type": "object", "properties": { "query": { "type": "object" }, "result": { "type": "object" }, "sources": { "type": "array", "items": { "type": "object" } }, "notes": { "type": "array", "items": { "type": "string" } }, "attribution": { "type": "array", "items": { "type": "string" } }, "generated_at": { "type": "string", "format": "date-time" } }, "required": [ "query", "result", "sources", "generated_at" ] }, "example": { "query": { "echo": "test-run-001" }, "result": { "payment_header_present": true, "header_used": "payment-signature", "header_bytes": 7308, "decoded": true, "encoding": "base64", "error": null, "payment": { "x402_version": 2, "scheme": "exact", "network": "eip155:8453", "network_caip2": "eip155:8453", "network_name": "Base", "resource": { "url": "https://api.kit-rx.com/v1/x402/receipt", "description": "Decodes the x402 v2 PAYMENT-SIGNATURE header sent with the request into a readable receipt: x402 version, scheme, CAIP-2 network and chain name, resource URL, the copied payment requirements, payer, recipient, value in atomic units and USD, USDC contract, nonce, validity window in ISO-8601 with seconds to expiry, signature length and prefix, extension keys, and pass/fail diagnostics. Computed locally, no upstream source.", "mimeType": "application/json" }, "accepted": { "scheme": "exact", "network": "eip155:8453", "amount": "2000", "amount_usd": "0.002", "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913", "payTo": "0xAf8E0A8a8A0A8f65831b2dD0FFe0c1B804698D70", "maxTimeoutSeconds": 300, "extra": { "name": "USD Coin", "version": "2" } }, "transfer_method": "eip3009", "payer": "0x3f1D5e8a1B2c7b0E9F4d6A8c2E5b7D9f1A3c5E7b", "to": "0xAf8E0A8a8A0A8f65831b2dD0FFe0c1B804698D70", "value_atomic": "2000", "value_usd": "0.002", "value_usd_basis": "known Base USDC contract, 6 decimals", "asset": { "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913", "symbol": "USDC", "decimals": 6 }, "nonce": "0x9b7e2c4d61a0f3e85d2b47c91e06fa3b8c5d17e29f40b6a3c8e1d5f7a2b4c6e8", "valid_after": { "field": "authorization.validAfter", "unix": 0, "iso": "1970-01-01T00:00:00.000Z" }, "valid_before": { "field": "authorization.validBefore", "unix": 1794603900, "iso": "2026-11-13T21:05:00.000Z", "seconds_until_expiry": 296, "expired": false }, "signature": { "length_chars": 132, "bytes": 65, "prefix": "0x5c1f3a9e", "kind": "ecdsa_65_bytes" }, "extension_keys": [ "bazaar" ], "top_level_keys": [ "x402Version", "payload", "extensions", "resource", "accepted" ], "payload_keys": [ "authorization", "signature" ] }, "diagnostics": [ { "id": "to_matches_payTo", "check": "authorization.to equals accepted.payTo", "status": "pass", "detail": "Both are 0xAf8E0A8a8A0A8f65831b2dD0FFe0c1B804698D70." }, { "id": "value_matches_amount", "check": "Signed value equals accepted.amount", "status": "pass", "detail": "Both are 2000 atomic units." }, { "id": "valid_before_future", "check": "validBefore is in the future", "status": "pass", "detail": "Expires in 296 s." }, { "id": "valid_after_reached", "check": "validAfter is not in the future", "status": "pass", "detail": "The authorization window has opened." }, { "id": "network_recognized", "check": "Network is a recognized x402 USDC network", "status": "pass", "detail": "eip155:8453 is Base." } ], "diagnostics_summary": { "pass": 5, "fail": 0, "skipped": 0 }, "server_time": "2026-11-13T21:00:04.512Z", "echo": "test-run-001", "settlement_note": "On-chain settlement happens after this body is produced: the facilitator submits the signed transfer once the handler returns 200. The transaction hash arrives in this same response's PAYMENT-RESPONSE header (base64 JSON with success, transaction, network and payer)." }, "sources": [], "attribution": [ "No third-party data: computed from this request's own payment header. Network names and USDC contract addresses follow the default asset table of the x402 reference implementation (@x402/evm, Apache-2.0)." ], "generated_at": "2026-11-13T21:00:04.513Z" } } } }, "400": { "description": "Invalid input (not charged)" }, "402": { "description": "Payment required: x402 challenge in the PAYMENT-REQUIRED header" }, "404": { "description": "No match (not charged)" }, "502": { "description": "Upstream source unavailable (not charged)" } } } }, "/v1/x402/preflight": { "get": { "operationId": "x402_preflight", "summary": "x402 preflight: inspect a paid endpoint before paying", "description": "Sends an unpaid GET to an x402 endpoint and reports what it would charge before paying: HTTP status, redirects (max 3, re-validated), v2 PAYMENT-REQUIRED header or v1 body challenge and its validity, each accepts entry (scheme, CAIP-2 network/name, atomic amount, USD for canonical USDC, asset check, payTo, timeout, EIP-712 name/version), OFAC SDN payTo screen, resource, Bazaar extension, risk flags, host context from registry RDAP (registrar, domain age) and Cloudflare DoH.", "tags": [ "x402", "payments", "usdc", "security", "developer" ], "security": [], "parameters": [ { "name": "url", "in": "query", "required": true, "description": "https:// URL of the x402 endpoint, including any query string, up to 2048 characters. Default port only; no embedded credentials, IP-address hosts, localhost or private names.", "schema": { "type": "string" }, "example": "https://api.kit-rx.com/v1/x402/receipt" } ], "x-payment-info": { "price": { "mode": "fixed", "currency": "USD", "amount": "0.005" }, "protocols": [ { "x402": {} } ], "network": "eip155:8453", "asset": "USDC", "payTo": "0xAf8E0A8a8A0A8f65831b2dD0FFe0c1B804698D70" }, "responses": { "200": { "description": "Report (charged)", "content": { "application/json": { "schema": { "type": "object", "properties": { "query": { "type": "object" }, "result": { "type": "object" }, "sources": { "type": "array", "items": { "type": "object" } }, "notes": { "type": "array", "items": { "type": "string" } }, "attribution": { "type": "array", "items": { "type": "string" } }, "generated_at": { "type": "string", "format": "date-time" } }, "required": [ "query", "result", "sources", "generated_at" ] }, "example": { "query": { "url": "https://api.kit-rx.com/v1/x402/receipt" }, "result": { "requested_url": "https://api.kit-rx.com/v1/x402/receipt", "final_url": "https://api.kit-rx.com/v1/x402/receipt", "http": { "status": 402, "content_type": "application/json", "latency_ms": 329, "redirects": [], "redirect_stopped": null }, "is_x402": true, "x402_version": 2, "challenge_source": "payment-required header", "challenge_valid": true, "challenge_problems": [], "server_error": "Payment required", "resource": { "url": "https://api.kit-rx.com/v1/x402/receipt", "description": "Decodes the x402 v2 PAYMENT-SIGNATURE header sent with the request into a readable receipt: …", "mimeType": "application/json" }, "accepts_count": 5, "accepts": [ { "index": 0, "scheme": "exact", "network": "eip155:8453", "network_caip2": "eip155:8453", "network_name": "Base", "testnet": false, "amount_atomic": "2000", "amount_usd": "0.002", "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913", "asset_is_canonical_usdc": true, "asset_note": null, "pay_to": "0xAf8E0A8a8A0A8f65831b2dD0FFe0c1B804698D70", "max_timeout_seconds": 300, "transfer_method": "eip3009", "eip712": { "name": "USD Coin", "version": "2", "present": true, "matches_usdc_contract": true }, "extra_keys": [ "name", "version" ], "problems": [] }, { "index": 1, "scheme": "exact", "network": "eip155:137", "network_caip2": "eip155:137", "network_name": "Polygon", "testnet": false, "amount_atomic": "2000", "amount_usd": "0.002", "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359", "asset_is_canonical_usdc": true, "asset_note": null, "pay_to": "0xAf8E0A8a8A0A8f65831b2dD0FFe0c1B804698D70", "max_timeout_seconds": 300, "transfer_method": "eip3009", "eip712": { "name": "USD Coin", "version": "2", "present": true, "matches_usdc_contract": true }, "extra_keys": [ "name", "version" ], "problems": [] } ], "price_usd": { "min": "0.002", "max": "0.002" }, "bazaar": { "present": true, "info_present": true, "schema_present": true, "input_type": "http", "method": "GET", "query_params": [ "echo" ], "output_example_present": true }, "extension_keys": [ "bazaar" ], "risk_flags": [], "risk_summary": { "high": 0, "medium": 0, "low": 0 }, "ofac": { "source": "U.S. Treasury OFAC SDN List", "list_date": "2026-11-13", "checked": [ "0xAf8E0A8a8A0A8f65831b2dD0FFe0c1B804698D70" ], "match": false, "matches": [] }, "host": { "host": "api.kit-rx.com", "registrable_domain": "kit-rx.com", "platform": null, "dns": { "a": [ "104.21.58.22", "172.67.198.112" ], "aaaa": [ "2606:4700:3035::6815:3a16", "2606:4700:3033::ac43:c670" ], "all_public": true }, "registration": { "rdap": "found", "registrar": "Squarespace Domains II LLC", "registrar_iana_id": "895", "created": "2025-12-04T00:21:00.000Z", "age_days": 346 } } }, "sources": [ { "name": "Unpaid GET of the endpoint (no payment header)", "url": "https://api.kit-rx.com/v1/x402/receipt" }, { "name": "Cloudflare DNS over HTTPS (JSON API)", "url": "https://cloudflare-dns.com/dns-query" }, { "name": "IANA RDAP bootstrap", "url": "https://data.iana.org/rdap/dns.json" }, { "name": "Registry RDAP (rdap.verisign.com)", "url": "https://rdap.verisign.com/com/v1/domain/kit-rx.com" } ], "attribution": [ "DNS resolved via Cloudflare 1.1.1.1 DNS-over-HTTPS.", "Registration data from the domain's registry via RDAP, subject to that registry's terms; provided for per-domain due diligence only, not for bulk collection or marketing." ], "generated_at": "2026-11-15T01:05:48.404Z" } } } }, "400": { "description": "Invalid input (not charged)" }, "402": { "description": "Payment required: x402 challenge in the PAYMENT-REQUIRED header" }, "404": { "description": "No match (not charged)" }, "502": { "description": "Upstream source unavailable (not charged)" } } } }, "/v1/x402/find": { "get": { "operationId": "x402_find", "summary": "x402 finder: search paid APIs, ranked and live-checked", "description": "Search and discovery of paid x402 API endpoints for a plain-language need, across Ultravioleta DAO x402 Bazaar and 402 Index directories. Dedupes by resource URL; ranks by relevance, verification, uptime, price and recency. Each result: resource URL, short description, USDC price, CAIP-2 networks, sources, verification. The top 3 GET endpoints get a live unpaid check: valid x402 402, live price, networks, canonical USDC, risk flags, OFAC SDN payTo screen, RDAP domain age.", "tags": [ "x402", "discovery", "search", "trust", "payments" ], "security": [], "parameters": [ { "name": "q", "in": "query", "required": true, "description": "What the agent needs, in plain words, 2-120 characters (e.g. weather forecast for a US city, token price, web page to markdown).", "schema": { "type": "string" }, "example": "weather forecast" }, { "name": "max_price", "in": "query", "required": false, "description": "Highest acceptable price per call in USD as a decimal, e.g. 0.01. Listings without a USDC price are left out when set.", "schema": { "type": "string" }, "example": "0.01" }, { "name": "network", "in": "query", "required": false, "description": "Only endpoints that accept canonical USDC on this network.", "schema": { "type": "string", "enum": [ "base", "polygon", "arbitrum", "avalanche", "sei", "solana" ] } }, { "name": "limit", "in": "query", "required": false, "description": "Number of results, 1-10 (default 5).", "schema": { "type": "integer" }, "example": "3" } ], "x-payment-info": { "price": { "mode": "fixed", "currency": "USD", "amount": "0.01" }, "protocols": [ { "x402": {} } ], "network": "eip155:8453", "asset": "USDC", "payTo": "0xAf8E0A8a8A0A8f65831b2dD0FFe0c1B804698D70" }, "responses": { "200": { "description": "Report (charged)", "content": { "application/json": { "schema": { "type": "object", "properties": { "query": { "type": "object" }, "result": { "type": "object" }, "sources": { "type": "array", "items": { "type": "object" } }, "notes": { "type": "array", "items": { "type": "string" } }, "attribution": { "type": "array", "items": { "type": "string" } }, "generated_at": { "type": "string", "format": "date-time" } }, "required": [ "query", "result", "sources", "generated_at" ] }, "example": { "query": { "q": "weather forecast", "max_price": "0.01", "limit": 3 }, "result": { "results": [ { "rank": 1, "resource": "https://verify-oracle.run402.com/api/weather", "title": "VerifyOracle", "provider": null, "description": "Live weather forecast and current temperature in Fahrenheit and Celsius with precipitation and wind from Open-Meteo and NWS (default New York).", "method": "GET", "price_usd": "0.001", "networks": [ "eip155:8453" ], "sources": [ "ultravioleta" ], "verification": { "status": "verified", "ultravioleta": { "health": "alive", "verified_by": "x402_challenge", "verified_at": "2026-11-13T00:36:14.000Z", "uptime_pct": 100, "tier": "verified", "calls_30d": 0, "unique_payers_30d": 0 } }, "score": 0.964, "live_check": { "checked": true, "verdict": "pass", "http_status": 402, "latency_ms": 221, "is_x402": true, "x402_version": 2, "challenge_valid": true, "price_usd": { "min": "0.001", "max": "0.001" }, "networks": [ "eip155:8453" ], "canonical_usdc": true, "ofac_sdn_match": false, "risk_flags": [], "problems": [], "domain": { "registrable": "run402.com", "platform": null, "age_days": 261, "rdap": "found" } } }, { "rank": 2, "resource": "https://quantagentshop.com/v1/weather", "title": "Quant Agent Shop", "provider": null, "description": "Weather forecast for coordinates or a city name: current temperature, humidity, wind …", "method": "POST", "price_usd": "0.0013", "networks": [ "eip155:8453" ], "sources": [ "ultravioleta" ], "verification": { "status": "verified" }, "score": 0.941, "live_check": { "checked": false, "verdict": null, "reason": "Not checked: the listing declares POST; the live check sends an unpaid GET only." } } ], "counts": { "ultravioleta": { "status": "ok", "returned": 14, "matched": 10 }, "402index": { "status": "ok", "returned": 20, "matched": 19 }, "merged": 34, "dropped": { "below_relevance": 4, "over_max_price": 0, "network_mismatch": 0, "reported_down": 1 }, "after_filters": 29, "returned": 3, "live_checked": 2 } }, "sources": [ { "name": "Ultravioleta DAO x402 Bazaar (discovery API)", "url": "https://facilitator.ultravioletadao.xyz/discovery/resources" }, { "name": "402 Index public API (402index.io)", "url": "https://402index.io/api/v1/services" } ], "generated_at": "2026-11-15T00:39:59.536Z" } } } }, "400": { "description": "Invalid input (not charged)" }, "402": { "description": "Payment required: x402 challenge in the PAYMENT-REQUIRED header" }, "404": { "description": "No match (not charged)" }, "502": { "description": "Upstream source unavailable (not charged)" } } } }, "/v1/compliance/sanctions": { "get": { "operationId": "compliance_sanctions", "summary": "OFAC sanctions screening: crypto wallet or name", "description": "OFAC sanctions (AML/KYC) screening of a crypto wallet or a person, company, vessel or aircraft name against a dated snapshot of the U.S. Treasury SDN and non-SDN Consolidated lists. Address mode: exact match on OFAC-listed digital currency addresses (BTC, ETH/EVM, USDT, TRX, XMR, LTC, more). Name mode: fuzzy match on names and strong aliases ignoring case, accents, punctuation and word order, scored 0-100. Returns match flag, OFAC uid, type, programs, country, list date.", "tags": [ "sanctions", "ofac", "compliance", "aml", "crypto" ], "security": [], "parameters": [ { "name": "address", "in": "query", "required": false, "description": "Crypto wallet address (20 to 120 characters) checked for an exact match against OFAC-listed digital currency addresses; EVM 0x, bech32 and CashAddr addresses match case-insensitively (bitcoincash: prefix optional). Mutually exclusive with name.", "schema": { "type": "string" }, "example": "0x098B716B8Aaf21512996dC57EB0615e2383E2f96" }, { "name": "name", "in": "query", "required": false, "description": "Person, company, vessel or aircraft name, 2 to 120 characters, in Latin script; case, accents, punctuation and word order are ignored. Mutually exclusive with address.", "schema": { "type": "string" }, "example": "Vladimir Putin" }, { "name": "threshold", "in": "query", "required": false, "description": "Minimum name match score from 70 to 100 (default 85); the score mainly reflects how closely every query word matches a word of the listed name. Name mode only.", "schema": { "type": "integer" }, "example": "85" } ], "x-payment-info": { "price": { "mode": "fixed", "currency": "USD", "amount": "0.01" }, "protocols": [ { "x402": {} } ], "network": "eip155:8453", "asset": "USDC", "payTo": "0xAf8E0A8a8A0A8f65831b2dD0FFe0c1B804698D70" }, "responses": { "200": { "description": "Report (charged)", "content": { "application/json": { "schema": { "type": "object", "properties": { "query": { "type": "object" }, "result": { "type": "object" }, "sources": { "type": "array", "items": { "type": "object" } }, "notes": { "type": "array", "items": { "type": "string" } }, "attribution": { "type": "array", "items": { "type": "string" } }, "generated_at": { "type": "string", "format": "date-time" } }, "required": [ "query", "result", "sources", "generated_at" ] }, "example": { "query": { "address": "0x098B716B8Aaf21512996dC57EB0615e2383E2f96" }, "result": { "mode": "address", "list_date": "2026-11-13", "list_age_days": 2, "lists": [ { "list": "SDN", "publish_date": "2026-11-13", "records": 19565 }, { "list": "Non-SDN Consolidated", "publish_date": "2026-11-04", "records": 486 } ], "match": true, "match_count": 1, "matches": [ { "uid": 27307, "name": "LAZARUS GROUP", "matched_alias": null, "type": "entity", "lists": [ "SDN" ], "programs": [ "DPRK3" ], "country": "Korea, North", "score": 100, "matched_address": "0x098B716B8Aaf21512996dC57EB0615e2383E2f96", "currencies": [ "ETH" ] } ], "source": "U.S. Treasury OFAC SDN List", "disclaimer": "Screening aid only, not a legal determination. Matches come from a bundled OFAC list snapshot (see list_date) and can miss designations or removals made after it. …" }, "sources": [ { "name": "OFAC Sanctions List Service: SDN List (bundled snapshot)", "url": "https://sanctionslistservice.ofac.treas.gov/api/PublicationPreview/exports/SDN.XML" }, { "name": "OFAC Sanctions List Service: Consolidated (non-SDN) List (bundled snapshot)", "url": "https://sanctionslistservice.ofac.treas.gov/api/PublicationPreview/exports/CONSOLIDATED.XML" } ], "notes": [ "EVM addresses are compared case-insensitively; a listed EVM address is flagged whatever chain or token OFAC recorded it under." ], "attribution": [ "Sanctions data from the U.S. Department of the Treasury, Office of Foreign Assets Control (OFAC) Sanctions List Service; U.S. government work, not subject to copyright (17 U.S.C. 105). Kit Rx is not affiliated with or endorsed by OFAC or Treasury. Bundled snapshot: see list_date." ], "generated_at": "2026-11-15T00:37:12.574Z" } } } }, "400": { "description": "Invalid input (not charged)" }, "402": { "description": "Payment required: x402 challenge in the PAYMENT-REQUIRED header" }, "404": { "description": "No match (not charged)" }, "502": { "description": "Upstream source unavailable (not charged)" } } } } } }