Search arXiv papers | Vextorium

Search scientific papers on arXiv (AI, physics, maths, economics...): title, authors, abstract, categories, dates and PDF link; by relevance or newest, with category filter (cs.AI, cs.CR, q-fin...).

Country profile: name, ISO codes, capital and its coordinates, region, income level, phone prefix, time zones and latest population and GDP per capita. World Bank and libphonenumber data.

Summary of a Wikipedia article in any language: title, short description, lead paragraph, image, coordinates, link and Wikidata id. If the title is not exact it returns the closest article, flagged as approximate, with alternatives.

Most read Wikipedia articles in a language on a given day (yesterday by default): what people are looking up, with views and rank, technical pages removed. A signal of current events and trends.

Historical ECB euro reference exchange rate for any date since 1999 and conversion between any two published currencies.

Test your x402 client or agent for the minimum price: confirms the payment arrived and echoes back the network, scheme, payer and amount the server saw, your IP, user agent, time and any 'eco' text you send.

Your public IP address as the server sees it, IPv4/IPv6, whether it is public or private, plus your user agent. Calculated by Vextorium, no third-party lookups. Check where an agent exits from or whether a proxy/VPN works.

Key indicators of any country: GDP, real growth, GDP per capita, inflation, population, unemployment, public debt, exports, life expectancy and internet use, with the last years of each. World Bank open data.

Daily ECB reference exchange rate of a currency against the euro for up to 5 years: latest, change, high, low, average and annualized volatility, with the series.

Structured facts from Wikidata about a person, company, place or work by name or Q-id: type, country, population, dates, founders, headquarters, website, ticker, currency, version... labelled in your language. Grounded answers without free text.

Exchange rates against the US dollar for the ~30 currencies published by the ECB (EUR, GBP, JPY, CHF, CNY, INR, BRL, MXN, TRY, ZAR...), with date and 1-month change. Cross rates calculated from ECB reference rates.

Query a JSON document with JSONPath, including filters and functions ($.items[?(@.price > 10)].name, $..id...): matching values and their paths. Send the JSON in the data field or a URL to fetch it.

Price change in % of up to 20 cryptocurrencies over 1h, 24h or 7d, sorted from best to worst, with current price. Tickers of the ~190 largest coins (alternative.me data).

Official European Central Bank euro reference exchange rates (about 30 currencies) and currency conversion between any two of them, with reference date.

Current price of up to 50 cryptocurrencies by ticker (BTC, ETH, SOL, XRP...) in USD or any ECB currency (EUR, GBP, JPY...). Covers the ~190 largest coins listed by alternative.me; currency conversion with ECB reference rates.

Email validation: syntax, domain MX records and disposable-domain flag. Sends no email; the address is not stored.

EVM developer utilities: keccak256 hash, function selector from a signature, EIP-55 checksum address and wei/gwei/ether conversion.

Impermanent loss calculator for Uniswap v2 (full range) and v3/v4 concentrated ranges: IL vs holding, out-of-range flag and final token mix.

Extract keywords and keyphrases from a text without AI (RAKE algorithm scoring frequency and degree), in Spanish or English, plus most frequent words. For tagging, indexing and SEO.

Euro area AAA government bond yield curve (zero-coupon, 3 months to 30 years) estimated by the ECB, with change in basis points versus N days ago and the 10y-2y slope.

Spanish business-day calculator: count business days between dates or add N business days, using Spain's national public holidays.

One endpoint for hashing and encoding: sha256, sha512, sha3, keccak256, md5, sha1, blake2, ripemd160, crc32, all-hashes-at-once, HMAC, base64/base64url, hex, URL and base58 encode/decode, JWT decode (with expiry check) and UUID v4/v5. Input as text, hex or base64.

Spanish Official State Gazette (BOE) daily summary: every item of a given day with section, department and official links, filterable by section (e.g. civil service exams 'oposiciones', appointments, public procurement), department or title keywords.

Reference data for a blockchain by its chainId: name, gas/native token, block explorers, number of public RPCs and website. Utility for multi-chain agents. Live from chainid.network (ethereum-lists, open data).

World stock exchanges clock: status (open, closed, lunch break), local time, today's session and next open for NYSE, Toronto, London, Euronext, Xetra, Madrid, Zurich, Tokyo, Hong Kong, Shanghai, India and Sydney.

Encode a contract function call (calldata) from its signature and arguments, e.g. transfer(address,uint256) with [to, amount]: selector and hex data ready to sign or simulate.

Find airports by IATA/ICAO code, name or city, or the nearest to coordinates: name, codes, city, country, coordinates, elevation and scheduled service. OurAirports open data.

Convert APR to APY or APY to APR for any compounding frequency (continuous, daily, hourly, per block...) and optionally project the final value and gain of a deposit over N days. Useful to compare DeFi yields.

BIC/SWIFT code validation and parsing: bank, country, location and branch codes, test-code flag.

DNS records of a domain with TTL: A, AAAA, CNAME, MX, NS, TXT, SOA, CAA, SRV, HTTPS. Choose the types or get the common ones at once.

Details of a CVE vulnerability (e.g. CVE-2021-44228) from the official CVE Program (MITRE CVE Services): title, description, severity and CVSS vectors, affected products and versions and references, with MITRE's required copyright and license notice.

EU VAT number format validation for all member states (plus Spanish check digit). Does not query VIES.

IBAN validation (ISO 13616 mod-97 and per-country length, SEPA membership; for Spain also the national CCC check digits and bank name). Computed locally, IBAN is not stored.

Decode a JWT and verify its signature with the public keys of a JWKS URL (RS256, ES256, EdDSA...) or an HMAC secret, checking expiry, audience and issuer; returns header, claims and the exact reason if invalid. Tokens are not stored.

All links on a page classified as internal or external, with anchor text, nofollow/sponsored, new-tab flags and the most linked external domains. For SEO, crawling and audits.

Harmonised inflation (HICP annual rate) of any EU/EEA country, the EU or the euro area for the last months; with country=todos, a ranking of all countries for the latest month. Official Eurostat data.

US stock market clock (NYSE/Nasdaq): open, closed, pre-market or after-hours now (or at a given time), holiday reason, early closes, next open/close and upcoming holidays. Key for 24/7 tokenized stocks.

Repair broken JSON, typical of LLM output: strips ```json fences, comments and surrounding text, trailing commas, single quotes, unquoted keys, Python True/None and unclosed brackets. Returns the object and clean JSON and, if you pass a JSON Schema, whether it validates and why not.

Official public holidays of 150+ countries and their regions (Spanish autonomous communities, US states, German Länder...) for a year, whether a given date is a holiday, and the next holiday.

General government gross debt (Maastricht) as % of GDP for any European country, quarterly; without a country, a ranking with the latest figure of each. Official Eurostat data.

Find a company's LEI (Legal Entity Identifier) by name, or the record of a LEI: legal name, country, legal form, address, entity and registration status, renewal date, direct parent and company register number.

Test a regular expression against a text: every match with position, groups and named groups, plus the result of a substitution if you pass a replacement. Flags i, m, s, x. Time-limited, safe against catastrophic backtracking.

US listed company fundamentals from public SEC filings (XBRL): last quarters and years of revenue, net income, diluted EPS, operating cash flow, assets, liabilities, equity, cash, dividends and shares outstanding.

Run a read-only SQL query (SELECT/WITH, WHERE, GROUP BY, ORDER BY, window functions...) over a CSV loaded as table «datos» in a temporary in-memory SQLite database, and get the rows as JSON.

Email security of a domain: MX, SPF (final policy, multiple-record and lookup-limit problems), DMARC (policy, subdomains, reporting), MTA-STS, TLS-RPT and BIMI, with a score and recommendations. Detects spoofable domains.

Real quarterly GDP growth (seasonally adjusted) of any European country, the EU or the euro area: quarter-on-quarter and year-on-year; without a country, a ranking for the latest quarter. Official Eurostat data.

Year-on-year change of house prices (house price index, all dwellings) for any European country, or a ranking of all. Official Eurostat data.

Recent additions to the EU consolidated sanctions list (persons and entities designated in the last N days) with program (country or regime), type and date. Keep a compliance screen up to date.

Perpetual futures calculator (isolated margin): liquidation price and distance, notional and size, PnL at stop-loss and take-profit, reward/risk ratio, and position sizing to risk a fixed USD amount.

Real effective exchange rate index (2010 = 100) from the World Bank: rises mean the currency gets dearer and the country loses competitiveness. Ranking with the latest annual change, or one country's yearly series.