Duo Data Utilities: IBAN, ISIN, VAT and Tax ID, Barcode, Timezone, Geo APIs

IBAN, ISIN, VAT/tax ID and GTIN barcode validation plus 29 more utilities for AI agents. Pay per call ($0.05 USDC on Base via x402), no API key, no signup.

Timezone and DST, geo distance and geohash, hashes and JWT decoding, airport, country, currency and NUTS lookups, money split, base conversion and more. Every call is one HTTP GET, paid per request.

Also crypto derivatives data for trading agents: perp funding rates, funding arbitrage, open interest, futures basis, implied volatility, liquidations and order book depth across Bybit, Hyperliquid, dYdX, Gate, Kraken, Bitfinex, Deribit and OKX, at $0.003 or $0.005 per call (below).

Install

npm install duo-data-utilities viem

viem creates the wallet account that pays. This package also depends on it. Node.js 20 or later.

Python (not on PyPI, install from GitHub):

pip install "git+https://github.com/hiesem/duo-data-utilities#subdirectory=python"

Quick start

import { privateKeyToAccount } from "viem/accounts";

import { createClient } from "duo-data-utilities";

// Your wallet holds USDC on Base. Read the key from the environment, never a literal. const client = createClient({ account: privateKeyToAccount(process.env.DUO_PAYER_KEY as 0x${string}) });

const iban = await client.iban.validate({ iban: "NL91 ABNA 0417 1643 00" }); // $0.05 console.log(iban.valid, iban.country); // true NL

Counterparty check

checkCounterparty runs three checks in one call: IBAN (/v1/id/iban), tax ID (/v1/id/national) and country (/v1/ref/country). It costs $0.15.

const check = await client.checkCounterparty({

iban: "NL91 ABNA 0417 1643 00", country: "NL", taxIdType: "bsn", taxId: "111222333", }); console.log(check.verdict, check.reasons); // "pass", "fail" or "review"

• fail: the IBAN or the tax ID fails its checksum, the country is not an ISO 3166-1 country, or the API rejects an input as malformed.
• review: the IBAN country differs from the tax ID country, or the API does not cover that country or tax ID kind.
• pass: every check passed.

Structure and checksum only. The check does not query a company register, a bank or a tax authority, and it does not confirm that an account exists. UK is read as GB.

Crypto derivatives data: perp funding rates, open interest, futures basis, implied volatility, liquidations, order book depth

client.derivs calls https://derivs.duoleads.com: crypto derivatives data from 8 exchanges (Bybit, Hyperliquid, dYdX, Gate, Kraken, Bitfinex, Deribit, OKX) for trading agents and bots. Perpetual futures (perp) funding rates with predicted funding, funding rate history and a funding arbitrage scanner, a perp screener, open interest (OI), futures basis and term structure, options implied volatility (IV), skew and max pain, liquidations, and order book depth with slippage. $0.003 or $0.005 per call, same wallet, same x402 payment, no API key.

import { privateKeyToAccount } from "viem/accounts";

import { createClient, createDerivsClient } from "duo-data-utilities";

const account = privateKeyToAccount(process.env.DUO_PAYER_KEY as 0x${string}); const client = createClient({ account });

const funding = await client.derivs.fundingRates({ coin: "BTC" }); // $0.003 for (const v of funding.venues) console.log(v.venue, v.apr_pct, v.next_funding_time);

const arb = await client.derivs.fundingArbitrage({ min_apr: 20, min_volume_usd: 1_000_000 }); // $0.005, all coins const snap = await client.derivs.derivativesSnapshot({ coin: "ETH" }); // $0.005: funding, OI, basis, liquidations, long/short

// Or a derivs-only client: const derivs = createDerivsClient({ account }); await derivs.openInterest({ coin: "SOL" }); // $0.003

import os

from eth_account import Account from duo_data_utilities import DerivsClient, DuoClient

client = DuoClient(Account.from_key(os.environ["DUO_PAYER_KEY"])) rates = client.derivs.funding_rates(coin="BTC") # $0.003 book = client.derivs.orderbook(coin="BTC", size_usd=250_000) # $0.003 derivs = DerivsClient(Account.from_key(os.environ["DUO_PAYER_KEY"])) # derivs only

• Price guard: client.derivs has its own cap, $0.005 per call by default. createClient({ account, derivs: { maxPriceUsd: 0.003 } }) refuses the $0.005 routes (Python: derivs_max_price_usd=0.003). The other rules are the same: Base USDC only, only to 0xCD673f7e1daD254347AEab6be0DEFe8b9C6b3A39, nothing is signed before the check.
• Not charged: bad input is a free 400 with error.expected. When fewer venues answer than the route needs, the answer is a 503 and nothing is charged. Both throw DuoApiError.
• Answers are the JSON body itself (no data envelope), with venues_missing, units, as_of and a see_also pointer to the next useful route. TypeScript types: DerivsFundingRatesData and so on.
• Coins: BTC, btc, BTCUSDT, BTC-PERP, XBT, 1000PEPE and kPEPE all name a coin.
• MCP: the same 10 tools at https://derivs.duoleads.com/mcp. Snippets for Claude Code, Claude Desktop, Cursor and VS Code: mcp/README.md.
• Data only, not investment advice, not affiliated with any exchange.

Derivs docs: https://derivs.duoleads.com/docs · OpenAPI: https://derivs.duoleads.com/openapi.json · Index: https://derivs.duoleads.com/llms.txt · Terms: https://derivs.duoleads.com/terms · Privacy: https://derivs.duoleads.com/privacy

SEO keyword data: search volume, CPC, keyword difficulty, keyword ideas, Google Trends

client.keywords calls https://keywords.duoleads.com. It returns Google keyword search volume, CPC, competition, keyword difficulty and search intent (Google Ads data), keyword ideas for a seed, and Google Trends (interest over time, related queries, interest by region). Calls cost $0.03 to $0.045 each and use the same wallet and the same x402 payment, with no API key.

const volume = await client.keywords.searchVolume({ keywords: ["phone", "watch"], country: "us" }); // $0.04, up to 20 keywords

const overview = await client.keywords.keywordOverview({ keywords: myList }); // $0.04, up to 100 keywords (POST) const ideas = await client.keywords.keywordIdeas({ keyword: "seo api", limit: 50 }); // $0.04 (POST) const trend = await client.keywords.trend({ keyword: "seo tools", timeframe: "past_12_months" }); // $0.045

// Or a keywords-only client: const keywords = createKeywordsClient({ account }); await keywords.relatedQueries({ keyword: "seo api", country: "us" }); // $0.03

• Price guard: client.keywords has its own cap, $0.045 per call by default. createClient({ account, keywords: { maxPriceUsd: 0.04 } }) refuses the $0.045 trend route. The other rules are the same: Base USDC only, only to 0xCD673f7e1daD254347AEab6be0DEFe8b9C6b3A39, and nothing is signed before the check.
• Errors: a bad input is a free 400. An upstream failure is a 503 with "nothing was charged". Both throw DuoApiError.
• MCP: the same 6 tools are at https://keywords.duoleads.com/mcp.

Keyword docs: https://keywords.duoleads.com/docs · OpenAPI: https://keywords.duoleads.com/openapi.json · Index: https://keywords.duoleads.com/llms.txt

Methods

Every method costs $0.05 per call. Each method's JSDoc gives the route and the parameters. client.call(path, params) calls any route, and client.callWithReceipt(path, params) also returns the settlement receipt.

| text.similarity | /v1/text/similarity | String similarity: Levenshtein, Jaro-Winkler distance