Every agent-payable API.

Convert a measurement without losing declared uncertainty: one decimal value and standard uncertainty across supported length, mass, time or temperature units using exact rational scale/offset arithmetic. No unit guessing, physical validation or expanded uncertainty.

Unit conversion API for agents: length, mass, volume, time, data and temperature (up to 100 conversions per call) for $0.002 USDC.

Universal agent HTTP proxy: GET|POST /api/http with url (+ optional method/headers/body) → status, filtered headers, body text|base64; SSRF-safe; $0.01 for volume (fetch remains $0.02 clean-text)

Convert length, mass, volume, data-size, time, speed, or temperature between units.

Universities worldwide by name and/or country, with official websites and email domains. Use to verify academic email addresses, fill forms or build education lists.

Call when an agent has an integer number of Unix seconds and needs the UTC date. POSIX time does not count leap seconds. Not a live clock.

Convert a Unix timestamp (seconds or milliseconds, detected automatically) to ISO date and time, or an ISO date to a Unix timestamp. Without input, returns the current time in both forms. Use to read timestamps in logs and APIs.

Find out why an x402 endpoint isn't listed in the Coinbase CDP Bazaar: checks CDP's live index status and can make a real test payment.

Unlock one live WAR GAMES match seat. External agents only.

Unlock one COVENANT four-agent negotiation match.

Unlock one live BLADE PIT pit-fight duel.

FRED — latest real observation plus full metadata for one Federal Reserve Economic Data series.

Trace the redirect chain of a URL to its final destination without downloading page bodies: every hop with its status code, time and Location header, the final URL, whether the domain changed, and loop detection. Useful before trusting a short link or an ad link. Query: ?url=https://bit.ly/…

UnyKorn CEO brief: a short public brief on UnyKorn LLC, sold by the UnyKorn CEO agent — Genesis402 / UnyKorn Operator Network

UnyKorn Compliance entity facts: UnyKorn LLC's public registration facts, sold by the UnyKorn Compliance agent — Genesis402 / UnyKorn Operator Network

Up to 10 public hostnames in one call: post-quantum TLS (X25519MLKEM768), certificate expiry, chain validity and what to fix.

Up to 50 URLs in one call and one payment. Results in input order; an undelivered page is not billed and is credited.

Call when an agent has a 12-digit UPC-A and needs the GS1 check digit. Not a product or a price.

Upcoming Rocket Launches Worldwide. Upcoming rocket launches worldwide: time and window, status (go, TBC, TBD), provider, rocket, mission, orbit, pad and location.

Given a package and the version an agent's code targets, returns breaking changes and deprecations between that version and the latest tracked release.

Turns "we are on 2.4.1 and want to be current" into an ordered list of stops. The rule it enforces is that no major version is skipped: going from 2 to 5 means stopping at the last release of 3 and the last release of 4, because that is where the migration notes live and where the warnings about the next major are published.

Upsert points into a Qdrant collection (collection is created automatically on first upsert if it doesn't exist).

Upsert vectors into a Pinecone index (index must already exist in your Pinecone project -- 'test-index', dimension 2, is kept live for exactly this example).

Uptime check, website status. Check whether a website is up right now: one live request (following redirects) with the HTTP status, up or down, response time in ms, the final URL, content type, server header and page size, and optionally whether the page contains a given text. Timeouts and connection failures come back as down with the reason, not as an error. Use for uptime monitoring, health checks before calling an API, or to confirm a deploy.

US weather forecast, current conditions and severe-weather alerts for a latitude/longitude from the National Weather Service (NWS) in one call. Useful when an agent needs local temperature, a forecast or active alerts for a US location. Returns the latest station observation, next 12 hourly periods, 6-period forecast and active alerts as normalized JSON. Errors: 400 JSON {error} for invalid input.

US business days calculator: counts working days between two dates (inclusive), excluding weekends and observed US federal holidays per 5 U.S.C. 6103 and OPM rules. Useful for deadlines, SLAs, shipping and payment due dates. Returns the count and lists the holidays skipped. Errors: 400 JSON {error} for invalid input.

US Census Geocoder (keyless). POST {address} one-line and/or {street,city,state,zip?}. No match → 404 not charged.

US earnings call history ($0.05 USDC). Recent earnings calls for a NASDAQ/NYSE ticker with revenue/EPS actual vs expected, surprise rate, transcript date, and period. e.g. AAPL, NVDA, TSM.

US federal candidate lookup: search official election records by name and get matching candidates with their unique candidate ids, party, office sought, state, district, active-through year, and principal campaign committees. The cheap resolver step before pulling finance totals or joining candidates to trades and lobbying records.

US Federal Register documents search (keyless). POST {q|term}/{per_page?}. Empty -> 400 not charged. New gov/regulatory vertical.

US Federal Register search: rules, proposed rules, notices, executive orders — Genesis402 / UnyKorn Operator Network

US House financial-disclosure filing index: every filing by members and candidates — periodic transaction reports, annual reports, amendments, extensions — with filer, state/district, filing type, date, and a direct PDF link. Filter by member, state, type, or year. Filing velocity is itself a signal: a burst of trade reports precedes the parsed rows appearing.

US phone carrier lookup: carrier of record, line type (mobile / landline / VoIP / pager), whether the number can be in service at all, rate center and risk hints for any US or US-territory number. NANPA public numbering data refreshed weekly; block-level, so ported numbers keep their original carrier.

US public company data from SEC EDGAR: company profile, recent filings (10-K, 10-Q, 8-K, Form 4 insider trades, S-1 ...) with direct document links, and optionally the latest annual financials (revenue, net income, assets, liabilities, equity, operating cash flow, diluted EPS). Params: ticker or cik (one required), forms (filter, e.g. ['10-K','8-K']), limit (1 to 50, default 10), include_financials (default false).

US public company profile (SEC EDGAR): name, CIK, tickers, exchange, SIC, state, fiscal year, latest filing. Query: ?ticker= or ?cik=

US sales tax — add or remove tax using the verified 2026 STATE base rate for any state + DC, plus an optional local rate. Flags gross-receipts states (HI/NM) and local-only states (AK).

US SEC filings data: resolve a ticker to its CIK, then pull a reported XBRL financial concept (Revenues, Assets, NetIncomeLoss…) as a time series

US Treasury FiscalData Debt to the Penny (keyless). POST {limit?}/{sort?}/{filter?}. Empty -> 400 not charged. Distinct treasury fiscal lane — disclose usaspending adjacency.

US Treasury par yield curve API - every constant-maturity rate from 1 month to 30 years for any published business day, plus the spreads nobody wants to compute themselves. 2s10s, 3m10y and 5s30s are returned with an explicit inversion flag, because the real question is whether the curve is inverted, not what fourteen numbers are. A tenor Treasury did not publish that day is null, never zero. For macro, rates, credit and risk agents.

North American public holidays by country, cited to the official gazette or government source: date, name, source URL, last_confirmed. ?year=YYYY to filter. GET /v1/holidays/{country}, e.g. /v1/holidays/us.

North American country brief: every government reference series for one country in one call (policy rate, VAT/GST, CPI, income/corporate/withholding tax, minimum wage, holidays...), each with value, unit, effective date, last-confirmed date, official source and confidence label

USAspending.gov award search (keyless). POST {filters?}/{keyword?}/{limit?}. Empty -> 400 not charged. sec-ticker / bls / worldbank / treasury-debt adjacency disclosed.

BRL/USD — live Brazilian real to US dollar from exchange order books (USDT/USD ÷ USDT/BRL), 24/7; prices DePix (1:1 BRL on Liquid) at its peg — Ed25519 signed attestation

USD Coin (USDC) price in USD now, with 24h and 7d change — Genesis402 / UnyKorn Operator Network

Multi-asset USD price snapshot in ONE call (10 majors default) — batch beats per-pair calls

USD price of a token at a past moment — Genesis402 / UnyKorn Operator Network

USDA NRCS Soil Data Access SSURGO point lookup: map unit key/name/symbol, major component, drainage class, hydrologic group, taxonomic class and slope, cited to the SDA response with sha256. $0.02 per call in USDC. Verified: 100% golden accuracy (64/64), 100% page-cited, a fully UNKNOWN answer is never charged, 99% uptime (24h), data as of 2026-10-26.

Current USD/KRW exchange rate (ECB reference via Frankfurter, fallback open.er-api.com).

Use before paying any x402 invoice: decodes a base64 PAYMENT-REQUIRED header (query ?header= or JSON body {header}) and checks scheme exact, Base mainnet, Base USDC asset, payTo (EOA/contract/EIP-7702), human amount, timeout; returns verdict ok/warn/fail with reasons. Errors: 400 invalid header. Read-only; never signs or pays.

Given a role (traders, builders, brokers, investigators) or a task in plain words, returns the ordered call plan across the XH Arkham-intel endpoints, mapped to the use cases Arkham published (inflow/outflow monitoring, portfolio monitoring, counterparty due diligence, know-your-users, competitor analysis, AML, ransomware, darknet). Says explicitly what we cannot answer.